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Thank you, I DO always want to understand this better and I appreciate
people like you taking the time to explain it to non-EE's like myself.

Thanks again,

Nick

"arthur" wrote in message
...
No. You have a DC mental image of how a capacitor operates.

There are 2 passive reactive devices for AC: capacitors and inductors.
Reactance is the name given to the resistance, measured in Ohms, of an
AC signal.

Place a resistance in a circuit and it must attenuate the signal by
converting some of the power to heat. Impedence is resistance with a
PhD.

I thought you would rather know the facts.

arthur


On Tue, 11 Sep 2007 19:02:29 -0700, "MOSFET"
wrote:
I was just pointing out that capacitors, by their nature, can discharge
current and THEREFORE it stands to reason that a signal may be boosted

EVER
SO SLIGHTLY (and attenuated as well), again, I WOULD NOT except it to be
audible.




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DC is not audible.

Well sure it is, for a SPLIT second and then the cone remains stationary
(out or in depending on the voltage, positive or negative).

MOSFET


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DC is not audible.

It would probably sound like one loud THUMP, and then silence. So THAT'S
audible.

MOSFET


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the more complicated it is. the more troubles you'll have.

Geez, Bob, that's true and ALWAYS good advice.

Man, you're on a roll, keep it up and I might stop calling you a troll.....


(you're wondering "is that a compliment or not:?")

MOSFET


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Too easy. The hard part is that reactance ( the X of Z = R + X )
changes as the AC frequency. So the effect is one can attenuate some
frequencies more or less than others ( the how of crossovers ). This
can fool the non electonics person into thinking that some frequencies
are enhanced at the expense of others. And now you know.

arthur

ps Z = R + X is an understatement of the complexity but we all know
that we don't have to know that jazz since we have really smart
computers to do the hard stuff.


On Wed, 12 Sep 2007 10:42:37 -0700, "MOSFET"
wrote:
Thank you, I DO always want to understand this better and I appreciate
people like you taking the time to explain it to non-EE's like myself.

Thanks again,

Nick



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touche



On Wed, 12 Sep 2007 10:49:06 -0700, "MOSFET"
wrote:

DC is not audible.

It would probably sound like one loud THUMP, and then silence. So THAT'S
audible.

MOSFET

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Don't ya hate the "nit-pickers". I've been nitpicked so many times I COULD
NOT resist.

MOSFET

"arthur" wrote in message
...
touche



On Wed, 12 Sep 2007 10:49:06 -0700, "MOSFET"
wrote:

DC is not audible.

It would probably sound like one loud THUMP, and then silence. So THAT'S
audible.

MOSFET




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"MOSFET" wrote in message
...
Don't ya hate the "nit-pickers". I've been nitpicked so many times I
COULD
NOT resist.

MOSFET

"arthur" wrote in message
...
touche



On Wed, 12 Sep 2007 10:49:06 -0700, "MOSFET"
wrote:

DC is not audible.

It would probably sound like one loud THUMP, and then silence. So
THAT'S
audible.

MOSFET


Actually, the thump would be caused by the change in signal from its old
voltage to its new one (ie: the transition from 0v to 12v). This would not
be DC, but a momentary AC riding a DC level.

How's that for nitpicking? :-p

Chris


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also, not musical, since the rise time would be close to zero and thus
a square wave which is far from musical for "normal" types.




On Wed, 12 Sep 2007 21:08:18 -0700, "Christopher \"Torroid\" Ott"
spamtrap at ottelectronics dot com wrote:

Actually, the thump would be caused by the change in signal from its old
voltage to its new one (ie: the transition from 0v to 12v). This would not
be DC, but a momentary AC riding a DC level.

How's that for nitpicking? :-p

Chris

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On Sep 13, 1:20 am, arthur wrote:
also, not musical, since the rise time would be close to zero and thus
a square wave which is far from musical for "normal" types.

On Wed, 12 Sep 2007 21:08:18 -0700, "Christopher \"Torroid\" Ott"
spamtrap at ottelectronics dot com wrote:

Actually, the thump would be caused by the change in signal from its old
voltage to its new one (ie: the transition from 0v to 12v). This would not
be DC, but a momentary AC riding a DC level.


How's that for nitpicking? :-p


Chris


you might hear a mechanical sound in the speaker though if the change
in voltage is big enough



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Yes I thought of that later. The coloration and almost infinite
possible harmonics. A speaker is not a square wave device.

Hey, its for fun, remember?




On Thu, 13 Sep 2007 05:09:55 -0700, Mariachi
wrote:

you might hear a mechanical sound in the speaker though if the change
in voltage is big enough

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On Sep 13, 12:53 pm, arthur wrote:
Yes I thought of that later. The coloration and almost infinite
possible harmonics. A speaker is not a square wave device.

Hey, its for fun, remember?

On Thu, 13 Sep 2007 05:09:55 -0700, Mariachi
wrote:



you might hear a mechanical sound in the speaker though if the change
in voltage is big enough


An ideal speaker could play a square wave w/ the infinite harmonics
that make up the square, as long as the square wave oscillates around
zero volts... say 5 volts to -5 volts with a frequency greater than 20
Hz.

But in the real world... there is no such thing as ideal.

Actually, a speaker can play a square wave to some extent, although it
may not play all the frequencies because of crosstalk. I hooked my
ghetto sony speakers to an AC generator with the square wave option
enabled, and you could actually hear some tones coming out of the
speaker. I thought it was interesting

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Actually, the thump would be caused by the change in signal from its old
voltage to its new one (ie: the transition from 0v to 12v). This would not
be DC, but a momentary AC riding a DC level.

How's that for nitpicking? :-p

Chris


WOW. You win "nit-picking" prize!!! Nice work, though I don't quite
understand what you are saying (but, of course, that can often be a key
nit-picking strategy).

Nick





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http://www.answers.com/topic/square-wave?cat=technology

again, the DC vs AC mentality as though they are the only wave forms.

arthur





On Sat, 15 Sep 2007 14:14:45 -0700, I. Care
wrote:

Let's get really nit-picky. A state change from 0vDC to 12vDC is a
level shift. AC is "Electric current that reverses direction
periodically, usually many times per second." In this case there is no
reverse of direction, it goes from a steady 0vDC to steady 12vDC until
you remove the signal so there is no periodicity.

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discount car stereos .com
has all the subs n sub amps...2000rms+
lanzar. under afew hundred dollars.
WOW!



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car discount stereos .com

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On Sep 10, 8:11 pm, (bob wald) wrote:
ok , just about every connection.


So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.

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This is an-ongoing debate we've been having here at RAC for years now. It
goes a little like this:

First, keep in mind 6x9's were developed by car-makers in order to maximize
space in the rear-shelf. Do you see any 6x9's on home speakers? No. And
here's the reason (although the big debate is whether the following reason
is audible) why:

As you probably know, speakers work by sending alternating current through a
voice coil. This voice coil sits in a magnetic field (this is the larger
magnet located behind every speaker) and when alternating current is applied
it moves up and down, like an electric motor going forward and reverse over
and over really fast. The voice coil is connected to the cone, and it is
this in and out movement of the cone that vibrates the air and produces
sound (a little accousitc principles 101).

So think about a voice coil, it is round. Now think about a 6x9" cone, it
is not. So when the voice coil moves, it will have moved the shorter
distance of cone (the 6") VERY SLIGHTLY ahead of the 9" distance. Of
course, we're talking VERY minute differences.

In fact, when playing a higher frequency (where the voice coil is moving
VERY fast up and down) it's possible to imagine that the 6" part of the cone
has moved up and is ALREADY beggining to move down WHILE THE 9" DISTANCE IS
STILL MOVING UP. Again, these are extremelly small differences and
obviously the stiffness of the cone come into play. The trouble with cone
stiffnes, though, is that my making a stiffer cone to avoid this problem,
you also tend to make a HEAVIER cone which comes with it's own set of
problems (lack of efficency for one).

But that is basically what the debate is about and the big question is
whether this problem in design produces audible effects (like distortion,
cancellation, ect.). In a car, where you have much larger noise problems
AND a poor accoustical space, my guess is it is probably not audible.

However, in a home speaker, it very likely would make the speaker a little
less steller than a typical 8" or 6" round speaker when you are talking
strictly about sound quality. Again, I go back to my first point that home
speaker makers DO NOT use 6x9 or any other shape except round to match the
voice coil for perfect linierity of movement. The 6x9 or 3x10 or all those
weird shapes were made by CAR MAKERS to maximize space, NOT accoutical
engineers focussed on what sounds best. And clearly, what will sound best
is a cone that moves perfectly linierly up and down.

MOSFET


wrote in message
ups.com...
On Sep 10, 8:11 pm, (bob wald) wrote:
ok , just about every connection.


So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.




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Default polk 6x9

On Sep 20, 11:41 am, "MOSFET" wrote:
This is an-ongoing debate we've been having here at RAC for years now. It
goes a little like this:

First, keep in mind 6x9's were developed by car-makers in order to maximize
space in the rear-shelf. Do you see any 6x9's on home speakers? No. And
here's the reason (although the big debate is whether the following reason
is audible) why:

As you probably know, speakers work by sending alternating current through a
voice coil. This voice coil sits in a magnetic field (this is the larger
magnet located behind every speaker) and when alternating current is applied
it moves up and down, like an electric motor going forward and reverse over
and over really fast. The voice coil is connected to the cone, and it is
this in and out movement of the cone that vibrates the air and produces
sound (a little accousitc principles 101).

So think about a voice coil, it is round. Now think about a 6x9" cone, it
is not. So when the voice coil moves, it will have moved the shorter
distance of cone (the 6") VERY SLIGHTLY ahead of the 9" distance. Of
course, we're talking VERY minute differences.

In fact, when playing a higher frequency (where the voice coil is moving
VERY fast up and down) it's possible to imagine that the 6" part of the cone
has moved up and is ALREADY beggining to move down WHILE THE 9" DISTANCE IS
STILL MOVING UP. Again, these are extremelly small differences and
obviously the stiffness of the cone come into play. The trouble with cone
stiffnes, though, is that my making a stiffer cone to avoid this problem,
you also tend to make a HEAVIER cone which comes with it's own set of
problems (lack of efficency for one).

But that is basically what the debate is about and the big question is
whether this problem in design produces audible effects (like distortion,
cancellation, ect.). In a car, where you have much larger noise problems
AND a poor accoustical space, my guess is it is probably not audible.

However, in a home speaker, it very likely would make the speaker a little
less steller than a typical 8" or 6" round speaker when you are talking
strictly about sound quality. Again, I go back to my first point that home
speaker makers DO NOT use 6x9 or any other shape except round to match the
voice coil for perfect linierity of movement. The 6x9 or 3x10 or all those
weird shapes were made by CAR MAKERS to maximize space, NOT accoutical
engineers focussed on what sounds best. And clearly, what will sound best
is a cone that moves perfectly linierly up and down.

MOSFET

wrote in message

ups.com...



On Sep 10, 8:11 pm, (bob wald) wrote:
ok , just about every connection.


So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.- Hide quoted text -


- Show quoted text -


Yes, I agree... the 6x9 speaker is a poor design for a speaker. But
if a 6x9 is bad, how much worse a 3x10? I personally don't get why
anyone would make a 3x10. It's retarded if you ask me

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''hub'' 6.5 might sound a tiny bit better over all. but not noticable in
a car situration. n it can be tuned to sound better than a 6.5 if the
6.5 isnt at 100%. but these beginners in car audio dont/cant tell you
the whole story.
plus you have your radio reception to factor in.
plus 20 other things.
if you see a great deal on a 6x9. grab it.



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My '77 Chev half-ton had one of those bad boys.. and only one.. in the very
top of the dash. it's for the farm-boys who just wanted some radio to listen
to while they were headin out to the ol' grain elevators.

one speaker no matter what shape.. is better than none.


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I felt I should add one point. I mentioned several times that home speaker
makers do not use the 6x9" size. This is significant and it demontrates
that those who design home speakers know the 6X9" has drawbacks that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow (as narrow
AS POSSIBLE) in an attempt to reduce difraction effects of the tweeter (it
muddies your trebble, effects imaging, staging, ect). Some speaker makers
try to get around this by building small pods around the tweeter, OR putting
the tweeter all by itself on the top of the speaker, OR just extending the
tweeter out a certain distance. What you WANT to try and avoid at all costs
is a tweeter mounted flush to a large baffle (something, unfortunately, that
was NOT put into practice until the 80's as speakers from the 60's and 70's
seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality as round
speakers, THEY WOULD ALL USE 6x9's as this would create a narrower speaker
with better bass response (in other words, you would have the benefit of a
tower speaker (let's say) only 6" wide, yet you would have the bass making
potential of an 8" speaker). They would jump at the chance to accomplish
this if they could. But, again, they don't do it for the reasons I've
already mentioned. What MANY home speaker manufacturers do is keep the
width VERY small (some 4" and less for tower speakers) yet they are quite
deep (12 inches or MORE) to accomodate bass drivers mounted on the sides of
the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
ups.com...
On Sep 10, 8:11 pm, (bob wald) wrote:
ok , just about every connection.


So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.




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Look, I'm sure you're right and that THERE ARE home speakers that utilize
oval speakers. But look at MOST of the speakers out there that use pistonic
priciples to produce sound (i.e. cones), the cones are round to match the
voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the shape
of the voice coil for PERFECT pistonic linierity.

I was at Best Buy yesterday and the VERY MOST EXPENSIVE ($2,000) speaker
they sold was a tower Vienna Accousitcs speaker that was 4" wide!!!!!
Tweeter difraction IS VERY REAL and the top speaker makers of this world
KNOW THIS.

BTW, I didn't see any oval speakers at Best Buy and Magnolia Hi-Fi the last
time I was there which was within the last couple months (these are two
large retail chains that carry what would be considered low to mid range
speaker brands). What I DID FIND were tower speakers that nearly always
tended to be narrow and deep in an attempt to reduce diffraction.

My only point is that oval speakers would be ALL OVER THE PLACE when it
comes to home speakers if there were no sonic drawbacks to them (or at least
compared to their round bretheren). As you mentioned, these drawbacks
become more pronounced the higher in frequency you go. But you generally
don't even see ovals being used as bass drivers in home speakers. YOU JUST
DON'T SEE THEM.

Now I don't know where you shop that you see all these home speakers
utilizing oval speakers. I am actually curious what that smells like. Do
you have a brand or model in mind that I can find to see this? I AM NOT
trying to challenge you or calling you a liar, I am TRULY curious. As I
said before, on the surface, ovals would be IDEAL in designing the most
narrow speaker you can yet still wanting good bass response.

Again, the fact that MOST home speaker makers NEVER use ovals speaks
volumes. I'm sure there is always an exception, but again, just using
common sense, you want a cone whose shape matches the voice coil for the
BEST linear pistonic movement.

MOSFET

"John Durbin" wrote in message
...
That's simply not true... there have been plenty of home speakers that
used oval cone drivers. Some of the Tandberg teak cabinet models have
them, and I remember a fairly high-end system from Jantzen (spelling?)
that had electrostatics up top and a white oval woofer in the lower
section. That one was someone ahead of its time in that they were
slender towers similar to what people are using for front surrounds
these days, in an era where a floorstanding speaker was more lilely to
be 18" wide and equally deep. At any rate, the shape of the oval woofer
made it a lot easier to get more bass from the system without having to
make it a wider cabinet, just as you theorized below. You may not be
familiar with any home speakers with oval components but they absolutely
exist. I'm sure some basic research on the web would find dozens more
examples.

Frankly, provided the piston is adequately rigid it doesn't matter all
that much what shape it is, up to a point. Certainly lower frequencies
are not affected at all provided the moving element acts in purely
pistonic mode with no gross deflections. Also less symmetrical cones can
be easier to eliminate standing wave distortions on the cone surface,
which can improve accuracy. The technology to control those kinds of
things during driver design through use of tools like finite element
analysis is light-years ahead of where it was when oval drivers were the
mainstay of automotive applications.

You should not use a typical automotive 6x9 as the basis for making
these extrapolated statements. They are generally designed for improved
efficiency & exaggerated midbass output as those are useful in the
average 6x9 application. A component 6.5" driver could have the same
attributes if the designer wanted but would be at an efficiency
disadvantage vs. the 6x9 due to less swept area. You can make that up
with excursion of course but usually that has its own implications in
terms of other non-linear distortions & also added cost. At any rate,
the point is the shape of the cone itself isn't inherently good or bad,
it's more what you do with that shape as part of the overall driver

design.

As to the flush-mounted tweeter on a large flat baffle, a well-executed
design in that form factor can perform very well if the baffle effect is
taken into account when designing the drivers, crossovers etc. You would
have to spend a bunch of money for a slender tower design that will
outperform my JBL L150A's in any appreciable way.

JD

MOSFET wrote:
I felt I should add one point. I mentioned several times that home

speaker
makers do not use the 6x9" size. This is significant and it demontrates
that those who design home speakers know the 6X9" has drawbacks that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow (as

narrow
AS POSSIBLE) in an attempt to reduce difraction effects of the tweeter

(it
muddies your trebble, effects imaging, staging, ect). Some speaker

makers
try to get around this by building small pods around the tweeter, OR

putting
the tweeter all by itself on the top of the speaker, OR just extending

the
tweeter out a certain distance. What you WANT to try and avoid at all

costs
is a tweeter mounted flush to a large baffle (something, unfortunately,

that
was NOT put into practice until the 80's as speakers from the 60's and

70's
seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality as

round
speakers, THEY WOULD ALL USE 6x9's as this would create a narrower

speaker
with better bass response (in other words, you would have the benefit of

a
tower speaker (let's say) only 6" wide, yet you would have the bass

making
potential of an 8" speaker). They would jump at the chance to

accomplish
this if they could. But, again, they don't do it for the reasons I've
already mentioned. What MANY home speaker manufacturers do is keep the
width VERY small (some 4" and less for tower speakers) yet they are

quite
deep (12 inches or MORE) to accomodate bass drivers mounted on the sides

of
the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
ups.com...

On Sep 10, 8:11 pm, (bob wald) wrote:

ok , just about every connection.

So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.









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Christopher \Torroid\ Ott Christopher \Torroid\ Ott is offline
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Default polk 6x9

Linear pistonic movement?

I get that every time I have Taco Bell. Cleans the ol' tubes right out.

Chris :-p


"MOSFET" wrote in message
m...
Look, I'm sure you're right and that THERE ARE home speakers that utilize
oval speakers. But look at MOST of the speakers out there that use
pistonic
priciples to produce sound (i.e. cones), the cones are round to match the
voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the shape
of the voice coil for PERFECT pistonic linierity.

I was at Best Buy yesterday and the VERY MOST EXPENSIVE ($2,000) speaker
they sold was a tower Vienna Accousitcs speaker that was 4" wide!!!!!
Tweeter difraction IS VERY REAL and the top speaker makers of this world
KNOW THIS.

BTW, I didn't see any oval speakers at Best Buy and Magnolia Hi-Fi the
last
time I was there which was within the last couple months (these are two
large retail chains that carry what would be considered low to mid range
speaker brands). What I DID FIND were tower speakers that nearly always
tended to be narrow and deep in an attempt to reduce diffraction.

My only point is that oval speakers would be ALL OVER THE PLACE when it
comes to home speakers if there were no sonic drawbacks to them (or at
least
compared to their round bretheren). As you mentioned, these drawbacks
become more pronounced the higher in frequency you go. But you generally
don't even see ovals being used as bass drivers in home speakers. YOU
JUST
DON'T SEE THEM.

Now I don't know where you shop that you see all these home speakers
utilizing oval speakers. I am actually curious what that smells like. Do
you have a brand or model in mind that I can find to see this? I AM NOT
trying to challenge you or calling you a liar, I am TRULY curious. As I
said before, on the surface, ovals would be IDEAL in designing the most
narrow speaker you can yet still wanting good bass response.

Again, the fact that MOST home speaker makers NEVER use ovals speaks
volumes. I'm sure there is always an exception, but again, just using
common sense, you want a cone whose shape matches the voice coil for the
BEST linear pistonic movement.

MOSFET

"John Durbin" wrote in message
...
That's simply not true... there have been plenty of home speakers that
used oval cone drivers. Some of the Tandberg teak cabinet models have
them, and I remember a fairly high-end system from Jantzen (spelling?)
that had electrostatics up top and a white oval woofer in the lower
section. That one was someone ahead of its time in that they were
slender towers similar to what people are using for front surrounds
these days, in an era where a floorstanding speaker was more lilely to
be 18" wide and equally deep. At any rate, the shape of the oval woofer
made it a lot easier to get more bass from the system without having to
make it a wider cabinet, just as you theorized below. You may not be
familiar with any home speakers with oval components but they absolutely
exist. I'm sure some basic research on the web would find dozens more
examples.

Frankly, provided the piston is adequately rigid it doesn't matter all
that much what shape it is, up to a point. Certainly lower frequencies
are not affected at all provided the moving element acts in purely
pistonic mode with no gross deflections. Also less symmetrical cones can
be easier to eliminate standing wave distortions on the cone surface,
which can improve accuracy. The technology to control those kinds of
things during driver design through use of tools like finite element
analysis is light-years ahead of where it was when oval drivers were the
mainstay of automotive applications.

You should not use a typical automotive 6x9 as the basis for making
these extrapolated statements. They are generally designed for improved
efficiency & exaggerated midbass output as those are useful in the
average 6x9 application. A component 6.5" driver could have the same
attributes if the designer wanted but would be at an efficiency
disadvantage vs. the 6x9 due to less swept area. You can make that up
with excursion of course but usually that has its own implications in
terms of other non-linear distortions & also added cost. At any rate,
the point is the shape of the cone itself isn't inherently good or bad,
it's more what you do with that shape as part of the overall driver

design.

As to the flush-mounted tweeter on a large flat baffle, a well-executed
design in that form factor can perform very well if the baffle effect is
taken into account when designing the drivers, crossovers etc. You would
have to spend a bunch of money for a slender tower design that will
outperform my JBL L150A's in any appreciable way.

JD

MOSFET wrote:
I felt I should add one point. I mentioned several times that home

speaker
makers do not use the 6x9" size. This is significant and it
demontrates
that those who design home speakers know the 6X9" has drawbacks that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow (as

narrow
AS POSSIBLE) in an attempt to reduce difraction effects of the tweeter

(it
muddies your trebble, effects imaging, staging, ect). Some speaker

makers
try to get around this by building small pods around the tweeter, OR

putting
the tweeter all by itself on the top of the speaker, OR just extending

the
tweeter out a certain distance. What you WANT to try and avoid at all

costs
is a tweeter mounted flush to a large baffle (something, unfortunately,

that
was NOT put into practice until the 80's as speakers from the 60's and

70's
seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality as

round
speakers, THEY WOULD ALL USE 6x9's as this would create a narrower

speaker
with better bass response (in other words, you would have the benefit
of

a
tower speaker (let's say) only 6" wide, yet you would have the bass

making
potential of an 8" speaker). They would jump at the chance to

accomplish
this if they could. But, again, they don't do it for the reasons I've
already mentioned. What MANY home speaker manufacturers do is keep the
width VERY small (some 4" and less for tower speakers) yet they are

quite
deep (12 inches or MORE) to accomodate bass drivers mounted on the
sides

of
the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
ups.com...

On Sep 10, 8:11 pm, (bob wald) wrote:

ok , just about every connection.

So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.











  #65   Report Post  
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MOSFET MOSFET is offline
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Posts: 810
Default polk 6x9

LOL

Yes, I think I need to take a linear pistonic movement right now. GET OUT
OF MY WAY!!!!


"Christopher "Torroid" Ott" spamtrap at ottelectronics dot com wrote in
message ...
Linear pistonic movement?

I get that every time I have Taco Bell. Cleans the ol' tubes right out.

Chris :-p


"MOSFET" wrote in message
m...
Look, I'm sure you're right and that THERE ARE home speakers that

utilize
oval speakers. But look at MOST of the speakers out there that use
pistonic
priciples to produce sound (i.e. cones), the cones are round to match

the
voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the

shape
of the voice coil for PERFECT pistonic linierity.

I was at Best Buy yesterday and the VERY MOST EXPENSIVE ($2,000) speaker
they sold was a tower Vienna Accousitcs speaker that was 4" wide!!!!!
Tweeter difraction IS VERY REAL and the top speaker makers of this world
KNOW THIS.

BTW, I didn't see any oval speakers at Best Buy and Magnolia Hi-Fi the
last
time I was there which was within the last couple months (these are two
large retail chains that carry what would be considered low to mid range
speaker brands). What I DID FIND were tower speakers that nearly always
tended to be narrow and deep in an attempt to reduce diffraction.

My only point is that oval speakers would be ALL OVER THE PLACE when it
comes to home speakers if there were no sonic drawbacks to them (or at
least
compared to their round bretheren). As you mentioned, these drawbacks
become more pronounced the higher in frequency you go. But you

generally
don't even see ovals being used as bass drivers in home speakers. YOU
JUST
DON'T SEE THEM.

Now I don't know where you shop that you see all these home speakers
utilizing oval speakers. I am actually curious what that smells like.

Do
you have a brand or model in mind that I can find to see this? I AM NOT
trying to challenge you or calling you a liar, I am TRULY curious. As I
said before, on the surface, ovals would be IDEAL in designing the most
narrow speaker you can yet still wanting good bass response.

Again, the fact that MOST home speaker makers NEVER use ovals speaks
volumes. I'm sure there is always an exception, but again, just using
common sense, you want a cone whose shape matches the voice coil for the
BEST linear pistonic movement.

MOSFET

"John Durbin" wrote in message
...
That's simply not true... there have been plenty of home speakers that
used oval cone drivers. Some of the Tandberg teak cabinet models have
them, and I remember a fairly high-end system from Jantzen (spelling?)
that had electrostatics up top and a white oval woofer in the lower
section. That one was someone ahead of its time in that they were
slender towers similar to what people are using for front surrounds
these days, in an era where a floorstanding speaker was more lilely to
be 18" wide and equally deep. At any rate, the shape of the oval woofer
made it a lot easier to get more bass from the system without having to
make it a wider cabinet, just as you theorized below. You may not be
familiar with any home speakers with oval components but they

absolutely
exist. I'm sure some basic research on the web would find dozens more
examples.

Frankly, provided the piston is adequately rigid it doesn't matter all
that much what shape it is, up to a point. Certainly lower frequencies
are not affected at all provided the moving element acts in purely
pistonic mode with no gross deflections. Also less symmetrical cones

can
be easier to eliminate standing wave distortions on the cone surface,
which can improve accuracy. The technology to control those kinds of
things during driver design through use of tools like finite element
analysis is light-years ahead of where it was when oval drivers were

the
mainstay of automotive applications.

You should not use a typical automotive 6x9 as the basis for making
these extrapolated statements. They are generally designed for improved
efficiency & exaggerated midbass output as those are useful in the
average 6x9 application. A component 6.5" driver could have the same
attributes if the designer wanted but would be at an efficiency
disadvantage vs. the 6x9 due to less swept area. You can make that up
with excursion of course but usually that has its own implications in
terms of other non-linear distortions & also added cost. At any rate,
the point is the shape of the cone itself isn't inherently good or bad,
it's more what you do with that shape as part of the overall driver

design.

As to the flush-mounted tweeter on a large flat baffle, a well-executed
design in that form factor can perform very well if the baffle effect

is
taken into account when designing the drivers, crossovers etc. You

would
have to spend a bunch of money for a slender tower design that will
outperform my JBL L150A's in any appreciable way.

JD

MOSFET wrote:
I felt I should add one point. I mentioned several times that home

speaker
makers do not use the 6x9" size. This is significant and it
demontrates
that those who design home speakers know the 6X9" has drawbacks that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow (as

narrow
AS POSSIBLE) in an attempt to reduce difraction effects of the

tweeter
(it
muddies your trebble, effects imaging, staging, ect). Some speaker

makers
try to get around this by building small pods around the tweeter, OR

putting
the tweeter all by itself on the top of the speaker, OR just

extending
the
tweeter out a certain distance. What you WANT to try and avoid at

all
costs
is a tweeter mounted flush to a large baffle (something,

unfortunately,
that
was NOT put into practice until the 80's as speakers from the 60's

and
70's
seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality as

round
speakers, THEY WOULD ALL USE 6x9's as this would create a narrower

speaker
with better bass response (in other words, you would have the benefit
of

a
tower speaker (let's say) only 6" wide, yet you would have the bass

making
potential of an 8" speaker). They would jump at the chance to

accomplish
this if they could. But, again, they don't do it for the reasons

I've
already mentioned. What MANY home speaker manufacturers do is keep

the
width VERY small (some 4" and less for tower speakers) yet they are

quite
deep (12 inches or MORE) to accomodate bass drivers mounted on the
sides

of
the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They

would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
ups.com...

On Sep 10, 8:11 pm, (bob wald) wrote:

ok , just about every connection.

So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.
















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Mariachi Mariachi is offline
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Posts: 174
Default polk 6x9

Oval speakers does not necessarily use diffraction if the sound waves
do not pass through a slit after the speaker. But you can say that an
oval speaker would spread the sound out more in one direction and less
in the other. In other words, an oval speaker would automatically
focus the sound more in one direction than the other, no slit needed.

Diffraction is when any type of wave passes through a slit or multiple
slits. But using diffraction usually ends up in more destructive
interference of the sound waves, which is probably bad.

  #67   Report Post  
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Matt Ion Matt Ion is offline
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Posts: 420
Default polk 6x9

MOSFET wrote:
Look, I'm sure you're right and that THERE ARE home speakers that utilize
oval speakers. But look at MOST of the speakers out there that use pistonic
priciples to produce sound (i.e. cones), the cones are round to match the
voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the shape
of the voice coil for PERFECT pistonic linierity.


I don't think it's as much matching the shape of the VC, as if it were,
the manufacturers would just use oval VC formers. The other part of the
problem is, your basic cone surround (the flexible bit that attaches the
top of the cone to the rim of the basket) will not flex evenly around an
odd-shaped cone, which in turn can distort the cone itself, leading to
all sorts of sonic weirdness.

But in any case, besides the point that ALMOST NO home speaker
manufacturers use the oval design, absolutely NO sound-reinforcement
speakers have ever used an oval design either.

In short, they are a design anomaly almost exclusively limited to the
car-audio realm. That alone has to tell you that they are far from an
ideal design.
  #68   Report Post  
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Posts: 810
Default polk 6x9

.. The other part of the
problem is, your basic cone surround (the flexible bit that attaches the
top of the cone to the rim of the basket) will not flex evenly around an
odd-shaped cone,


I hadn't thought of that. It appears there are MULTIPLE sonic drawbacks in
using oval speakers. CLEARLY, if you are out to build THE BEST SOUNDING
speaker system you can, oval is not the way to go. Good point, Matt

Nick


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Posts: 810
Default polk 6x9

Oval speakers does not necessarily use diffraction if the sound waves
do not pass through a slit after the speaker.


???????

Mariachi, take a look at this thread and the posts regarding this issue. It
has NOTHING to do with what you are talking about (frankly, I'm not even
sure what you are talking about). I associate slits and diffraction with
something to do with light, not sound. I am talking about something
completly different. In fact, difraction MAY not be an entirely accurate
way to describe this tweeter phenomena. What I AM talking about is a
problem with tweeters flush mounted to large baffles. Then, when these
tweeters play their high frequencies, the sound tends to interact with the
baffle creating subtle unwanted sonic artifacts. The resulting sound will
be muddied and you will lose good imaging (the ability to "see" each
instrument in space) and staging (again, the ability to imagine a 3D space
with a height, width and depth when listening to music).

But we welcome your pressence, I'm not trying to diss or embarras you, it's
just your post has little to do with what we were discussing.

MOSFET


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Mariachi Mariachi is offline
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Posts: 174
Default polk 6x9

On Sep 22, 11:25 pm, "MOSFET" wrote:
Oval speakers does not necessarily use diffraction if the sound waves
do not pass through a slit after the speaker.


???????

Mariachi, take a look at this thread and the posts regarding this issue. It
has NOTHING to do with what you are talking about (frankly, I'm not even
sure what you are talking about). I associate slits and diffraction with
something to do with light, not sound. I am talking about something
completly different. In fact, difraction MAY not be an entirely accurate
way to describe this tweeter phenomena. What I AM talking about is a
problem with tweeters flush mounted to large baffles. Then, when these
tweeters play their high frequencies, the sound tends to interact with the
baffle creating subtle unwanted sonic artifacts. The resulting sound will
be muddied and you will lose good imaging (the ability to "see" each
instrument in space) and staging (again, the ability to imagine a 3D space
with a height, width and depth when listening to music).

But we welcome your pressence, I'm not trying to diss or embarras you, it's
just your post has little to do with what we were discussing.

MOSFET


My bad, I was just confused what you meant by diffraction. Since I
know all about diffraction in physics and modern physics, I was just
wanted to point out what it was and what it wasn't...

Talking about Polk speakers... here's some very expensive Polk 6.75"
components
Polk Audio Signature Reference SR6500
http://www.crutchfield.com/S-o18uXmY...07SR6500&wm=su



  #71   Report Post  
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Posts: 810
Default polk 6x9

You know, John, as is ALWAYS the case in the GRAND TRADION OF RAC,
NITPICKING if you use absolutes in this group will ALMOST ALWAYS (see how I
caught myself there) lead to someone who has an example that rebutts it.

I SHOULD NOT have said "NO" speaker makers use the oval speaker in their
designs. You got me. I reviewed my past posts and, INDEED, I did say that.

So yes, I am guilty of being inconsistant. Shoot me. My bad.

I can HONESTLY say that when I wrote that I was thinking about the industry
IN GENERAL though I did not say it. I actually REMEMBER some home speakers
that did use ovals.

BUT, when you compare number of round cone speakers out there vs. number of
oval cone speakers out there (in the home speaker market), the oval speaker
comprises such an incredibly small percentage of the market that I felt
saying the industry "did not use them" was justified.

MOSFET


"John Durbin" wrote in message
...
You were trying to use your perceived absence of oval speakers in "high
end" home speakers to bolster your case that they don't work as well as
round ones. I gave you two specific examples of expensive home speakers
from the past that did use oval speakers. I didn't say everyone used
them, just rebutted your claim that nobody does. Now you want to change
your argument to say MOST instead of NOBODY... I would say that proves
my point.

As to quoting what you found in one Best Buy store as some sort of
reference for what exists in the world of home speakers, give me a break.

Here's a few current examples:

http://www.koiaudio.com/Main/SD63HK_3.html


http://reviews.cnet.com/surround-spe...-30790670.html

http://yhst-9301186439366.stores.yah...25hisisus.html

http://blog.audiovideointeriors.com/907burmced/

Here's one with an oval passive radiator, which is also fairly common:

http://www.stereophile.com/floorloudspeakers/1105thiel/

More oval woofers:

http://www.hedmag.com/Product-Review...m-No-Place.asp


JD


MOSFET wrote:

Look, I'm sure you're right and that THERE ARE home speakers that

utilize
oval speakers. But look at MOST of the speakers out there that use

pistonic
priciples to produce sound (i.e. cones), the cones are round to match

the
voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the

shape
of the voice coil for PERFECT pistonic linierity.

I was at Best Buy yesterday and the VERY MOST EXPENSIVE ($2,000) speaker
they sold was a tower Vienna Accousitcs speaker that was 4" wide!!!!!
Tweeter difraction IS VERY REAL and the top speaker makers of this world
KNOW THIS.

BTW, I didn't see any oval speakers at Best Buy and Magnolia Hi-Fi the

last
time I was there which was within the last couple months (these are two
large retail chains that carry what would be considered low to mid range
speaker brands). What I DID FIND were tower speakers that nearly always
tended to be narrow and deep in an attempt to reduce diffraction.

My only point is that oval speakers would be ALL OVER THE PLACE when it
comes to home speakers if there were no sonic drawbacks to them (or at

least
compared to their round bretheren). As you mentioned, these drawbacks
become more pronounced the higher in frequency you go. But you

generally
don't even see ovals being used as bass drivers in home speakers. YOU

JUST
DON'T SEE THEM.

Now I don't know where you shop that you see all these home speakers
utilizing oval speakers. I am actually curious what that smells like.

Do
you have a brand or model in mind that I can find to see this? I AM NOT
trying to challenge you or calling you a liar, I am TRULY curious. As I
said before, on the surface, ovals would be IDEAL in designing the most
narrow speaker you can yet still wanting good bass response.

Again, the fact that MOST home speaker makers NEVER use ovals speaks
volumes. I'm sure there is always an exception, but again, just using
common sense, you want a cone whose shape matches the voice coil for the
BEST linear pistonic movement.

MOSFET

"John Durbin" wrote in message
...

That's simply not true... there have been plenty of home speakers that
used oval cone drivers. Some of the Tandberg teak cabinet models have
them, and I remember a fairly high-end system from Jantzen (spelling?)
that had electrostatics up top and a white oval woofer in the lower
section. That one was someone ahead of its time in that they were
slender towers similar to what people are using for front surrounds
these days, in an era where a floorstanding speaker was more lilely to
be 18" wide and equally deep. At any rate, the shape of the oval woofer
made it a lot easier to get more bass from the system without having to
make it a wider cabinet, just as you theorized below. You may not be
familiar with any home speakers with oval components but they absolutely
exist. I'm sure some basic research on the web would find dozens more
examples.

Frankly, provided the piston is adequately rigid it doesn't matter all
that much what shape it is, up to a point. Certainly lower frequencies
are not affected at all provided the moving element acts in purely
pistonic mode with no gross deflections. Also less symmetrical cones can
be easier to eliminate standing wave distortions on the cone surface,
which can improve accuracy. The technology to control those kinds of
things during driver design through use of tools like finite element
analysis is light-years ahead of where it was when oval drivers were the
mainstay of automotive applications.

You should not use a typical automotive 6x9 as the basis for making
these extrapolated statements. They are generally designed for improved
efficiency & exaggerated midbass output as those are useful in the
average 6x9 application. A component 6.5" driver could have the same
attributes if the designer wanted but would be at an efficiency
disadvantage vs. the 6x9 due to less swept area. You can make that up
with excursion of course but usually that has its own implications in
terms of other non-linear distortions & also added cost. At any rate,
the point is the shape of the cone itself isn't inherently good or bad,
it's more what you do with that shape as part of the overall driver


design.

As to the flush-mounted tweeter on a large flat baffle, a well-executed
design in that form factor can perform very well if the baffle effect is
taken into account when designing the drivers, crossovers etc. You would
have to spend a bunch of money for a slender tower design that will
outperform my JBL L150A's in any appreciable way.

JD

MOSFET wrote:

I felt I should add one point. I mentioned several times that home


speaker

makers do not use the 6x9" size. This is significant and it

demontrates
that those who design home speakers know the 6X9" has drawbacks that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow (as


narrow

AS POSSIBLE) in an attempt to reduce difraction effects of the tweeter


(it

muddies your trebble, effects imaging, staging, ect). Some speaker


makers

try to get around this by building small pods around the tweeter, OR


putting

the tweeter all by itself on the top of the speaker, OR just extending


the

tweeter out a certain distance. What you WANT to try and avoid at all


costs

is a tweeter mounted flush to a large baffle (something, unfortunately,


that

was NOT put into practice until the 80's as speakers from the 60's and


70's

seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality as


round

speakers, THEY WOULD ALL USE 6x9's as this would create a narrower


speaker

with better bass response (in other words, you would have the benefit

of

a

tower speaker (let's say) only 6" wide, yet you would have the bass


making

potential of an 8" speaker). They would jump at the chance to


accomplish

this if they could. But, again, they don't do it for the reasons I've
already mentioned. What MANY home speaker manufacturers do is keep the
width VERY small (some 4" and less for tower speakers) yet they are


quite

deep (12 inches or MORE) to accomodate bass drivers mounted on the

sides

of

the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
groups.com...


On Sep 10, 8:11 pm, (bob wald) wrote:


ok , just about every connection.

So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and midrange.











  #72   Report Post  
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Matt Ion Matt Ion is offline
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Posts: 420
Default polk 6x9

John Durbin wrote:
Fine, except that it does still not prove your original primary point
that the round driver is inherently better. My point is that as in most
things audio, it's how you execute the design that makes most of the
difference. Not that there aren't totally useless approaches to audio
that result in some mutant products, there probably are... but oval
speakers fall outside that category & have been proven to work just fine
when used intelligently.


I'd think that once you put aside all the nitpicking and obscure
examples, common sense would dictate that a circular cone is inherently
going to make for a less problematic design than an elliptical one.
Obviously a well-designed and well-built oval speaker will outperform
and "out-quality" a poorly designed and built round one... but all else
being equal, a round speaker will be preferable to an oval one for the
basic fact of simpler (and thus less costly) design and engineering.


Which takes us back to the original question of whether oval speakers
are inherently bad, more specifically 6x9 vs. 6.5 inch drivers. I
maintain that neither you or anyone else here has produced any
legitimate case for that so far. In fact, the one person that did have
anything factual or useful to contribute produced some evidence in favor
of the typically higher sensitivity for the larger cone driver.


Not higher SENSITIVITY, necessary. Higher BASS OUTPUT from the simple
fact of having a larger cone surface, yes... at least when comparing,
say, a 6x9 to a 6.5" round. But compare to an 8" round and that
advantage is gone, as the 8" has a larger surface area again than the 6x9.

What that boils down to is, larger cone = greater bass. It's not like a
6x9 will give you more bass out of the same mounting space as a 6.5 -
it's a LARGER SPEAKER.

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Posts: 810
Default polk 6x9

I agree with Matt that this issue really boils down to common sense. A cone
in the exact same shape as the voice coil will move up and down in a more
linear fashion than a 6X9, especialy if you are talking about a
high-excursion bass speaker cone.

And on the flipside of that, if a 6X9" speaker is playing a much, much
higher frequenies (as I've already mentioned in this thread) I can imagine a
scenario where the 6" distance has gone up and has started it's way back
down while the 9" distance is still going up. Of course we are talking
minutes differences and a high frequncy (where the cone is moving quickly up
and down) for this to occur. BUT IF THIS SCENARIO CAN OCCUR, HOW COULD THAT
NOT CREATE SONIC ARTIFACTS?

If you can explain to me why this scenario would never, ever happen, I might
be willing to concede that oval's are just as good as round speakers.

Come on, if what I described were true, HOW COULD THAT NOT efffect the sound
in subtle ways (loss of focus, muddied soundstage and imaging)?

Do I have first hand experiece with this? Well, I've used a lot of 6X9's in
my day but they have ALWAYS been for rear-fill in a car. I have never
criticaly listened to home speakers with oval drivers. So I'm going to be
careful here and not state as absolute fact something I have never heard
with my own ears.

But my gut tells me that round speakers are superior because they match the
shape of the voice coil (there is a symetry and logic to this). Oval
speakers DO NOT and therefore have a set of problems round speakers do not
have.

Look, my mind is open. I am no EE or engineer of any type, just a hobyist.
If you can tell me why these issues would not come into play in a home
speaker comprised of ovals, I'm all ears.

MOSFET

"John Durbin" wrote in message
...
Fine, except that it does still not prove your original primary point
that the round driver is inherently better. My point is that as in most
things audio, it's how you execute the design that makes most of the
difference. Not that there aren't totally useless approaches to audio
that result in some mutant products, there probably are... but oval
speakers fall outside that category & have been proven to work just fine
when used intelligently.

It may come across as nitpicking but when you express any opinion around
here - particularly in the form of an absolute - and then use heavily
flawed statements of fact to bolster it, you're probably going to draw a
rebuttal (if anyone's paying attention that knows better, anyway).

Which takes us back to the original question of whether oval speakers
are inherently bad, more specifically 6x9 vs. 6.5 inch drivers. I
maintain that neither you or anyone else here has produced any
legitimate case for that so far. In fact, the one person that did have
anything factual or useful to contribute produced some evidence in favor
of the typically higher sensitivity for the larger cone driver.

I'm NOT trying to say the 6x9 is necessarily better, don't get me wrong.
But if it isn't, it'll more likely be because the design of a particular
example was compromised somewhere along the way for reasons of cost,
manufacturability, stupid input from sales or marketing, poor
engineering work, or any of the other myriad of reasons that often
handicap the final product than because the oval shape made it
impossible to execute properly.

JD

MOSFET wrote:

You know, John, as is ALWAYS the case in the GRAND TRADION OF RAC,
NITPICKING if you use absolutes in this group will ALMOST ALWAYS (see

how I
caught myself there) lead to someone who has an example that rebutts it.

I SHOULD NOT have said "NO" speaker makers use the oval speaker in their
designs. You got me. I reviewed my past posts and, INDEED, I did say

that.

So yes, I am guilty of being inconsistant. Shoot me. My bad.

I can HONESTLY say that when I wrote that I was thinking about the

industry
IN GENERAL though I did not say it. I actually REMEMBER some home

speakers
that did use ovals.

BUT, when you compare number of round cone speakers out there vs. number

of
oval cone speakers out there (in the home speaker market), the oval

speaker
comprises such an incredibly small percentage of the market that I felt
saying the industry "did not use them" was justified.

MOSFET


"John Durbin" wrote in message
...

You were trying to use your perceived absence of oval speakers in "high
end" home speakers to bolster your case that they don't work as well as
round ones. I gave you two specific examples of expensive home speakers
from the past that did use oval speakers. I didn't say everyone used
them, just rebutted your claim that nobody does. Now you want to change
your argument to say MOST instead of NOBODY... I would say that proves
my point.

As to quoting what you found in one Best Buy store as some sort of
reference for what exists in the world of home speakers, give me a

break.

Here's a few current examples:

http://www.koiaudio.com/Main/SD63HK_3.html




http://reviews.cnet.com/surround-spe...-30790670.html

http://yhst-9301186439366.stores.yah...25hisisus.html

http://blog.audiovideointeriors.com/907burmced/

Here's one with an oval passive radiator, which is also fairly common:

http://www.stereophile.com/floorloudspeakers/1105thiel/

More oval woofers:

http://www.hedmag.com/Product-Review...m-No-Place.asp


JD


MOSFET wrote:


Look, I'm sure you're right and that THERE ARE home speakers that


utilize

oval speakers. But look at MOST of the speakers out there that use


pistonic

priciples to produce sound (i.e. cones), the cones are round to match


the

voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the


shape

of the voice coil for PERFECT pistonic linierity.

I was at Best Buy yesterday and the VERY MOST EXPENSIVE ($2,000)

speaker
they sold was a tower Vienna Accousitcs speaker that was 4" wide!!!!!
Tweeter difraction IS VERY REAL and the top speaker makers of this

world
KNOW THIS.

BTW, I didn't see any oval speakers at Best Buy and Magnolia Hi-Fi the


last

time I was there which was within the last couple months (these are two
large retail chains that carry what would be considered low to mid

range
speaker brands). What I DID FIND were tower speakers that nearly

always
tended to be narrow and deep in an attempt to reduce diffraction.

My only point is that oval speakers would be ALL OVER THE PLACE when it
comes to home speakers if there were no sonic drawbacks to them (or at


least

compared to their round bretheren). As you mentioned, these drawbacks
become more pronounced the higher in frequency you go. But you


generally

don't even see ovals being used as bass drivers in home speakers. YOU


JUST

DON'T SEE THEM.

Now I don't know where you shop that you see all these home speakers
utilizing oval speakers. I am actually curious what that smells like.


Do

you have a brand or model in mind that I can find to see this? I AM

NOT
trying to challenge you or calling you a liar, I am TRULY curious. As

I
said before, on the surface, ovals would be IDEAL in designing the most
narrow speaker you can yet still wanting good bass response.

Again, the fact that MOST home speaker makers NEVER use ovals speaks
volumes. I'm sure there is always an exception, but again, just using
common sense, you want a cone whose shape matches the voice coil for

the
BEST linear pistonic movement.

MOSFET

"John Durbin" wrote in message
.. .


That's simply not true... there have been plenty of home speakers that
used oval cone drivers. Some of the Tandberg teak cabinet models have
them, and I remember a fairly high-end system from Jantzen (spelling?)
that had electrostatics up top and a white oval woofer in the lower
section. That one was someone ahead of its time in that they were
slender towers similar to what people are using for front surrounds
these days, in an era where a floorstanding speaker was more lilely to
be 18" wide and equally deep. At any rate, the shape of the oval

woofer
made it a lot easier to get more bass from the system without having

to
make it a wider cabinet, just as you theorized below. You may not be
familiar with any home speakers with oval components but they

absolutely
exist. I'm sure some basic research on the web would find dozens more
examples.

Frankly, provided the piston is adequately rigid it doesn't matter all
that much what shape it is, up to a point. Certainly lower frequencies
are not affected at all provided the moving element acts in purely
pistonic mode with no gross deflections. Also less symmetrical cones

can
be easier to eliminate standing wave distortions on the cone surface,
which can improve accuracy. The technology to control those kinds of
things during driver design through use of tools like finite element
analysis is light-years ahead of where it was when oval drivers were

the
mainstay of automotive applications.

You should not use a typical automotive 6x9 as the basis for making
these extrapolated statements. They are generally designed for

improved
efficiency & exaggerated midbass output as those are useful in the
average 6x9 application. A component 6.5" driver could have the same
attributes if the designer wanted but would be at an efficiency
disadvantage vs. the 6x9 due to less swept area. You can make that up
with excursion of course but usually that has its own implications in
terms of other non-linear distortions & also added cost. At any rate,
the point is the shape of the cone itself isn't inherently good or

bad,
it's more what you do with that shape as part of the overall driver

design.


As to the flush-mounted tweeter on a large flat baffle, a

well-executed
design in that form factor can perform very well if the baffle effect

is
taken into account when designing the drivers, crossovers etc. You

would
have to spend a bunch of money for a slender tower design that will
outperform my JBL L150A's in any appreciable way.

JD

MOSFET wrote:


I felt I should add one point. I mentioned several times that home

speaker


makers do not use the 6x9" size. This is significant and it


demontrates

that those who design home speakers know the 6X9" has drawbacks that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow (as

narrow


AS POSSIBLE) in an attempt to reduce difraction effects of the

tweeter

(it


muddies your trebble, effects imaging, staging, ect). Some speaker

makers


try to get around this by building small pods around the tweeter, OR

putting


the tweeter all by itself on the top of the speaker, OR just

extending

the


tweeter out a certain distance. What you WANT to try and avoid at

all

costs


is a tweeter mounted flush to a large baffle (something,

unfortunately,

that


was NOT put into practice until the 80's as speakers from the 60's

and

70's


seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality as

round


speakers, THEY WOULD ALL USE 6x9's as this would create a narrower

speaker


with better bass response (in other words, you would have the benefit


of

a


tower speaker (let's say) only 6" wide, yet you would have the bass

making


potential of an 8" speaker). They would jump at the chance to

accomplish


this if they could. But, again, they don't do it for the reasons

I've
already mentioned. What MANY home speaker manufacturers do is keep

the
width VERY small (some 4" and less for tower speakers) yet they are

quite


deep (12 inches or MORE) to accomodate bass drivers mounted on the


sides

of


the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They

would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
legroups.com...



On Sep 10, 8:11 pm, (bob wald) wrote:



ok , just about every connection.

So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and

midrange.












  #74   Report Post  
Posted to rec.audio.car
Matt Ion Matt Ion is offline
external usenet poster
 
Posts: 420
Default polk 6x9

MOSFET wrote:
I agree with Matt that this issue really boils down to common sense. A cone
in the exact same shape as the voice coil will move up and down in a more
linear fashion than a 6X9, especialy if you are talking about a
high-excursion bass speaker cone.


All good points, except for this. As I noted before, the fact that the
cone is a different shape than the voice coil is irrelevant. The
problem is that the surround will be stressed differently around the
perimeter of a non-circular cone, which in turn will affect the shape of
the cone itself, to introduce artifacts. The effect can be mitigated by
good surround design and construction, but the TENDENCY of it to happen
is just simply inherent to the design.

And on the flipside of that, if a 6X9" speaker is playing a much, much
higher frequenies (as I've already mentioned in this thread) I can imagine a
scenario where the 6" distance has gone up and has started it's way back
down while the 9" distance is still going up. Of course we are talking
minutes differences and a high frequncy (where the cone is moving quickly up
and down) for this to occur. BUT IF THIS SCENARIO CAN OCCUR, HOW COULD THAT
NOT CREATE SONIC ARTIFACTS?

If you can explain to me why this scenario would never, ever happen, I might
be willing to concede that oval's are just as good as round speakers.

Come on, if what I described were true, HOW COULD THAT NOT efffect the sound
in subtle ways (loss of focus, muddied soundstage and imaging)?

Do I have first hand experiece with this? Well, I've used a lot of 6X9's in
my day but they have ALWAYS been for rear-fill in a car. I have never
criticaly listened to home speakers with oval drivers. So I'm going to be
careful here and not state as absolute fact something I have never heard
with my own ears.

But my gut tells me that round speakers are superior because they match the
shape of the voice coil (there is a symetry and logic to this). Oval
speakers DO NOT and therefore have a set of problems round speakers do not
have.

Look, my mind is open. I am no EE or engineer of any type, just a hobyist.
If you can tell me why these issues would not come into play in a home
speaker comprised of ovals, I'm all ears.

MOSFET

"John Durbin" wrote in message
...
Fine, except that it does still not prove your original primary point
that the round driver is inherently better. My point is that as in most
things audio, it's how you execute the design that makes most of the
difference. Not that there aren't totally useless approaches to audio
that result in some mutant products, there probably are... but oval
speakers fall outside that category & have been proven to work just fine
when used intelligently.

It may come across as nitpicking but when you express any opinion around
here - particularly in the form of an absolute - and then use heavily
flawed statements of fact to bolster it, you're probably going to draw a
rebuttal (if anyone's paying attention that knows better, anyway).

Which takes us back to the original question of whether oval speakers
are inherently bad, more specifically 6x9 vs. 6.5 inch drivers. I
maintain that neither you or anyone else here has produced any
legitimate case for that so far. In fact, the one person that did have
anything factual or useful to contribute produced some evidence in favor
of the typically higher sensitivity for the larger cone driver.

I'm NOT trying to say the 6x9 is necessarily better, don't get me wrong.
But if it isn't, it'll more likely be because the design of a particular
example was compromised somewhere along the way for reasons of cost,
manufacturability, stupid input from sales or marketing, poor
engineering work, or any of the other myriad of reasons that often
handicap the final product than because the oval shape made it
impossible to execute properly.

JD

MOSFET wrote:

You know, John, as is ALWAYS the case in the GRAND TRADION OF RAC,
NITPICKING if you use absolutes in this group will ALMOST ALWAYS (see

how I
caught myself there) lead to someone who has an example that rebutts it.

I SHOULD NOT have said "NO" speaker makers use the oval speaker in their
designs. You got me. I reviewed my past posts and, INDEED, I did say

that.
So yes, I am guilty of being inconsistant. Shoot me. My bad.

I can HONESTLY say that when I wrote that I was thinking about the

industry
IN GENERAL though I did not say it. I actually REMEMBER some home

speakers
that did use ovals.

BUT, when you compare number of round cone speakers out there vs. number

of
oval cone speakers out there (in the home speaker market), the oval

speaker
comprises such an incredibly small percentage of the market that I felt
saying the industry "did not use them" was justified.

MOSFET


"John Durbin" wrote in message
...

You were trying to use your perceived absence of oval speakers in "high
end" home speakers to bolster your case that they don't work as well as
round ones. I gave you two specific examples of expensive home speakers
from the past that did use oval speakers. I didn't say everyone used
them, just rebutted your claim that nobody does. Now you want to change
your argument to say MOST instead of NOBODY... I would say that proves
my point.

As to quoting what you found in one Best Buy store as some sort of
reference for what exists in the world of home speakers, give me a

break.
Here's a few current examples:

http://www.koiaudio.com/Main/SD63HK_3.html



http://reviews.cnet.com/surround-spe...-30790670.html
http://yhst-9301186439366.stores.yah...25hisisus.html

http://blog.audiovideointeriors.com/907burmced/

Here's one with an oval passive radiator, which is also fairly common:

http://www.stereophile.com/floorloudspeakers/1105thiel/

More oval woofers:

http://www.hedmag.com/Product-Review...m-No-Place.asp


JD


MOSFET wrote:


Look, I'm sure you're right and that THERE ARE home speakers that
utilize

oval speakers. But look at MOST of the speakers out there that use
pistonic

priciples to produce sound (i.e. cones), the cones are round to match
the

voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the
shape

of the voice coil for PERFECT pistonic linierity.

I was at Best Buy yesterday and the VERY MOST EXPENSIVE ($2,000)

speaker
they sold was a tower Vienna Accousitcs speaker that was 4" wide!!!!!
Tweeter difraction IS VERY REAL and the top speaker makers of this

world
KNOW THIS.

BTW, I didn't see any oval speakers at Best Buy and Magnolia Hi-Fi the
last

time I was there which was within the last couple months (these are two
large retail chains that carry what would be considered low to mid

range
speaker brands). What I DID FIND were tower speakers that nearly

always
tended to be narrow and deep in an attempt to reduce diffraction.

My only point is that oval speakers would be ALL OVER THE PLACE when it
comes to home speakers if there were no sonic drawbacks to them (or at
least

compared to their round bretheren). As you mentioned, these drawbacks
become more pronounced the higher in frequency you go. But you
generally

don't even see ovals being used as bass drivers in home speakers. YOU
JUST

DON'T SEE THEM.

Now I don't know where you shop that you see all these home speakers
utilizing oval speakers. I am actually curious what that smells like.
Do

you have a brand or model in mind that I can find to see this? I AM

NOT
trying to challenge you or calling you a liar, I am TRULY curious. As

I
said before, on the surface, ovals would be IDEAL in designing the most
narrow speaker you can yet still wanting good bass response.

Again, the fact that MOST home speaker makers NEVER use ovals speaks
volumes. I'm sure there is always an exception, but again, just using
common sense, you want a cone whose shape matches the voice coil for

the
BEST linear pistonic movement.

MOSFET

"John Durbin" wrote in message
...


That's simply not true... there have been plenty of home speakers that
used oval cone drivers. Some of the Tandberg teak cabinet models have
them, and I remember a fairly high-end system from Jantzen (spelling?)
that had electrostatics up top and a white oval woofer in the lower
section. That one was someone ahead of its time in that they were
slender towers similar to what people are using for front surrounds
these days, in an era where a floorstanding speaker was more lilely to
be 18" wide and equally deep. At any rate, the shape of the oval

woofer
made it a lot easier to get more bass from the system without having

to
make it a wider cabinet, just as you theorized below. You may not be
familiar with any home speakers with oval components but they

absolutely
exist. I'm sure some basic research on the web would find dozens more
examples.

Frankly, provided the piston is adequately rigid it doesn't matter all
that much what shape it is, up to a point. Certainly lower frequencies
are not affected at all provided the moving element acts in purely
pistonic mode with no gross deflections. Also less symmetrical cones

can
be easier to eliminate standing wave distortions on the cone surface,
which can improve accuracy. The technology to control those kinds of
things during driver design through use of tools like finite element
analysis is light-years ahead of where it was when oval drivers were

the
mainstay of automotive applications.

You should not use a typical automotive 6x9 as the basis for making
these extrapolated statements. They are generally designed for

improved
efficiency & exaggerated midbass output as those are useful in the
average 6x9 application. A component 6.5" driver could have the same
attributes if the designer wanted but would be at an efficiency
disadvantage vs. the 6x9 due to less swept area. You can make that up
with excursion of course but usually that has its own implications in
terms of other non-linear distortions & also added cost. At any rate,
the point is the shape of the cone itself isn't inherently good or

bad,
it's more what you do with that shape as part of the overall driver
design.


As to the flush-mounted tweeter on a large flat baffle, a

well-executed
design in that form factor can perform very well if the baffle effect

is
taken into account when designing the drivers, crossovers etc. You

would
have to spend a bunch of money for a slender tower design that will
outperform my JBL L150A's in any appreciable way.

JD

MOSFET wrote:


I felt I should add one point. I mentioned several times that home
speaker


makers do not use the 6x9" size. This is significant and it
demontrates

that those who design home speakers know the 6X9" has drawbacks that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow (as
narrow


AS POSSIBLE) in an attempt to reduce difraction effects of the

tweeter
(it


muddies your trebble, effects imaging, staging, ect). Some speaker
makers


try to get around this by building small pods around the tweeter, OR
putting


the tweeter all by itself on the top of the speaker, OR just

extending
the


tweeter out a certain distance. What you WANT to try and avoid at

all
costs


is a tweeter mounted flush to a large baffle (something,

unfortunately,
that


was NOT put into practice until the 80's as speakers from the 60's

and
70's


seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality as
round


speakers, THEY WOULD ALL USE 6x9's as this would create a narrower
speaker


with better bass response (in other words, you would have the benefit
of

a


tower speaker (let's say) only 6" wide, yet you would have the bass
making


potential of an 8" speaker). They would jump at the chance to
accomplish


this if they could. But, again, they don't do it for the reasons

I've
already mentioned. What MANY home speaker manufacturers do is keep

the
width VERY small (some 4" and less for tower speakers) yet they are
quite


deep (12 inches or MORE) to accomodate bass drivers mounted on the
sides

of


the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They

would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
ups.com...



On Sep 10, 8:11 pm, (bob wald) wrote:



ok , just about every connection.
So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and

midrange.







  #75   Report Post  
Posted to rec.audio.car
MOSFET MOSFET is offline
external usenet poster
 
Posts: 810
Default polk 6x9

All good points, except for this. As I noted before, the fact that the
cone is a different shape than the voice coil is irrelevant. The
problem is that the surround will be stressed differently around the
perimeter of a non-circular cone, which in turn will affect the shape of
the cone itself, to introduce artifacts. The effect can be mitigated by
good surround design and construction, but the TENDENCY of it to happen
is just simply inherent to the design.


Interesting pointm, Matt. I believe you've mentioned this before but I
forgot about this particular phenomena with oval cones. I can certainly see
your argument is a sound one (no pun intended).

MOSFET


And on the flipside of that, if a 6X9" speaker is playing a much, much
higher frequenies (as I've already mentioned in this thread) I can

imagine a
scenario where the 6" distance has gone up and has started it's way back
down while the 9" distance is still going up. Of course we are talking
minutes differences and a high frequncy (where the cone is moving

quickly up
and down) for this to occur. BUT IF THIS SCENARIO CAN OCCUR, HOW COULD

THAT
NOT CREATE SONIC ARTIFACTS?

If you can explain to me why this scenario would never, ever happen, I

might
be willing to concede that oval's are just as good as round speakers.

Come on, if what I described were true, HOW COULD THAT NOT efffect the

sound
in subtle ways (loss of focus, muddied soundstage and imaging)?

Do I have first hand experiece with this? Well, I've used a lot of

6X9's in
my day but they have ALWAYS been for rear-fill in a car. I have never
criticaly listened to home speakers with oval drivers. So I'm going to

be
careful here and not state as absolute fact something I have never heard
with my own ears.

But my gut tells me that round speakers are superior because they match

the
shape of the voice coil (there is a symetry and logic to this). Oval
speakers DO NOT and therefore have a set of problems round speakers do

not
have.

Look, my mind is open. I am no EE or engineer of any type, just a

hobyist.
If you can tell me why these issues would not come into play in a home
speaker comprised of ovals, I'm all ears.

MOSFET

"John Durbin" wrote in message
...
Fine, except that it does still not prove your original primary point
that the round driver is inherently better. My point is that as in most
things audio, it's how you execute the design that makes most of the
difference. Not that there aren't totally useless approaches to audio
that result in some mutant products, there probably are... but oval
speakers fall outside that category & have been proven to work just

fine
when used intelligently.

It may come across as nitpicking but when you express any opinion

around
here - particularly in the form of an absolute - and then use heavily
flawed statements of fact to bolster it, you're probably going to draw

a
rebuttal (if anyone's paying attention that knows better, anyway).

Which takes us back to the original question of whether oval speakers
are inherently bad, more specifically 6x9 vs. 6.5 inch drivers. I
maintain that neither you or anyone else here has produced any
legitimate case for that so far. In fact, the one person that did have
anything factual or useful to contribute produced some evidence in

favor
of the typically higher sensitivity for the larger cone driver.

I'm NOT trying to say the 6x9 is necessarily better, don't get me

wrong.
But if it isn't, it'll more likely be because the design of a

particular
example was compromised somewhere along the way for reasons of cost,
manufacturability, stupid input from sales or marketing, poor
engineering work, or any of the other myriad of reasons that often
handicap the final product than because the oval shape made it
impossible to execute properly.

JD

MOSFET wrote:

You know, John, as is ALWAYS the case in the GRAND TRADION OF RAC,
NITPICKING if you use absolutes in this group will ALMOST ALWAYS (see

how I
caught myself there) lead to someone who has an example that rebutts

it.

I SHOULD NOT have said "NO" speaker makers use the oval speaker in

their
designs. You got me. I reviewed my past posts and, INDEED, I did say

that.
So yes, I am guilty of being inconsistant. Shoot me. My bad.

I can HONESTLY say that when I wrote that I was thinking about the

industry
IN GENERAL though I did not say it. I actually REMEMBER some home

speakers
that did use ovals.

BUT, when you compare number of round cone speakers out there vs.

number
of
oval cone speakers out there (in the home speaker market), the oval

speaker
comprises such an incredibly small percentage of the market that I

felt
saying the industry "did not use them" was justified.

MOSFET


"John Durbin" wrote in message
...

You were trying to use your perceived absence of oval speakers in

"high
end" home speakers to bolster your case that they don't work as well

as
round ones. I gave you two specific examples of expensive home

speakers
from the past that did use oval speakers. I didn't say everyone used
them, just rebutted your claim that nobody does. Now you want to

change
your argument to say MOST instead of NOBODY... I would say that

proves
my point.

As to quoting what you found in one Best Buy store as some sort of
reference for what exists in the world of home speakers, give me a

break.
Here's a few current examples:

http://www.koiaudio.com/Main/SD63HK_3.html




http://reviews.cnet.com/surround-spe...-30790670.html
http://yhst-9301186439366.stores.yah...25hisisus.html

http://blog.audiovideointeriors.com/907burmced/

Here's one with an oval passive radiator, which is also fairly

common:

http://www.stereophile.com/floorloudspeakers/1105thiel/

More oval woofers:

http://www.hedmag.com/Product-Review...m-No-Place.asp


JD


MOSFET wrote:


Look, I'm sure you're right and that THERE ARE home speakers that
utilize

oval speakers. But look at MOST of the speakers out there that use
pistonic

priciples to produce sound (i.e. cones), the cones are round to

match
the

voice coil, which is ALSO round.

To me it's common sense. OF COURSE you want a cone that matches the
shape

of the voice coil for PERFECT pistonic linierity.

I was at Best Buy yesterday and the VERY MOST EXPENSIVE ($2,000)

speaker
they sold was a tower Vienna Accousitcs speaker that was 4"

wide!!!!!
Tweeter difraction IS VERY REAL and the top speaker makers of this

world
KNOW THIS.

BTW, I didn't see any oval speakers at Best Buy and Magnolia Hi-Fi

the
last

time I was there which was within the last couple months (these are

two
large retail chains that carry what would be considered low to mid

range
speaker brands). What I DID FIND were tower speakers that nearly

always
tended to be narrow and deep in an attempt to reduce diffraction.

My only point is that oval speakers would be ALL OVER THE PLACE when

it
comes to home speakers if there were no sonic drawbacks to them (or

at
least

compared to their round bretheren). As you mentioned, these

drawbacks
become more pronounced the higher in frequency you go. But you
generally

don't even see ovals being used as bass drivers in home speakers.

YOU
JUST

DON'T SEE THEM.

Now I don't know where you shop that you see all these home speakers
utilizing oval speakers. I am actually curious what that smells

like.
Do

you have a brand or model in mind that I can find to see this? I AM

NOT
trying to challenge you or calling you a liar, I am TRULY curious.

As
I
said before, on the surface, ovals would be IDEAL in designing the

most
narrow speaker you can yet still wanting good bass response.

Again, the fact that MOST home speaker makers NEVER use ovals speaks
volumes. I'm sure there is always an exception, but again, just

using
common sense, you want a cone whose shape matches the voice coil for

the
BEST linear pistonic movement.

MOSFET

"John Durbin" wrote in message
...


That's simply not true... there have been plenty of home speakers

that
used oval cone drivers. Some of the Tandberg teak cabinet models

have
them, and I remember a fairly high-end system from Jantzen

(spelling?)
that had electrostatics up top and a white oval woofer in the lower
section. That one was someone ahead of its time in that they were
slender towers similar to what people are using for front surrounds
these days, in an era where a floorstanding speaker was more lilely

to
be 18" wide and equally deep. At any rate, the shape of the oval

woofer
made it a lot easier to get more bass from the system without

having
to
make it a wider cabinet, just as you theorized below. You may not

be
familiar with any home speakers with oval components but they

absolutely
exist. I'm sure some basic research on the web would find dozens

more
examples.

Frankly, provided the piston is adequately rigid it doesn't matter

all
that much what shape it is, up to a point. Certainly lower

frequencies
are not affected at all provided the moving element acts in purely
pistonic mode with no gross deflections. Also less symmetrical

cones
can
be easier to eliminate standing wave distortions on the cone

surface,
which can improve accuracy. The technology to control those kinds

of
things during driver design through use of tools like finite

element
analysis is light-years ahead of where it was when oval drivers

were
the
mainstay of automotive applications.

You should not use a typical automotive 6x9 as the basis for making
these extrapolated statements. They are generally designed for

improved
efficiency & exaggerated midbass output as those are useful in the
average 6x9 application. A component 6.5" driver could have the

same
attributes if the designer wanted but would be at an efficiency
disadvantage vs. the 6x9 due to less swept area. You can make that

up
with excursion of course but usually that has its own implications

in
terms of other non-linear distortions & also added cost. At any

rate,
the point is the shape of the cone itself isn't inherently good or

bad,
it's more what you do with that shape as part of the overall driver
design.


As to the flush-mounted tweeter on a large flat baffle, a

well-executed
design in that form factor can perform very well if the baffle

effect
is
taken into account when designing the drivers, crossovers etc. You

would
have to spend a bunch of money for a slender tower design that will
outperform my JBL L150A's in any appreciable way.

JD

MOSFET wrote:


I felt I should add one point. I mentioned several times that

home
speaker


makers do not use the 6x9" size. This is significant and it
demontrates

that those who design home speakers know the 6X9" has drawbacks

that
compromise sound quality. Why?

Because most mid to high-end home speakers tend to be very narrow

(as
narrow


AS POSSIBLE) in an attempt to reduce difraction effects of the

tweeter
(it


muddies your trebble, effects imaging, staging, ect). Some

speaker
makers


try to get around this by building small pods around the tweeter,

OR
putting


the tweeter all by itself on the top of the speaker, OR just

extending
the


tweeter out a certain distance. What you WANT to try and avoid at

all
costs


is a tweeter mounted flush to a large baffle (something,

unfortunately,
that


was NOT put into practice until the 80's as speakers from the 60's

and
70's


seem to do EXACTLY that).

The point here is that if 6X9's were just as good at sound quality

as
round


speakers, THEY WOULD ALL USE 6x9's as this would create a narrower
speaker


with better bass response (in other words, you would have the

benefit
of

a


tower speaker (let's say) only 6" wide, yet you would have the

bass
making


potential of an 8" speaker). They would jump at the chance to
accomplish


this if they could. But, again, they don't do it for the reasons

I've
already mentioned. What MANY home speaker manufacturers do is

keep
the
width VERY small (some 4" and less for tower speakers) yet they

are
quite


deep (12 inches or MORE) to accomodate bass drivers mounted on the
sides

of


the speakers (you can get away with this because bass tends to be
omnidiriectional).

Anyway, I wanted to clarify my point about home speakers and the
SIGNIFICANCE of the fact they tend to ONLY use round cones. They

would
ALMOST CERTAINLY use the 6X9" if the sound wasn't compromised.

MOSFET
wrote in message
ups.com...



On Sep 10, 8:11 pm, (bob wald) wrote:



ok , just about every connection.
So i was skimming through the posts and noticed that someone had
mentioned that 6.5's are better sounding quality than 6x9's. I

would
like to know why this is. As i was thinking about installing some
6x9's in a friends car with boxes to help out with bass and

midrange.











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Default polk 6x9

this is the stupidest decussion i ever saw.
look if it sounds good it works...the end.
if polk makes it its good......infinity too.
2 of the elite speaker makers on earth.

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bob wald wrote:
this is the stupidest decussion i ever saw.
look if it sounds good it works...the end.
if polk makes it its good......infinity too.
2 of the elite speaker makers on earth.


What about JVC???
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MOSFET wrote:
All good points, except for this. As I noted before, the fact that the
cone is a different shape than the voice coil is irrelevant. The
problem is that the surround will be stressed differently around the
perimeter of a non-circular cone, which in turn will affect the shape of
the cone itself, to introduce artifacts. The effect can be mitigated by
good surround design and construction, but the TENDENCY of it to happen
is just simply inherent to the design.


Interesting pointm, Matt. I believe you've mentioned this before but I
forgot about this particular phenomena with oval cones. I can certainly see
your argument is a sound one (no pun intended).


Really, it just comes back to common sense. Imagine the speaker without
a surround, just the cone attached to the voice coil. You could make
the cone just about any shape you want without really affecting the
sound - square, octagonal, cut out like Big Bird's head. Granted, there
will be some detrimental effect if it's significantly unbalanced
(inertia is a bitch), but as long as it's a symmetrical, centered shape,
the voice coil really won't see the difference just because the cone is
a different shape.

A cheap, under-designed surround, however, will not stretch the same at
all points on a non-circular cone. As an extreme example, imagine a
perfectly square cone (which I guess would be a pyramid, technically),
where not even the corners are rounded. If you use a non-interrupted
surround, ie. one that's fully attached to both cone and basket all the
way around, you can imagine how the surround on the corners would
stretch compared to the rest of it. Once you hit the limits of the
surround itself, it would start bending the corners of the cone down.

Obviously, the effect would not be so pronounced on an oval cone, and
the closer you get to an actual circle, the less pronounced it is, but
you see where the problem comes from. Engineering a better surround, as
I say, will mitigate the effect, but again, this is just a tendency
that's inherent to the design.
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John Durbin wrote:
If you think speaker design does not allow a non-circular surround to be
linear, you really do not know crap about speaker design. Please do
yourselves a favor and pick up a copy of one of the two books I
mentioned in my other post, and get some education.


I never said non-circular design doesn't allow linearity, I said it
makes the design and construction more complex, and poor designs are
more likely to have problems.

I'd point you at a very skilled speaker designer I've known for many
years that could give you chapter & verse why you're both full of crap
but I'm pretty sure he would shoot me for making the introduction. Life
is too short to spend it arguing with other people's guts - it's rarely
successful, and it stinks up the neighborhood.


Whatever. You need to get yourself an education as well - English
comprehension to begin with.


Matt Ion wrote:

MOSFET wrote:

All good points, except for this. As I noted before, the fact that the
cone is a different shape than the voice coil is irrelevant. The
problem is that the surround will be stressed differently around the
perimeter of a non-circular cone, which in turn will affect the
shape of
the cone itself, to introduce artifacts. The effect can be
mitigated by
good surround design and construction, but the TENDENCY of it to happen
is just simply inherent to the design.


Interesting pointm, Matt. I believe you've mentioned this before but I
forgot about this particular phenomena with oval cones. I can
certainly see
your argument is a sound one (no pun intended).



Really, it just comes back to common sense. Imagine the speaker
without a surround, just the cone attached to the voice coil. You
could make the cone just about any shape you want without really
affecting the sound - square, octagonal, cut out like Big Bird's
head. Granted, there will be some detrimental effect if it's
significantly unbalanced (inertia is a bitch), but as long as it's a
symmetrical, centered shape, the voice coil really won't see the
difference just because the cone is a different shape.

A cheap, under-designed surround, however, will not stretch the same
at all points on a non-circular cone. As an extreme example, imagine
a perfectly square cone (which I guess would be a pyramid,
technically), where not even the corners are rounded. If you use a
non-interrupted surround, ie. one that's fully attached to both cone
and basket all the way around, you can imagine how the surround on the
corners would stretch compared to the rest of it. Once you hit the
limits of the surround itself, it would start bending the corners of
the cone down.

Obviously, the effect would not be so pronounced on an oval cone, and
the closer you get to an actual circle, the less pronounced it is, but
you see where the problem comes from. Engineering a better surround,
as I say, will mitigate the effect, but again, this is just a tendency
that's inherent to the design.


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Well, I do concede that the theory of :what seems :"logical" is a poor one
to use in proving my case. So you got me there....

AND, as I stated in my earlier post I DO NOT have first hand knowledge of
what an oval speaker would sound like in the home. So again, you got me
there.

I guess a lot of what I say comes from over 10 years of being on RAC, going
to competions, and subscribing to mags line AS&S, CSR, and CA&E. And, of
course, I have read what others have said about this so I tend to believe
THERE IS "something up"with this issue having heard foks with much more
education and first-hand knowledge than myself.

Perhaps I should not have chimed in as A) I have no personall experience
(though I have used quality aftermarket 6X9's for rear-fill) with ovals
OTHER than in the car where poor accoustics, wind, road, and the engine
produce SO much noise, evaluating SQ of a 6X9 in a car becomes nearly
impossible. B) I am no engineer and therefore I should refrain from talking
about things I have only a cursory knowledge of ( I mean, I DO know a little
like Ohm's law and such). And I REALLY try not to come off as an EE, or
know-it-all. It's just that I DO have a lot of installation experience AND
I worked at Phoenix Gold in their marketinng department (I have an MBA).

Does this make me an expert? No. But I have been into car audio for close
to 20 years now and I feel I have much to offer a newb or someone with a
problem.

But on this subject, since I have NEVER HEARD any artificats coming from a
6X9, I probably should have kept my mouth shut as I was only parroting what
others had said in the past (but again, I lack personnal experience).

MOSFET

Perhaps Matt can chime in with a better working definition of what we are
talking about.


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