[mfreak]

You'd also have to define what "equally optimal" means.
You'd also be wrong because you're not saying louder at what frequency.
See the can of worms you've opened up for yourself when you try to make
generalizations like this? :-)

Yess, I see.. My bad for making assumptions, like that ppl would know
I was talking about car subs and not PA gear! Seriously, I DO
understand that there's a ton of 'if' and 'depends on' in my statements
that I didn't specify very well...

How close is "close"? And did you make sure the port was acceptable for
use with your JL subs? Sounds to me like you got really lucky here.

Good question, I know the box volume is almost exactly right. Ports,
no idea.. So I measured my box/ports, and got the specs for the
recomended enclosure from the JL manual. I downloaded WinISD and
entered both. WinISD and the JL manual didn't exactly agree about the
tuning frequency for the recommended box, so IDK what the problem there
is.. Anyway, my box looks to me like it's slightly more SPL oriented,
but fairly close.

http://www.recoilrocks.com/images/subboxes.jpg

The blue line is my box, the magenta one is the recommended. The green
line is something I may be interested in building. Is it worth going
that low, or do you not even really hear those frequencies anyway?
Should I go for a sharper peak at some higher freq, say around 30 Hz,
and let it drop off faster below that? I guess I don't know what the
ideal curve should look like..

I'll probably be starting a new thread with more questions..

[GregS]

In article . com, "mfreak" wrote:
You'd also have to define what "equally optimal" means.
You'd also be wrong because you're not saying louder at what frequency.
See the can of worms you've opened up for yourself when you try to make
generalizations like this? :-)

Yess, I see.. My bad for making assumptions, like that ppl would know
I was talking about car subs and not PA gear! Seriously, I DO
understand that there's a ton of 'if' and 'depends on' in my statements
that I didn't specify very well...

How close is "close"? And did you make sure the port was acceptable for
use with your JL subs? Sounds to me like you got really lucky here.

Good question, I know the box volume is almost exactly right. Ports,
no idea.. So I measured my box/ports, and got the specs for the
recomended enclosure from the JL manual. I downloaded WinISD and
entered both. WinISD and the JL manual didn't exactly agree about the
tuning frequency for the recommended box, so IDK what the problem there
is.. Anyway, my box looks to me like it's slightly more SPL oriented,
but fairly close.

Actually, you can compute all you want, but that does not guarantee
its going to be right. You would assume that the manufacturer specs
are correct. If anyone builds boxes, then some checks should be made.
Other than measuring parameters, one can do a quick check to
see if everything comes out OK. (one should always measure free air
resonance if possible, that will tell you if most of the manufacturers specs are good
in the ballpark)

Basically, the port will minimize cone excursion above the low end frequency
where the port will loose effect. I usually just enter a sine wave tone above
the low end cutoff. Its not very critical. Turn up the volume until
you can see the cone moving. Put your hand near the port, or a port.
The cone excursion should increase. There is usually a big difference in cone
motion. If not, the port may be too long, where the only thing you can do is cut
off part of the port length. I have done this many times, and it includes minor
changes in box size and losses.

greg


http://www.recoilrocks.com/images/subboxes.jpg

The blue line is my box, the magenta one is the recommended. The green
line is something I may be interested in building. Is it worth going
that low, or do you not even really hear those frequencies anyway?
Should I go for a sharper peak at some higher freq, say around 30 Hz,
and let it drop off faster below that? I guess I don't know what the
ideal curve should look like..

I'll probably be starting a new thread with more questions..

[D.Kreft]

mfreak wrote:

Good question, I know the box volume is almost exactly right. Ports,
no idea.. So I measured my box/ports, and got the specs for the
recomended enclosure from the JL manual. I downloaded WinISD and
entered both. WinISD and the JL manual didn't exactly agree about the
tuning frequency for the recommended box, so IDK what the problem there
is..

The problem is that modeling takes guesses--the recommendations that JL
Audio makes are based upon modeling with better software *and* with
lots of experimentation by people with really good ears.

Anyway, my box looks to me like it's slightly more SPL oriented,
but fairly close.

http://www.recoilrocks.com/images/subboxes.jpg

The blue line is my box, the magenta one is the recommended. The green
line is something I may be interested in building. Is it worth going
that low, or do you not even really hear those frequencies anyway?

10ft^3???? Oh my goodness. Yeah, that *might* work for a home setup.

Putting a box with such low extension into a vehicle will very likely
wind up sounding really...."thuddy". Remember that the interior of the
vehicle boosts low frequencies at a rate of roughly 12dB/octave, which
will likely result in a greatly over-exaggerated LF response--great for
reproducing subsonics and giggling your colon; not so great for making
music that doesn't fatigue the brain (and body).

Without actually considering the input power you're supplying, I can't
say whether that would be even safe to do. I don't know what the Vas of
a 10W3 is, but if it's anything less than 10ft^3, then you'd
essentially be making an infinite-baffle setup which can lead you into
mechanical problems. Does WinISD give you the ability to plot excursion
as well as frequency? You should plot that as well. The problem with
ported boxes is that below Fb (in your case, 40 Hz), the subwoofer will
basically unload and play as if it were in "free-air". In other words,
the controlling force that the box exerts on the driver disappears and
the only thing controlling the driver is its suspension--which means
that if you listen to anything with much content below 40Hz, you're
stressin' your driver pretty hard (well, relatively speaking...I don't
recall you saying how much power you were applying to each driver).

Should I go for a sharper peak at some higher freq, say around 30 Hz,
and let it drop off faster below that? I guess I don't know what the
ideal curve should look like..

The "ideal curve"...depends upon what your system goals are and what
kind of music you typically listen to.

If we start getting too deep into this, I'm going to have to punt you
over to JL Audio technical support. I don't have a Reference Manual for
JL Audio's new stuff (I don't even know if I still have my 10-year-old
manual, come to think of it :-) so all I'm going to be able to do is
give you general guidance.

-dan

[GregS]

In article , (GregS) wrote:
In article . com, "mfreak"
wrote:
You'd also have to define what "equally optimal" means.
You'd also be wrong because you're not saying louder at what frequency.
See the can of worms you've opened up for yourself when you try to make
generalizations like this? :-)

Yess, I see.. My bad for making assumptions, like that ppl would know
I was talking about car subs and not PA gear! Seriously, I DO
understand that there's a ton of 'if' and 'depends on' in my statements
that I didn't specify very well...

How close is "close"? And did you make sure the port was acceptable for
use with your JL subs? Sounds to me like you got really lucky here.

Good question, I know the box volume is almost exactly right. Ports,
no idea.. So I measured my box/ports, and got the specs for the
recomended enclosure from the JL manual. I downloaded WinISD and
entered both. WinISD and the JL manual didn't exactly agree about the
tuning frequency for the recommended box, so IDK what the problem there
is.. Anyway, my box looks to me like it's slightly more SPL oriented,
but fairly close.

Actually, you can compute all you want, but that does not guarantee
its going to be right. You would assume that the manufacturer specs
are correct. If anyone builds boxes, then some checks should be made.
Other than measuring parameters, one can do a quick check to
see if everything comes out OK. (one should always measure free air
resonance if possible, that will tell you if most of the manufacturers specs
are good
in the ballpark)

Basically, the port will minimize cone excursion above the low end frequency
where the port will loose effect. I usually just enter a sine wave tone above
the low end cutoff. Its not very critical. Turn up the volume until
you can see the cone moving. Put your hand near the port, or a port.
The cone excursion should increase. There is usually a big difference in cone
motion. If not, the port may be too long, where the only thing you can do is
cut
off part of the port length. I have done this many times, and it includes minor
changes in box size and losses.

I forgot to say, if the cones excursion dimishes when you put your hand near
the port, then the port is too short, or too large in diameter.

greg

[D.Kreft]

GregS wrote:

Other than measuring parameters, one can do a quick check to
see if everything comes out OK. (one should always measure free air
resonance if possible, that will tell you if most of the manufacturers specs are good
in the ballpark)

Maybe it's just my experience having worked with high quality subs for
the entirety of my car audio career, but I for one have never measured
nor even heard of any shop actually doing this...and I've never built a
box to JL's specs that has sounded anything less than stellar. Yes,
there are going to be slight deviations in actual measurements, but I
don't think there's anything worth concerning oneself over to the point
of jumping through all these hoops. We're talking about a lot of extra
tweaking for dubious benefit.

Basically, the port will minimize cone excursion above the low end frequency
where the port will loose effect.

In other words, "the tuning frequency of the port."

I usually just enter a sine wave tone above
the low end cutoff. Its not very critical. Turn up the volume until
you can see the cone moving. Put your hand near the port, or a port.
The cone excursion should increase. There is usually a big difference in cone
motion. If not, the port may be too long, where the only thing you can do is cut
off part of the port length. I have done this many times, and it includes minor
changes in box size and losses.

As long as we're playing around with sine-wave generators (which I
don't suppose many do-it-yourselfers have), it seems to me that a much
simpler approach, without all the hand-waving ( is to simply find the
*actual* Fb and compare that frequency with the frequency you were
attempting to hit with your design. You'll know you've hit the Fb when
cone movement is minimized and there's a hurricane coming out of your
port. If the actual Fb is too high, lengthen the port; if it's too low,
shave a bit off. If you've got enough power, this is also a good way to
see if you need to either do some more rounding of the port edges
(whistling at resonance) or use a larger-diameter port (excessive
huffing).

-dan

[mfreak]

10ft^3???? Oh my goodness. Yeah, that *might* work for a home setup.

The 10 cu ft box is for 2 12's, JL 12w3v2's, so it's actually 5 cu ft
per driver. I'm running 280 rms into each one. The default box WinISD
gave me for 2 12w3v2's was 16 cu ft, which was +- 1 db of linear down
to 19Hz, and tuned to 20.43 Hz! It basically looks the same as the
green line, with the left dropoff shifted left by 10 Hz.

Does WinISD give you the ability to plot excursion
as well as frequency? You should plot that as well.

It does, and I did. Xmax is .51", and I played with the tuning and
size until that box peaked right at the xmax line, at 35 Hz. At freq's
below 20 Hz, it climbs significantly above Xmax again, but less than my
current box, and I haven't blown my subs yet.

http://www.recoilrocks.com/images/conex.jpg

That's after I added on a highpass xover at 20 Hz, which I read was
recommended to curb the high excursion at extremely low freq's.

The "ideal curve"...depends upon what your system goals are and what
kind of music you typically listen to.

Well, as it's been noted, I like it loud, but I guess I'm not sure what
freq's I'm looking for. My current box's SPL peak is about 55Hz
according to WinISD, and freq's below 30 Hz are practically
non-existant. I think it's safe to say I wanna flatten out that 55Hz
peak and move it lower. To where? IDK, 30 Hz? 35? 45? No idea. IDK
how low is just impractical though. I'm willing to give up some SPL for
SQ, but if you can't even hear 20 Hz anyway, no point in building a box
to play 20 Hz well. It's plainly obvious there's a lot more area under
the green SPL curve that the other 2 though. I'm giving up 5db at 55Hz
and gaining 12db at 25.

I'm a metal head. In Flames, Lamb of God, Soilwork, etc.. Double-bass
and a lot of screaming. Sometimes I like hiphop or rap, but mostly
metal. The double bass gives me a nice back massage whenever I'm
driving anywhere!

If we start getting too deep into this, I'm going to have to punt you
over to JL Audio technical support. I don't have a Reference Manual for
JL Audio's new stuff (I don't even know if I still have my 10-year-old
manual, come to think of it :-) so all I'm going to be able to do is
give you general guidance.

That's ok, I'm learning more and more, now you got me on a mission.. A
sheet of mdf doesn't cost THAT much, I suppose I could try a couple
diff. boxes. We'll see how it goes,

[[email protected]]

mfreak wrote:

wrote:
But why are 12's really necessary? I'm sure you know that woofer
diameter is unrelated to frequency extension. It only helps boost the
SPL.

Are you saying that an 8 can hit a low as well as a 12? Totally wrong,
here's a couple quick examples from the mfr's own web sites:

Kicker L7 8" - 28-100 Hz
Kicker L7 12" - 20-100Hz

Pioneer Premier TS-SW841D - 30-1500 Hz
Pioneer Premier TS-SW1241D - 18-1000 Hz

Sure, they hit lower at the same SPL, but graphs just show a fall-off
below +/- 3 dB, not a ledge. You must know it doesn't mean the driver
is incapable of outputting lower bass. Not much music exists below 30
Hz and distortion and road noise gets mistaken for lower frequencies.

Sony MDR-EX71SL headphones only have 9mm drivers but they are rated at
6 Hz to 23000 kHz because they only need to resonate in the ear canal.
Think about cubic feet inside a typical car. Would you install a 12"
subwoofer in a walk-in closet? It's unpleasant unless you keep it
throttled, so why bother? I have no need to brag about my "phat 12s" to
the homeys.

Size DOES appear to be related to freq. response.... As for "It only
helps boost the SPL.", well hell yeah it does! I've had 10's, 12's,
and 15's in the past. The bigger, the louder, AND the lower. If
you're happy at a level of SPL and SQ that 8's can give you, then
that's great! You'll spend a lot less $, and you'll have more room in
your trunk. I personally require more than that.

My point is, there's too much ego bass inflicted on the public and it's
not about sound quality _inside_ the car. It's more like the audio
equivalent of a dog ****ing on a hydrant to mark territory. If you can
run tame 12s, fine, but it gets abused a lot. In my area, big bass is
usually linked with crime. The belligerence of some of these assholes
is astounding.

Brad

[[email protected]]

D.Kreft wrote:

The unfortunate part about this is that we get nothing for free--as you
increase the moving mass of the system, you reduce its efficiency. As
you reduce its efficiency, you must increase power to get the same
output. As you increase power, you drive the speaker to its physical
and thermal limits. To increase the Xmax of the driver to get more
output from the smaller driver at low frequencies, you start running
into practical limitations of conventional loudspeaker design, namely a
great difficulty in designing a suspension that is capable of remaining
somewhat linear throughout a very large travel. And as Xmax increases,
you have to put a bigger and bigger motor on the back of that subwoofer
in order to "wrench" it back and forth so rapidly over so great a
distance--which puts incredible amounts of acceleration on the driver
at the top and bottom of it's stroke. So then you have to re-design
your cone to handle the stress. It's the loudspeaker equivalent of
buying a rice burner (e.g. Honda, Toyota) and trying to make it perform
like a Corvette.

Good explanation of why many larger cones sound "looser." (No, that's
not the usual typo for "loser.")

If you're happy at a level of SPL and SQ that 8's can give you, then
that's great! You'll spend a lot less $, and you'll have more room in
your trunk. I personally require more than that.

I dunno, sir, it sounds to me a bit like you've fallen for the old "mo'
bigga, mo' betta'" wive's tale. I'd be interested to know what
well-designed small-driver systems you've actually tried-out for
yourself. I'm not saying you *haven't* actually experimented with
smaller drivers--just curious--because my experience tells me that
typically, it's a matter of prejudice.

There's tons of ego involved in car stereos, but I do have a 12" sub in
my home system because I'm filling a much bigger volume. What's funny
is that I only need a single 12" driver for a 20x20 ft living room,
while these jokers put banks of them in SUVs with maybe 1/10th the
airspace. That much pressure cannot be good for the inner ear. I just
wish nature would make them go deaf or get tinnitus in time for me to
sleep!

When I was a salesman at Speaker Warehouse in Hollywood, FL, I would go
through this all the time with kids who'd come in and "poo-poo" smaller
drivers because they couldn't "quad" hard enough. So, I'd take them out
to my car and ask them to sit and listen for a little bit. I'd then
turn the stereo down and ask them what they thought they were listening
to in terms of driver size, number and amp power. I'd typically get
responses like "500W and a pair of 12-inch subs" or something crazy
like that. Then I'd take them around, open the hatch and show them a
single 10" in a single-reflex bandpass powered by half of a 50x4. There
wasn't one person to whom I showed my car that wasn't floored.

And of course most music (except for synthesized bass) rarely goes
below 30 Hz or even 40 Hz. Bigger cones are just flapping around
wasting energy in many cases.

Brad

[[email protected]]

D.Kreft wrote:

The unfortunate part about this is that we get nothing for free--as you
increase the moving mass of the system, you reduce its efficiency. As
you reduce its efficiency, you must increase power to get the same
output. As you increase power, you drive the speaker to its physical
and thermal limits. To increase the Xmax of the driver to get more
output from the smaller driver at low frequencies, you start running
into practical limitations of conventional loudspeaker design, namely a
great difficulty in designing a suspension that is capable of remaining
somewhat linear throughout a very large travel. And as Xmax increases,
you have to put a bigger and bigger motor on the back of that subwoofer
in order to "wrench" it back and forth so rapidly over so great a
distance--which puts incredible amounts of acceleration on the driver
at the top and bottom of it's stroke. So then you have to re-design
your cone to handle the stress. It's the loudspeaker equivalent of
buying a rice burner (e.g. Honda, Toyota) and trying to make it perform
like a Corvette.

Good explanation of why many larger cones sound "looser." No, that's
not the usual typo for "loser."

If you're happy at a level of SPL and SQ that 8's can give you, then
that's great! You'll spend a lot less $, and you'll have more room in
your trunk. I personally require more than that.

I dunno, sir, it sounds to me a bit like you've fallen for the old "mo'
bigga, mo' betta'" wive's tale. I'd be interested to know what
well-designed small-driver systems you've actually tried-out for
yourself. I'm not saying you *haven't* actually experimented with
smaller drivers--just curious--because my experience tells me that
typically, it's a matter of prejudice.

There's tons of ego involved in car stereos, but I do have a 12" sub in
my home system because I'm filling a much bigger volume. What's funny
is that I only need a single 12" driver for a 20x20 ft living room,
while these jokers put banks of them in SUVs with maybe 1/10th the
airspace. That much pressure cannot be good for the inner ear. I just
wish nature would make them go deaf or get tinnitus in time for me to
sleep!

When I was a salesman at Speaker Warehouse in Hollywood, FL, I would go
through this all the time with kids who'd come in and "poo-poo" smaller
drivers because they couldn't "quad" hard enough. So, I'd take them out
to my car and ask them to sit and listen for a little bit. I'd then
turn the stereo down and ask them what they thought they were listening
to in terms of driver size, number and amp power. I'd typically get
responses like "500W and a pair of 12-inch subs" or something crazy
like that. Then I'd take them around, open the hatch and show them a
single 10" in a single-reflex bandpass powered by half of a 50x4. There
wasn't one person to whom I showed my car that wasn't floored.

And of course most music (except for synthesized bass) rarely goes
below 30 Hz or even 40 Hz. Bigger cones are just flapping around
wasting energy in many cases.

Brad

[[email protected]]

mfreak wrote:

As for "It only
helps boost the SPL.", well hell yeah it does! I've had 10's, 12's,
and 15's in the past. The bigger, the louder, AND the lower.

Not if you put them all in the same-sized box. Remember...it's
positively meaningless to compare drivers outside of their enclosures.
Absolutely meaningless. So don't do it--it sounds silly when you do.

You're right, and I agree with pretty much everything you said,
including the above statement.. However, people don't put 8's and 12's
in the same size box.. Even most dummies could tell you larger subs go
in larger boxes.

But the "box" is ultimately the car's interior volume, assuming the
woofer is properly mounted. If you compare the typical boom-car set up
to what people install in homes, it's extreme overkill at the low end.
You can tell when someone's critically listening or just broadcasting.

The smallest sub box I ever personally tried was a single 10. And I
wasn't impressed.. I had a dual 10 box after that, it was ok, better,
but nothing close to what I have now.. I've never seen anyone with a
single 10 OR a dual 10 that compares to what I have. But my experience
is limited, so idk..

But how loud are you playing it? Just being louder than the next guy
has little to do with music quality. This country has a big ThugWoofer
problem. You may be a decent guy but you could be angering people and
not knowing it. Many victims don't complain because they fear criminal
retaliation. ThugBass comes off like beating war drums or doing a Haka.
Challenge back the average bass-head and you get a lot of belligerence.
They are already aware that it bothers people but they choose to keep
doing it.

Brad

[[email protected]]

flak_monkey wrote:

The jackhammer is a pile of crap. A really heavy pile of loud,
obnoxious, distortion-making crap.
People who want it are children with little peckers who think that
louder = better sound quality and have never heard a properly tuned
setup, much less ever thought about owning one.

I can't imagine a vehicle big enough to need the JackHammer, except a
Caterpillar 797 dump truck, with the woofer in the bed.

Brad

[GregS]

In article om, "D.Kreft" wrote:
GregS wrote:

Other than measuring parameters, one can do a quick check to
see if everything comes out OK. (one should always measure free air
resonance if possible, that will tell you if most of the manufacturers specs
are good
in the ballpark)

Maybe it's just my experience having worked with high quality subs for
the entirety of my car audio career, but I for one have never measured
nor even heard of any shop actually doing this...and I've never built a
box to JL's specs that has sounded anything less than stellar. Yes,
there are going to be slight deviations in actual measurements, but I
don't think there's anything worth concerning oneself over to the point
of jumping through all these hoops. We're talking about a lot of extra
tweaking for dubious benefit.

Basically, the port will minimize cone excursion above the low end frequency
where the port will loose effect.

In other words, "the tuning frequency of the port."

I usually just enter a sine wave tone above
the low end cutoff. Its not very critical. Turn up the volume until
you can see the cone moving. Put your hand near the port, or a port.
The cone excursion should increase. There is usually a big difference in cone
motion. If not, the port may be too long, where the only thing you can do is
cut
off part of the port length. I have done this many times, and it includes
minor
changes in box size and losses.

As long as we're playing around with sine-wave generators (which I
don't suppose many do-it-yourselfers have), it seems to me that a much
simpler approach, without all the hand-waving ( is to simply find the
*actual* Fb and compare that frequency with the frequency you were
attempting to hit with your design. You'll know you've hit the Fb when
cone movement is minimized and there's a hurricane coming out of your
port. If the actual Fb is too high, lengthen the port; if it's too low,
shave a bit off. If you've got enough power, this is also a good way to
see if you need to either do some more rounding of the port edges
(whistling at resonance) or use a larger-diameter port (excessive
huffing).

There are CD's and you could probably make MP3's with various tones instead
of using a generator. I have test CD's around I have not even had a chance to use.
I have been doing things using generators and such, even measured the parameters
once using the online calculations from.....
http://www.kbapps.com/

But, I have used all kinds of drivers over the years, many cheap, but few expensive.
I also intentionaly alter driver weights sometimes to lower resonant frequency.

I like the idea of using sealed box woofers. It just seems natural to have
a better response match for cars. Perhaps one cannot hear 20 Hz, but
you sure can feel it.

greg

[flak_monkey]

Wrote:
D.Kreft wrote:



And of course most music (except for synthesized bass) rarely goes
below 30 Hz or even 40 Hz. Bigger cones are just flapping around
wasting energy in many cases.

Brad

I'd like to disagree on this point. And what music doesn't have a
synthesizer in it these days? The intro to the Dark Side of The Moon
(breathe) has a good passage of 20-25 hz on it and it's older than I
am. Kick drums can play very low depending on the size, and of course
there is five and six string basses. Drop the tuning a little and you
are down into the upper to mid 20's. And then there are harmonics from
upright basses, the note is the same, but that's only about 70% of the
wave form IIRC. The rest depends on the material and the size of the
instrument. Also, there are organs. My point is that there are plenty
of instruments and synthesized sounds in both today's music and music
of the past that have program material way below 3o to 40 hz. I bet
somebody's already mentioned that bigger cones are TYPICALLY (empahsis
on that) more efficient and require less power to obtain a given sound
pressure level, even at low frequencies. Your statement that they are
flapping around and wasting energy is incorrect. If it were true, then
I wouldn't need a gigantic 15 to 18 inch woofer to gig with and play my
six string bass on, I could just use a single ten. They are actually, in
a general sense, more efficient and conserving energy. You seem to have
a general misunderstanding of how size and material effect many of the
parameters of a driver.


--
flak_monkey

[MOSFET]

Yes, Dan, you're right, size of the driver (by itself) has little to do with
frequency response.

Example: Heaphone Speakers - Has anyone mentioned that little paradox yet?
My tiny speakers on my Grado's go down to 25 Hz. Yet they have a diameter
of 2". Obviously other physics besides speaker diameter are at work here.

Also, I remember once an IASCA competitor (Dan, you might know who I'm
talking about) who used a bank of 4" drivers as his "subwoofers". They
apparently were capabale of producing significant output down to 20 Hz (of
course, cabin gain plays a big part here).

MOSFET


"D.Kreft" wrote in message
oups.com...
mfreak wrote:

You're right, and I agree with pretty much everything you said,
including the above statement.. However, people don't put 8's and 12's
in the same size box.. Even most dummies could tell you larger subs go
in larger boxes.

That's also not true. A JL Audio 8W2 (we're talking old-school, here)
worked really well in about 1.75 cubic feet, ported. A JL Audio 12W6
would also work in 1.75 cubic feet, sealed. Granted, the 12W6 wouldn't
be in its optimal box--it prefers an even *smaller* box--1.25, sealed.

If anyone could get a single 10 to sound like my 2 12's, then I can't
even imagine what that same person could make my 12's sound like!

I don't know about *your* 12's, but I've personally listened to JL
Audio subs in SRBP boxes that I or my co-workers have designed that
were just....sick (read: "very loud").

I guess I needed to qualify that with "given equally optimal
enclosures".
Given equally optimal enclosures, the bigger drivers will be louder
and hit lower. I can't possibly be wrong about this?

Yes, you could. :-) Because then I could hand you a 10" E/V loudspeaker
(which is actually a professional midrange) and compare it to a 10"
subwoofer, and the subwoofer would play lower, while the E/V would be
"infinitely" louder.

You'd also have to define what "equally optimal" means.

You'd also be wrong because you're not saying louder at what frequency.
A sealed box has a characteristic roll-off of 12dB/octave below F3,
ported boxes 18dB/octave or higher depending upon the alignment.
Everyone says that ported boxes are more "efficient" but if you look
low enough in the frequency response curve of the ported box (below
F3), you'll find that the output is actually *far* less than that of
the sealed box, even though the sealed box is "less efficient."

It'd also be wrong because professional subs (like the kind you see at
concerts) are more efficient than car audio subs, so it's not even fair
there.

See the can of worms you've opened up for yourself when you try to make
generalizations like this? :-)

The smallest sub box I ever personally tried was a single 10. And I
wasn't impressed.. I had a dual 10 box after that, it was ok, better,
but nothing close to what I have now.. I've never seen anyone with a
single 10 OR a dual 10 that compares to what I have. But my experience
is limited, so idk..

You could have saved me a bunch of typing by qualifying this up front.
;-)
When you speak from limited experience, it's usually best for all
concerned to humbly state that up front so people know how to weigh
your comments. No harm has been done, but it's just a good idea in
general to be forthcoming with these little details. :-)

When I had the 2 10's, an install shop quoted me something like $250 to
build a custom enclosure. Hell, that cost more than the subs
themselves! MAYBE it woulda been worth it, but I didn't beleive it
would be at the time, based on other systems with 10's that I'd heard.

I couldn't comment on the enclosure or the price unless I knew what
they planned to build. If it were a bandpass enclosure, then yeah, I
can see $250. If it had a bunch of angles or involved any amount of
fiberglass work, then yeah, I can see that. If it was a simple
plain-Jane ported or sealed box, then I'd want to know what material
they were using to make the box. :-)

I dont build boxes, I guess I'm afraid I'd waste hours and hours trying
to build the perfect enclosure, then not even be able to notice the
difference. That's assuming I could obtain plans for this perfect
enclosure.

Well, you see, that's why some people get paid to do this. If you
already have the drivers, contact your dealer for the optimal box
configuration for you (e.g. "A sealed box of X cu.ft. or a ported box
of X cu.ft. and a port that's Y by Z")...but if you're looking for
maximum SPL (requiring a more efficient enclosure like a SRBP), that's
more involved and requires more work--something the manufacturer will
typically draw-up for you for free (I designed *lots* of bandpass
enclosures for people when I served as a Technical Support Specialist
for JL Audio :-).

I just have a pre-fab ported MTX box that came with 2 12's
I bought like 10 years ago. I've upgraded the subs since then. I know
the dimensions of the box are close to what JL says the recommended
enclosure is, and I know it's the loudest, hardest pounding system I've
ever had.

So now you're comparing different *brands* of speakers in addition to
comparing different sizes? Ouch...that's not comparing apples to
oranges, that's like apples and automobiles. :-)

How close is "close"? And did you make sure the port was acceptable for
use with your JL subs? Sounds to me like you got really lucky here.

-dan

[D.Kreft]

MOSFET wrote:

Also, I remember once an IASCA competitor (Dan, you might know who I'm
talking about) who used a bank of 4" drivers as his "subwoofers". They
apparently were capabale of producing significant output down to 20 Hz (of
course, cabin gain plays a big part here).

I don't remember his name, but I think I remember the brand of driver:
G&S. Those things were pretty stinking beefy (my shop used to sell
'em).

-dan

[MOSFET]

And of course most music (except for synthesized bass) rarely goes
below 30 Hz or even 40 Hz. Bigger cones are just flapping around
wasting energy in many cases.

Brad


You are touching on an often discussed topic here. Are smaller subwoofers
(8", 10", 12") "tighter" than larger subwoofers (15", 18", or larger)?

This seems to be an often repeated "true-ism" in the world of car-audio.
You hear car audio sales people say this ALL the time, "you want multiple
smaller woofers as it will sound 'tighter' than larger ones".

I went back forth with someone on this (Matt I think) and what we concluded
was that ALL THINGS BEING EQUAL (this is the key statement) there is no
reason why a larger cone should move any faster, or sound "tighter" than a
smaller cone.

The problem is that seldom are "all things equal".

What you tend to find with in subwoofer manufacturing is that they will
often use the same motor structure in their 15" subwoofer as they will in
their 12" subwoofer, or the same motor in their 18" as their 15" model. OR,
they might put a motor structure on their larger woofers (15" or 18") that
is not in proportion with the cone size of their smaller woofers (the 10's
and 8's). Just look at the back of a bunch of 8" and 10" subwoofers, and
then look at the back of a bunch of 15" and 18" subwoofers. What you will
tend to see is a smaller motor in relation to the cone size with the larger
subwoofers. This tends to be true even with the more "higher-end" brands.
THIS IS THE PROBLEM.

Obviously, this WILL effect performance. Where you find the above to be
true, then yes, the smaller woofers WILL be faster and sound "tighter". But
if the motor structure is kept in proportion to cone size, then no, in
theory there should be no difference.

So did I answer the question? Basically, it depends on the woofer in
question.

But, again, if ALL THINGS ARE KEPT EQUAL, cone diameter DOES NOT effect the
speed or "tightness" of the woofer.

MOSFET

[D.Kreft]

On Oct 11, 6:42 pm, "MOSFET" wrote:

This seems to be an often repeated "true-ism" in the world of car-audio.
You hear car audio sales people say this ALL the time, "you want multiple
smaller woofers as it will sound 'tighter' than larger ones".

Heheh...every time I get into this discussion it takes me back to The
Day.

I took a one-week installation course in Orlando, FL from a place
called Creative Mobile Associates
(I don't think they're around any longer--haven't been in some time).
Every day we had 6 or 8 hours
of class and a test to take. Out of the 5 tests, I got every single
question right....except one:

T / F Smaller subs produce tighter bass than larger subs.

I instinctively circled "T" and wound up getting a 99.34% average
across all my tests. I was one misconception
away from having a perfect score. I argued my case, but was ultimately
unable to persuade my instructor that I was bigger than him and could
hurt him.

It's a lesson I never forgot. :-)

-dan

[Daniel W. Rouse Jr.]

Also, even cheap $20 Koss "The Plug" earplug type headphones will go as low
as 10Hz (at least, that's what is listed in the specs on the package).

They probably aren't more than 1/2 inch in diameter, and yet they do
reproduce very low bass. (Although that type of headphone probably qualifies
as a transducer, rather than a loudspeaker magnet/voicecoil/cone type of
driver design.)


"MOSFET" wrote in message
...
Yes, Dan, you're right, size of the driver (by itself) has little to do
with
frequency response.

Example: Heaphone Speakers - Has anyone mentioned that little paradox yet?
My tiny speakers on my Grado's go down to 25 Hz. Yet they have a diameter
of 2". Obviously other physics besides speaker diameter are at work here.

Also, I remember once an IASCA competitor (Dan, you might know who I'm
talking about) who used a bank of 4" drivers as his "subwoofers". They
apparently were capabale of producing significant output down to 20 Hz (of
course, cabin gain plays a big part here).

MOSFET


"D.Kreft" wrote in message
oups.com...
mfreak wrote:

You're right, and I agree with pretty much everything you said,
including the above statement.. However, people don't put 8's and
12's
in the same size box.. Even most dummies could tell you larger subs
go
in larger boxes.

That's also not true. A JL Audio 8W2 (we're talking old-school, here)
worked really well in about 1.75 cubic feet, ported. A JL Audio 12W6
would also work in 1.75 cubic feet, sealed. Granted, the 12W6 wouldn't
be in its optimal box--it prefers an even *smaller* box--1.25, sealed.

If anyone could get a single 10 to sound like my 2 12's, then I can't
even imagine what that same person could make my 12's sound like!

I don't know about *your* 12's, but I've personally listened to JL
Audio subs in SRBP boxes that I or my co-workers have designed that
were just....sick (read: "very loud").

I guess I needed to qualify that with "given equally optimal
enclosures".
Given equally optimal enclosures, the bigger drivers will be louder
and hit lower. I can't possibly be wrong about this?

Yes, you could. :-) Because then I could hand you a 10" E/V loudspeaker
(which is actually a professional midrange) and compare it to a 10"
subwoofer, and the subwoofer would play lower, while the E/V would be
"infinitely" louder.

You'd also have to define what "equally optimal" means.

You'd also be wrong because you're not saying louder at what frequency.
A sealed box has a characteristic roll-off of 12dB/octave below F3,
ported boxes 18dB/octave or higher depending upon the alignment.
Everyone says that ported boxes are more "efficient" but if you look
low enough in the frequency response curve of the ported box (below
F3), you'll find that the output is actually *far* less than that of
the sealed box, even though the sealed box is "less efficient."

It'd also be wrong because professional subs (like the kind you see at
concerts) are more efficient than car audio subs, so it's not even fair
there.

See the can of worms you've opened up for yourself when you try to make
generalizations like this? :-)

The smallest sub box I ever personally tried was a single 10. And I
wasn't impressed.. I had a dual 10 box after that, it was ok, better,
but nothing close to what I have now.. I've never seen anyone with a
single 10 OR a dual 10 that compares to what I have. But my
experience
is limited, so idk..

You could have saved me a bunch of typing by qualifying this up front.
;-)
When you speak from limited experience, it's usually best for all
concerned to humbly state that up front so people know how to weigh
your comments. No harm has been done, but it's just a good idea in
general to be forthcoming with these little details. :-)

When I had the 2 10's, an install shop quoted me something like $250
to
build a custom enclosure. Hell, that cost more than the subs
themselves! MAYBE it woulda been worth it, but I didn't beleive it
would be at the time, based on other systems with 10's that I'd heard.

I couldn't comment on the enclosure or the price unless I knew what
they planned to build. If it were a bandpass enclosure, then yeah, I
can see $250. If it had a bunch of angles or involved any amount of
fiberglass work, then yeah, I can see that. If it was a simple
plain-Jane ported or sealed box, then I'd want to know what material
they were using to make the box. :-)

I dont build boxes, I guess I'm afraid I'd waste hours and hours
trying
to build the perfect enclosure, then not even be able to notice the
difference. That's assuming I could obtain plans for this perfect
enclosure.

Well, you see, that's why some people get paid to do this. If you
already have the drivers, contact your dealer for the optimal box
configuration for you (e.g. "A sealed box of X cu.ft. or a ported box
of X cu.ft. and a port that's Y by Z")...but if you're looking for
maximum SPL (requiring a more efficient enclosure like a SRBP), that's
more involved and requires more work--something the manufacturer will
typically draw-up for you for free (I designed *lots* of bandpass
enclosures for people when I served as a Technical Support Specialist
for JL Audio :-).

I just have a pre-fab ported MTX box that came with 2 12's
I bought like 10 years ago. I've upgraded the subs since then. I know
the dimensions of the box are close to what JL says the recommended
enclosure is, and I know it's the loudest, hardest pounding system
I've
ever had.

So now you're comparing different *brands* of speakers in addition to
comparing different sizes? Ouch...that's not comparing apples to
oranges, that's like apples and automobiles. :-)

How close is "close"? And did you make sure the port was acceptable for
use with your JL subs? Sounds to me like you got really lucky here.

-dan

[Captain_Howdy]

LOL This reminds me of someone on here that does not have his own car and
thinks he is a Car Audio expert because he buys stereo magazines on Ebay, item
# 9713556467, 9713766820, 9713766361, 9713765514, 9713556088, 9713555566.
He will LIE and he will CRY, we all seen that.

This is just too funny, a hoot in fact.



How to identify a r.a.c newbie.

http://www.teamrocs.com/crap/newbie.htm

[MOSFET]

Oh, you seem to be talking about me, yet again.

Those weren't car stereo magazines you bonehead. They were very old issues
of Audiophile (I'm a collector) which has NOTHING to do with car audio.

Yet, again, you prove what a TOTAL moron you are.

MOSFET

"Captain_Howdy" wrote in message
...
LOL This reminds me of someone on here that does not have his own car and
thinks he is a Car Audio expert because he buys stereo magazines on Ebay,
item
# 9713556467, 9713766820, 9713766361, 9713765514, 9713556088, 9713555566.
He will LIE and he will CRY, we all seen that.

This is just too funny, a hoot in fact.



How to identify a r.a.c newbie.

http://www.teamrocs.com/crap/newbie.htm

[Captain_Howdy]

bbahhhhhhhaaaaaaaa

You're a collector alright

hahahahahahha

I think that you summed up your moron status in the battery charger thread.

heheheheheheheeheheheheheh



In article , "MOSFET"
wrote:
Oh, you seem to be talking about me, yet again.

Those weren't car stereo magazines you bonehead. They were very old issues
of Audiophile (I'm a collector) which has NOTHING to do with car audio.

Yet, again, you prove what a TOTAL moron you are.

MOSFET

"Captain_Howdy" wrote in message
. ..
LOL This reminds me of someone on here that does not have his own car and
thinks he is a Car Audio expert because he buys stereo magazines on Ebay,
item
# 9713556467, 9713766820, 9713766361, 9713765514, 9713556088, 9713555566.
He will LIE and he will CRY, we all seen that.

This is just too funny, a hoot in fact.



How to identify a r.a.c newbie.

http://www.teamrocs.com/crap/newbie.htm

[MOSFET]

"Captain_Howdy" wrote in message
...

bbahhhhhhhaaaaaaaa

You're a collector alright

hahahahahahha

I think that you summed up your moron status in the battery charger
thread.

heheheheheheheeheheheheheh


Yeh, sure Bob (I mean Howdy), whatever you say.

MOSFET

[MOSFET]

And furthermore (this is NOT directed towards Howdy). Why is there anything
wrong with car audio magazines?

I haven't bought one in about 6 years, but LONG ago, they were a key source
of info regarding competitions (IASCA information), how-to info,
test-reports, and so on. Now we have the internet (I'm talking very early
90's) so I personally don't find car audio magazines very useful or relevant
(today they just seem like one big advertisement).

But I do treasure my very old car stereo magazines (I have all the CSR and
CA&E's going back to 1989). It's fun to flip through those old magazines
and marvel at the changes in technology.

The idea that car audio mags= RAC newbie is ridiculous. I am certainly no
newbie here (I have been surfing RAC for over 11 years, worked in the
industry at Phoenix Gold, and competed for years in IASCA). I have been
into car audio for over 22 years now. There is nothing wrong with car
audio mags.

MOSFET

[D.Kreft]

Captain_Howdy wrote:

[...snip...]

Do you have to ruin every thread you "participate" in? Seriously, can't
you just stop with the public mocking and just e-mail Nick privately
and duke it out with him behind the scenes?

I have no problem with joking around and having fun; but this sort of
prolonged, childish harassment is incredibly tiresome.

-dan

[D.Kreft]

MOSFET wrote:

I ... worked in the industry at Phoenix Gold

I didn't know that. What did you do there? How long did you work at PG?
And, if it's not too personal of a question, why did you leave?

-dan

[MOSFET]

I worked in the marketing dept. (I have an MBA from the University of
Portland) from 2000-2001, Keith Peterson hired me.

At that time, I was also a college professor at the University of Portland.
I taught an evening class on Consumer Behavior to both graduates and
undergrads.

Before that, I had worked 10 years as an executive at AT&T.

I was forced to quit both jobs and move back to my home town of Stanwood,
Washington in late 2001 because my father had a heart attack and I was
needed to help run my family's company, Tanner Properties. We own office
buildings, apartment complexes, rental houses, etc.

That is what I still do today and to be totally honest, I don't miss the
"rat-race" AT ALL. I like being 'the boss" and living in my home town suits
my wife and I just fine.

Furthermore, with the sale of Phoenix Gold and Keith no longer at the helm,
I'm not sure I would have still wanted to work there.

Nicholas Tanner aka
MOSFET




"D.Kreft" wrote in message
oups.com...
MOSFET wrote:

I ... worked in the industry at Phoenix Gold

I didn't know that. What did you do there? How long did you work at PG?
And, if it's not too personal of a question, why did you leave?

-dan

[[email protected]]

MOSFET wrote:

What you tend to find with in subwoofer manufacturing is that they will
often use the same motor structure in their 15" subwoofer as they will in
their 12" subwoofer, or the same motor in their 18" as their 15" model. OR,
they might put a motor structure on their larger woofers (15" or 18") that
is not in proportion with the cone size of their smaller woofers (the 10's
and 8's). Just look at the back of a bunch of 8" and 10" subwoofers, and
then look at the back of a bunch of 15" and 18" subwoofers. What you will
tend to see is a smaller motor in relation to the cone size with the larger
subwoofers. This tends to be true even with the more "higher-end" brands.
THIS IS THE PROBLEM.

Obviously, this WILL effect performance. Where you find the above to be
true, then yes, the smaller woofers WILL be faster and sound "tighter". But
if the motor structure is kept in proportion to cone size, then no, in
theory there should be no difference.

Except that there's more potential for cone surface distortion as size
increases. I'm guessing the magnet assembly would have to be much
stronger (non-linear progression) to equally control the mass of a
larger cone. It's like the difference between "punching the air" with a
pocket umbrella vs. a beach umbrella. Not only are you fighting more
air-resistance, there's likely to be more flex over that larger area.

Brad

[[email protected]]

Troy T. wrote:

Brad,

I am sorry about my first comment.I dont know rot13.I just cant stand
people that have their bass ALL the way up so that all you hear is
bass and their car about to rattel apart.
I have seen the Jackhammers installed in a car and they actually ave
this massive metal support bracket to hold it up. Again im sorry

TroyT

No offense taken - but y'all still got dem kissin' periods and jungle
spelling. ;]

Qng EBG13 furrlhg or byq fpubby Hfrarg.

Brad

[[email protected]]

I. Care wrote:

The first time I rode in a "boom car" (mid 90s) I knew it was all for
show. It quickly became unpleasant to listen to and physically annoying
to be around. These fools drive around causing themselves pain and
inflicting it on everyone else. The same mindset makes them endure
low-rider cars with stiff, bumpy rides.

Brad


Generally when asked they also state they are into good music. The
unfortunate part is that in a couple of years, if not already, they
won't be able to hear the very music they claim they enjoy.

What I really think they enjoy, is pi**ing off everyone else around them
or calling attention to themselves, not truly enjoying the music.

ThugBass is an attempt by the "societally-wronged" to even the score.
They be slingin' some powah bak at da oppressors. Too bad they can't
just clean up their own stupid act. Thug lineage goes way back.

Brad

[Eric Desrochers]

Except that there's more potential for cone surface distortion as size
increases.

This kind of distorsion surely won't overwhelm the distorsion produced
by having a larger excursion to compensate for smaller cone. Also, at
subwoofer frequencies the cone mostly keeps its piston behavior ie, no
cone breakup.

--
Eric (Dero) Desrochers
http://homepage.mac.com/dero72

Hiroshima 45, Tchernobyl 86, Windows 95

[Eric Desrochers]

MOSFET wrote:

You are touching on an often discussed topic here.

.... And I wonder why because it's well known everywhere else that there
is no such thing. A good place to start is :

http://www.soundstage.com/maxdb/maxdb061999.htm

Mostly, a subwoofer CANNOT be fast because it is band limited by
definition, by the crossover and/or its own natural response. Any
driver able to reproduce the frequency it is asked to reproduce will be
plenty fast. We want it to reproduce, say, up to 80 Hz? It can
reproduce 80 Hz at full volume? No need to be any faster than this.

What is refered as a fast bass is actually a function of what is
happening in the mid-bass range. A fast, dynamic system will comprise
of good mid-bass in good enclosure and proper crossover settings. For
example, a 12 inches sub crossed over to cheap 5 inches mids will sound
slow and bloated.

Another factor in the thightness of the sound may come from the tuning
of the box. It is generally understood that sealed boxes are more
damped, hence sound thighter and more true. But I think most already
know this!

Regards,

--
Eric (Dero) Desrochers
http://homepage.mac.com/dero72

Hiroshima 45, Tchernobyl 86, Windows 95

[Captain_Howdy]

The whole thing just screams your name, Misfit the junk collector.
What did you do at Phoenix Gold other then sweep the parking lot?
Where are all of your IASCA trophies, did your pet monkey eat them?
You've have been into car audio for over 22 years now and you still don't know
****. That's why you give damaging advice just like your friend Bob.



The idea that car audio mags= RAC newbie is ridiculous. I am certainly no
newbie here (I have been surfing RAC for over 11 years, worked in the
industry at Phoenix Gold, and competed for years in IASCA). I have been
into car audio for over 22 years now. There is nothing wrong with car
audio mags.

MOSFET

[Captain_Howdy]

Enough said, you made fliers for PG. WOW an executive at AT&T at the age of
22-23 you should of been a CEO by the time you quit.


In article , "MOSFET"
wrote:
I worked in the marketing dept. (I have an MBA from the University of
Portland) from 2000-2001, Keith Peterson hired me.

At that time, I was also a college professor at the University of Portland.
I taught an evening class on Consumer Behavior to both graduates and
undergrads.

Before that, I had worked 10 years as an executive at AT&T.

I was forced to quit both jobs and move back to my home town of Stanwood,
Washington in late 2001 because my father had a heart attack and I was
needed to help run my family's company, Tanner Properties. We own office
buildings, apartment complexes, rental houses, etc.

That is what I still do today and to be totally honest, I don't miss the
"rat-race" AT ALL. I like being 'the boss" and living in my home town suits
my wife and I just fine.

Furthermore, with the sale of Phoenix Gold and Keith no longer at the helm,
I'm not sure I would have still wanted to work there.

Nicholas Tanner aka
MOSFET




"D.Kreft" wrote in message
roups.com...
MOSFET wrote:

I ... worked in the industry at Phoenix Gold

I didn't know that. What did you do there? How long did you work at PG?
And, if it's not too personal of a question, why did you leave?

-dan

[D.Kreft]

MOSFET wrote:

Wow. Quite an illustrious career. All I've done since kollege is play
basketball and write software. :-)

I was forced to quit both jobs and move back to my home town of Stanwood,

That makes you and I pretty much neighbors--I live in Kirkland. :-)

Furthermore, with the sale of Phoenix Gold and Keith no longer at the helm,
I'm not sure I would have still wanted to work there.

Yeah, Steve at JL told me that the industry as a whole has kinda taken
a slide...MB Quart, Precision Power, PG all changed hands and haven't
been the same since. :-(

-dan

[D.Kreft]

Eric Desrochers wrote:

Mostly, a subwoofer CANNOT be fast because it is band limited by
definition, by the crossover and/or its own natural response. Any
driver able to reproduce the frequency it is asked to reproduce will be
plenty fast. We want it to reproduce, say, up to 80 Hz? It can
reproduce 80 Hz at full volume? No need to be any faster than this.

I haven't read the article you've cited (I'm about 15 seconds away from
having my wife pull me off the computer to help her fold clothes, so
I'm in a rush :-), so I'm not sure what they're talking about when
they're discussing "fast" subwoofers. But my gut reaction is that I
would guess it depends upon one's definition of "fast".

There is always the concern of group delay--a quantitative measurement
of how quickly a driver or system can respond to the signal applied to
it. If you're talking about "fast" in this context, it makes perfect
sense.

There's also the acceleration the driver undergoes at the top and
bottom of its stroke when its velocity is zero. It's been eons since
I've taken a physics course or even had to discuss all this stuff, but
experience tells me that if I'm walking at 3 mph and I suddenly stop
and turn around and walk back at 3 mph, the amount of acceleration is
going to be less than if I'm running at 18 mph, stop and turn around
*in the same amount of time* (read "at the same frequency), and run
back the other way at 18 mph. So even if you're talking about "fast" in
this context I would think that it makes sense.

-dan

[D.Kreft]

Eric Desrochers wrote:

... And I wonder why because it's well known everywhere else that there
is no such thing.

My guess would be that in the circles you're talking about, you're
probably dealing more with people who have more theoretical
/mathematical background in acoustics and physics and they work in
environments were subtleties make more of a difference. In the car
audio realm, few people bother to learn the estoteric stuff because
much of it doesn't apply to a highly reflective, acoustically chaotic
environment where you typically have little to no control over where
you can put your speakers.

Then there's the typical age of the target audience you have to take
into consideration...some are too young to know or too immature to want
to know, while others of us have gotten so old we've *forgotten* more
than the young bucks know. :-)

A good place to start is :

http://www.soundstage.com/maxdb/maxdb061999.htm

I just read the whole article. Good stuff. I learned many moons ago
when I was a grasshopper installer that without good integration of
midbass and sub-bass, the latter will always sound like dogmeat. It's
why we would never design a system for anyone with a bandpass sub
enclosure unless they had at least 6.5" midbass drivers---and not just
flimsy Pioneer coaxes either--GOOD ones. Of course, sometimes we got
"bass monkey" kids who didn't care how good it sounded. You know the
type--the ones who think the only reason you put those "little
speakers" in the vehicle is so you can hear DMX cussing and spitting.

But even *with* solid midbass drivers, I still don't like bandpass
enclosures (either in the car *or* the home) because quite frankly they
have lousy response characteristics.

What is refered as a fast bass is actually a function of what is
happening in the mid-bass range. A fast, dynamic system will comprise
of good mid-bass in good enclosure and proper crossover settings. For
example, a 12 inches sub crossed over to cheap 5 inches mids will sound
slow and bloated.

My experience with such set-ups (or "mishaps" as they should probably
be called) is that the bass seems plenty "fast" but that voices come
from the back and it basically sounds really muddy. Maybe it's just a
matter of perception.

Another factor in the thightness of the sound may come from the tuning
of the box. It is generally understood that sealed boxes are more
damped, hence sound thighter and more true. But I think most already
know this!

I would tend to disagree on this point. I've found that customers who
described a system as "tight" usually did so referring to a response
curve that had a bit of a mid-bass bump and didn't have terrific
low-frequency extension. You've got to remember the vehicle's transfer
function...that automatic 12dB/octave bass boost can be a blessing and
a curse at the same time.

But then again, I used to sell and install in the 'hood where questions
like "Yeah, but do it 'quad'?" and commands such as "Krunk it up!!!!"
could be regularly heard. What they consider "tight" is likely to be
quite different than a golden-eared "tweak" who would use the same word
to describe a critically- or even over-damped system--the same system
that the boys in the hood might label as "whack".

This, in my estimation, highlights one of the big problems with
discussing audio performance--not everyone uses the same vocabulary and
they don't all have the same level of experience. Sometimes, you just
have to experiment a lot to figure out what they're talking about. For
example, we had one customer--a guy in his early 40's with a big Chevy
Dually P/U with an obscenely loud system in it (I hated the way it
sounded). He kept coming in telling us that his mids and highs were too
quiet and so we kept tweaking his gain and doing everything we could
think of--even putting in a bigger amp for his mids and highs, and
nothing worked. Then one day, one of the installers got to talking to
him and got an idea...he went out and turned *down* his subs and the
guy was ecstatic. We thought he said he wanted his mids and highs to
match his subs, but what made him happy was matching his subs to his
mids and highs.

It's a tricky business....figuring people out, and all. :-)

http://homepage.mac.com/dero72

Too bad I don't sprechen sie no French. :-)

-dan

[MOSFET]

Wow. Quite an illustrious career. All I've done since kollege is play
basketball and write software. :-)

I was forced to quit both jobs and move back to my home town of
Stanwood,

That makes you and I pretty much neighbors--I live in Kirkland. :-)

Did you go to the Udub?

That's where I got my undergraduate degree. I got hired by AT&T right out
of business school at the UofW. And then I got part of my Master's degree
at Seattle University (AT&T paid for my Masters so I decided to go to the
most expensive school I could, heh, heh) before AT&T transferred me to
Portland on a promotion. That's how I ended up in Portland and then
finished my Master's at Uof P. Both SU and Uof P are private Catholic
schools.

Kirkland, wow, we're practically neighbors.

Nick

[MOSFET]

"Captain_Howdy" wrote in message
...
The whole thing just screams your name, Misfit the junk collector.
What did you do at Phoenix Gold other then sweep the parking lot?
Where are all of your IASCA trophies, did your pet monkey eat them?
You've have been into car audio for over 22 years now and you still don't
know
****. That's why you give damaging advice just like your friend Bob.


Yes, sure whatever you say Howdy.

Take care,

MOSFET

[[email protected]]

D.Kreft wrote:

...For example, we had one customer--a guy in his early 40's with a big
Chevy Dually P/U with an obscenely loud system in it (I hated the way it
sounded). He kept coming in telling us that his mids and highs were too
quiet and so we kept tweaking his gain and doing everything we could
think of--even putting in a bigger amp for his mids and highs, and
nothing worked. Then one day, one of the installers got to talking to
him and got an idea...he went out and turned *down* his subs and the
guy was ecstatic. We thought he said he wanted his mids and highs to
match his subs, but what made him happy was matching his subs to his
mids and highs.

That's exactly why ThugBass systems sound so unbalanced. Many times all
you hear is the tinny edge of cymbals drowned in bass. Or, from the
outside with windows closed you hear nothing _but_ bass.

I have no problem using an EQ inside the distortion-prone interior of a
car. Tweaking a system with amps and crossovers can be expensive
guesswork. It also depends on the song you're playing. You can fine
tune it for one type of music but it gets boomy or buzzy with others.
An EQ is mandatory, I think - except in a home system with a lot more
forgiving air-space.

Brad

[D.Kreft]

MOSFET wrote:

Did you go to the Udub?

No, Northwestern University.

http://the.kreft.net/journals/

Kirkland, wow, we're practically neighbors.

Yeah, so uhh...just make sure you keep your lawn mowed and
everything'll be cool between us. :-)

-dan