[MOSFET]

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.