I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

Well, what is 'your' opinion of the 'best' sub...

n8



I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

My experience is limited, which is why I'm asking for more knowlegeable
opinions. I've owned JL Audio subs and have been very happy with their
performance. A guy at a "high-end" shop tried to sell me on Image Dynamics.
Checked out their website and they look good on paper...then again most
anything looks good on paper.


"n8 skow" wrote in message
newsNjmc.44324$Fl5.7804@okepread04...
Well, what is 'your' opinion of the 'best' sub...

n8



I'm looking for opinions on the best subwoofer available at any price.
My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

"I've owned JL Audio subs and have been very happy with their performance."

Then you should be happy with a W7.

"A guy at a "high-end" shop tried to sell me on Image Dynamics."

And you certainly wouldn't be unhappy with one of those, either!!

Tony



--



What's more likely? That an all-powerful mysterious god created the
universe and then decided not to give any proof of his existence? Or, that
he simply doesn't exist at all? And that we created him so that we wouldn't
have to feel so small and alone. -Eleanor Arroway, Contact

"Tim Louquet" wrote in message
ink.net...
My experience is limited, which is why I'm asking for more knowlegeable
opinions. I've owned JL Audio subs and have been very happy with their
performance. A guy at a "high-end" shop tried to sell me on Image
Dynamics.
Checked out their website and they look good on paper...then again most
anything looks good on paper.


"n8 skow" wrote in message
newsNjmc.44324$Fl5.7804@okepread04...
Well, what is 'your' opinion of the 'best' sub...

n8



I'm looking for opinions on the best subwoofer available at any price.
My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety
of
music but mostly rock and hip-hop. Thanks for your suggestions.

Tony Fernandes wrote
"I've owned JL Audio subs and have been very happy with their
performance."

Then you should be happy with a W7.

A W7 on 300W? Are you insane?
Perhaps a W3v2 from JL would be appropriate (dual 2-ohm)

"A guy at a "high-end" shop tried to sell me on Image Dynamics."

And you certainly wouldn't be unhappy with one of those, either!!

ID gets more than it's share of nods on RAC, most people like the bonus of
small space requirements (especially with the IDQ line).

Here is a small list of recommendations (in no particular order and by no
means complete):
- Adire
- Kicker
- Rockford Fosgate
- Focal
- Orion
- Alpine
- Pioneer
- Cerwin Vega
- Elemental Designs
- Kaption
- Kenwood
- Oz Audio
- PPI

For the most part, the install makes all the difference.

"I've owned JL Audio subs and have been very happy with their
performance."

Then you should be happy with a W7.

Overkill. Maybe a 12w0 or 12w3 or something, if they're still making those.
I don't know what kind of crazy crap JL is up to these days.

Then you should be happy with a W7.

A W7 on 300W? Are you insane?

Yes, I am. Sorry, I was really tired. Missed that part.

Never mind!!

Tony



--



What's more likely? That an all-powerful mysterious god created the
universe and then decided not to give any proof of his existence? Or, that
he simply doesn't exist at all? And that we created him so that we wouldn't
have to feel so small and alone. -Eleanor Arroway, Contact

"Daniel Snooks" wrote in message
. ..
Tony Fernandes wrote
"I've owned JL Audio subs and have been very happy with their
performance."

Then you should be happy with a W7.

A W7 on 300W? Are you insane?
Perhaps a W3v2 from JL would be appropriate (dual 2-ohm)

"A guy at a "high-end" shop tried to sell me on Image Dynamics."

And you certainly wouldn't be unhappy with one of those, either!!

ID gets more than it's share of nods on RAC, most people like the bonus
of
small space requirements (especially with the IDQ line).

Here is a small list of recommendations (in no particular order and by no
means complete):
- Adire
- Kicker
- Rockford Fosgate
- Focal
- Orion
- Alpine
- Pioneer
- Cerwin Vega
- Elemental Designs
- Kaption
- Kenwood
- Oz Audio
- PPI

For the most part, the install makes all the difference.

Tim Louquet wrote:

I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

I use and like a NHT 1259, with the same power as you mentionned. Be
warned that it needs a big enclosure. Mine have 2.5 cu-feet, sealed.

They sell those at madisound.com for 150 USD

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

Hiroshima 45, Tchernobyl 86, Windows 95

"Daniel Snooks" wrote in message
. ..
Tony Fernandes wrote
"I've owned JL Audio subs and have been very happy with their
performance."

Then you should be happy with a W7.

A W7 on 300W? Are you insane?

/snip/

what the problem? are you saying it won't work on 300 watts?

Tim,

If it helps you any, I currently have a Directed Electronics amp that sends
300 Watts RMS to my Eclipse sub (87121 DVC). The enclosure is no more than
..75 cubic ft. I get good performance on just about any type of music
(including rock and hip hop).

P.S. - The JLAudio 12W7 needs about 1000W RMS to function best.
--
--------------------------------------------------------------
Vote for my install @ sounddomain.com!
http://www.sounddomain.com/id/blaqaltima
--------------------------------------------------------------

"Tim Louquet" wrote in message
ink.net...
I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

"Onyi C. Ejiasa" wrote in message
...
Tim,

If it helps you any, I currently have a Directed Electronics amp that
sends
300 Watts RMS to my Eclipse sub (87121 DVC). The enclosure is no more than
.75 cubic ft. I get good performance on just about any type of music
(including rock and hip hop).

P.S. - The JLAudio 12W7 needs about 1000W RMS to function best.
--

I would consider that sub to be a piece of junk then. 1000 watts on a sub is
competition material.
http://www.mtx.com/caraudio/headtohead/w7.cfm

Thanks everyone for your input. Now, let me pose this scenario. JL says
their 10W7 runs optimally at 500W RMS with an impedance of 3 ohms. My amp
is rated for 300W RMS at 4 ohms and 600W RMS at 2 ohms. The amp is said to
be stable down to 1 ohm. Would this then put me in the right ballpark with
my amp and the JL 10W7? I know a 12W7 is out of the question and, frankly,
12" of sub is probably too much for my setup anyway. Thanks again.




"Tim Louquet" wrote in message
ink.net...
I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

Thanks everyone for your input. Now, let me pose this scenario. JL says
their 10W7 runs optimally at 500W RMS with an impedance of 3 ohms.

What did they base this foolishness on? FYI - the JL tech support team is
notorious for not knowing what the hell they're talking about. Do we have
to go back to that sorry excuse for a tech site at jlaudio.com and tear it
apart again?

My amp
is rated for 300W RMS at 4 ohms and 600W RMS at 2 ohms.

Those are the ratings, sure, but they're obviously not accurate because what
you describe above is physically impossible for the kind of consumer grade
components every car audio amplifier manufacturer that I know of uses. So I
think your best bet would be to tell us which amp you're referring to
specifically.

The amp is said to
be stable down to 1 ohm. Would this then put me in the right ballpark
with
my amp and the JL 10W7? I know a 12W7 is out of the question and,
frankly,
12" of sub is probably too much for my setup anyway. Thanks again.

Why would you suspect that a 12" sub is out of the question for you?

Scott Johnson wrote

"Daniel Snooks" wrote in message
. ..
Tony Fernandes wrote
"I've owned JL Audio subs and have been very happy with their
performance."

Then you should be happy with a W7.

A W7 on 300W? Are you insane?

/snip/

what the problem? are you saying it won't work on 300 watts?

Never even hinted that it wouldn't work. However, if I am going to burn that
kind of cash on a sub you can be damn sure I won't settle for less then a
1/4 of the power it can handle. It would be a colossal waste of money.

I had a pair of JL Audio 12w7's running on a pair of rockford 1050s's, I was
impressed on the low side but musically i think it sounded a little muddy.
There are a lot of people out there that would have to agree with me. For
the money I would not purchase the W7. Right now I have 3 jlaudio 12w6v2's
and they hit alot better musically than the w7's but if you want them to hit
the lows better you have to make the box a little bigger than the
recommendation, not much though. The RMS or the sub is also right in your
ballpark.
"Tim Louquet" wrote in message
ink.net...
I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

Those are the ratings, sure, but they're obviously not accurate because
what
you describe above is physically impossible for the kind of consumer grade
components every car audio amplifier manufacturer that I know of uses. So
I
think your best bet would be to tell us which amp you're referring to
specifically.

I'm going to use a McIntosh MCC301M mono amp to power the sub. I'm
currently running an MCC444 4-channel to power my three-way components and
have been thrilled with the performance. I have no reason to believe that
McIntosh would over-state their power ratings...or would they?

A 12" sub would be great to be sure. I figured a 10" would suit my needs a
little better due to the ever-present space considerations which, in my
case, are pretty tight. The box and amp have to fit somewhere in the cab of
my Freightliner work-truck. It's a day-cab, which means there is no sleeper
bunk, so basically what I have to work with is roughly the space a
two-seater pickup truck would have.

Those are the ratings, sure, but they're obviously not accurate because
what
you describe above is physically impossible for the kind of consumer
grade
components every car audio amplifier manufacturer that I know of uses.
So
I
think your best bet would be to tell us which amp you're referring to
specifically.

I'm going to use a McIntosh MCC301M mono amp to power the sub. I'm
currently running an MCC444 4-channel to power my three-way components and
have been thrilled with the performance. I have no reason to believe that
McIntosh would over-state their power ratings...or would they?

It's hard to say. I haven't dealt with enough McIntosh amps to say for
certain. The last one I dealt with was about 5 years ago. Anyway, if
they're correct about their 300 watt rating, then expect approximately 500
watts when halving the impedance. Again, I don't know whether or not the
300 watt rating is accurate, underrated, or overrated.

A 12" sub would be great to be sure. I figured a 10" would suit my needs
a
little better due to the ever-present space considerations which, in my
case, are pretty tight. The box and amp have to fit somewhere in the cab
of
my Freightliner work-truck. It's a day-cab, which means there is no
sleeper
bunk, so basically what I have to work with is roughly the space a
two-seater pickup truck would have.

Ah yes, a 10 with a smallish magnet (by today's standards, at least) may be
best. You're right.

alright well, no offense to the maggots on this group who all think they
know everything about everything, but id go with two 10 inch SVC premier
subs(around .5 or .6 cu ft per sub for enclosure)... great SQ, and a decent
thump..that will give yo a 2 ohm impedance wired in parallel, sicne they are
4 ohms each. that will soudn VERY respectable


I'm going to use a McIntosh MCC301M mono amp to power the sub. I'm
currently running an MCC444 4-channel to power my three-way components and
have been thrilled with the performance. I have no reason to believe that
McIntosh would over-state their power ratings...or would they?

A 12" sub would be great to be sure. I figured a 10" would suit my needs
a
little better due to the ever-present space considerations which, in my
case, are pretty tight. The box and amp have to fit somewhere in the cab
of
my Freightliner work-truck. It's a day-cab, which means there is no
sleeper
bunk, so basically what I have to work with is roughly the space a
two-seater pickup truck would have.

Nothing funnier than starting your reply with an insult.... and then
redefining what it is...

=)
n8



alright well, no offense to the maggots on this group who all think they
know everything about everything, but id go with two 10 inch SVC premier
subs(around .5 or .6 cu ft per sub for enclosure)... great SQ, and a
decent
thump..that will give yo a 2 ohm impedance wired in parallel, sicne they
are
4 ohms each. that will soudn VERY respectable


I'm going to use a McIntosh MCC301M mono amp to power the sub. I'm
currently running an MCC444 4-channel to power my three-way components
and
have been thrilled with the performance. I have no reason to believe
that
McIntosh would over-state their power ratings...or would they?

A 12" sub would be great to be sure. I figured a 10" would suit my
needs
a
little better due to the ever-present space considerations which, in my
case, are pretty tight. The box and amp have to fit somewhere in the
cab
of
my Freightliner work-truck. It's a day-cab, which means there is no
sleeper
bunk, so basically what I have to work with is roughly the space a
two-seater pickup truck would have.

this is true.. i did do that, didn't I? hahah


"n8 skow" wrote in message
news:6vZnc.50261$Fl5.13460@okepread04...
Nothing funnier than starting your reply with an insult.... and then
redefining what it is...

=)
n8



alright well, no offense to the maggots on this group who all think they
know everything about everything, but id go with two 10 inch SVC premier
subs(around .5 or .6 cu ft per sub for enclosure)... great SQ, and a
decent
thump..that will give yo a 2 ohm impedance wired in parallel, sicne they
are
4 ohms each. that will soudn VERY respectable


I'm going to use a McIntosh MCC301M mono amp to power the sub. I'm
currently running an MCC444 4-channel to power my three-way components
and
have been thrilled with the performance. I have no reason to believe
that
McIntosh would over-state their power ratings...or would they?

A 12" sub would be great to be sure. I figured a 10" would suit my
needs
a
little better due to the ever-present space considerations which, in
my
case, are pretty tight. The box and amp have to fit somewhere in the
cab
of
my Freightliner work-truck. It's a day-cab, which means there is no
sleeper
bunk, so basically what I have to work with is roughly the space a
two-seater pickup truck would have.

There is no such thing! Reason: many subwoofers are made by one of two
companies. All the subs with very wide surrounds pay license royalties to
the holder of the patent: Earthquake Sound in Ca. Since amplifiers do not
push their wattage, it is drawn by the driver as it needs wattage. Small
drivers like tweeters and midrange draw very little wattage, but subwoofers
draw more. The lower the frequency, the more wattage is needed. 300wrms is
enought to drive any good 12" subwoofer. The enclosure will determine how
good the bass sounds.A sealed box facing the car behind you will never
produce the most accurate, deep, tight, bass for all the money spent. If the
box (bandpass design) was ported partially external from the top of the box,
so it could pass throught the rear deck, it would deliver the bass into the
INTERIOR of the car ( a novel idea!). Any woofer of good quality will
produce low frequencies regardless of the type of music played. Visit
www.earthquakesound.com .P.


"Tim Louquet" wrote in message
ink.net...
I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

Peter Klein's list of errors:

1. Reason: many subwoofers are made by one of two
companies.
2. All the subs with very wide surrounds pay license royalties to
the holder of the patent: Earthquake Sound in Ca.
3. Since amplifiers do not
push their wattage, it is drawn by the driver as it needs wattage.
4. A sealed box facing the car behind you will never
produce the most accurate, deep, tight, bass for all the money spent.
5. If the
box (bandpass design) was ported partially external from the top of the
box,
so it could pass throught the rear deck, it would deliver the bass into
the
INTERIOR of the car ( a novel idea!).
6. Any woofer of good quality will
produce low frequencies regardless of the type of music played.

"Peter Klein" wrote in message
news:eeUqc.36361$6f5.3698998@attbi_s54...

/SNIP/

Peter,
It is evident that you know very little about car audio. Stop now with
your lies and errors.

There is no such thing! Reason: many subwoofers are made by one of two
companies.

Who are the two companies that are making so many of the subs on the
market, and which of the big names in car audio are using subs built
by these two manufacturers?

While there *are* subwoofers that are built by one company and sold
under another company's brand name, this isn't the case for any of the
brands that are likely to come up in a serious discussion of "best
subs". Just to name three examples, I believe JL Audio, Image
Dynamics, and Adire all manufacture their own subs rather than simply
re-badging someone else's. I suspect the same is true for Infinity,
MB Quart, Alpine, and most of the other big brands. While the 15"
"Boom-A-Lot" brand subs you find at flea markets for $50 are probably
a mass-produced item with the "Boom-A-Lot" logo silkscreened onto
them, I don't think this practice is very common among high-end subs.
There's simply too much competition between the high-end players, and
too much money spent on research and development, for the high-end
manufacturers to sell their subs out the back door for any yahoo to
slap his logo onto it and re-sell it.

Also, I find it hard to believe any serious manufacturer in the
subwoofer market is paying royalties to Earthquake for a
very-wide-surround design, for two reasons:

1) Compared to the history of loudspeakers, Earthquake hasn't been
around all that long, so I doubt they hold any patent on something as
simple as using a wide surround, considering the sheer amount of prior
work done in the field before they came around. Perhaps you could
post the patent number so we can look it up and see exactly what
Earthquake holds the patent for?

2) Having a very wide surround in a subwoofer is a poor design
decision anyway, since it reduces the available amount of cone surface
area for a given basket diameter. This is why JL (among other
companies) has gone to using a taller, narrower surround. If you look
at the cross-section of the surround used on their W7 subs, it's so
tall and narrow that it's almost a semi-circle or an arch. Since the
surround is narrower, the cone area can be larger, giving the 13W7 the
same piston displacement area as a conventional 15-inch sub that uses
a wider surround.

Scott Gardner


On Thu, 20 May 2004 01:55:26 GMT, "Peter Klein"
wrote:

All the subs with very wide surrounds pay license royalties to
the holder of the patent: Earthquake Sound in Ca. Since amplifiers do not
push their wattage, it is drawn by the driver as it needs wattage. Small
drivers like tweeters and midrange draw very little wattage, but subwoofers
draw more. The lower the frequency, the more wattage is needed. 300wrms is
enought to drive any good 12" subwoofer. The enclosure will determine how
good the bass sounds.A sealed box facing the car behind you will never
produce the most accurate, deep, tight, bass for all the money spent. If the
box (bandpass design) was ported partially external from the top of the box,
so it could pass throught the rear deck, it would deliver the bass into the
INTERIOR of the car ( a novel idea!). Any woofer of good quality will
produce low frequencies regardless of the type of music played. Visit
www.earthquakesound.com .P.


"Tim Louquet" wrote in message
link.net...
I'm looking for opinions on the best subwoofer available at any price. My
amp pushes 300W rms at 4 ohms. I'd like either a 10" or a 12" single
subwoofer in a sealed enclosure. I'll be listening to a wide variety of
music but mostly rock and hip-hop. Thanks for your suggestions.

It's true that amplifiers don't "push" their power, they only provide
their power based on what the speakers draw. That being said, the
draw from the speaker is ONLY dependent on the speaker impedance, NOT
the physical size of the speaker itself. If a speaker has an
impedance of 4 ohms at a particular frequency, and an amp provides
300W into that impedance, it doesn't matter whether the speaker is a
subwoofer or a tweeter - as long as the impedence is the same, the
power delivered by the amp will be the same.

The main reasons why people don't provide as much power to their
mids and tweeters as they do to their subs a

1) Subwoofers are generally less efficient, because the moving parts
(coil, cone, and surround) are more massive, and require more force to
accelerate/decelerate.

2) (And this is the big reason) Our ears are *much* less sensitive to
low frequencies than they are to higher frequencies. 140 dB at 50 hz
will tickle your belly and give you the "thump in the chest" that many
people love, but 140 dB at 8 khz will leave you writhing in pain on
the floor. This is why even the best systems don't have a
perfectly-flat frequency response. The response intentionally slopes
upward as the frequency gets lower, to compensate for our reduced
sensitivity to low-frequency sounds.

Scott Gardner





On Thu, 20 May 2004 01:55:26 GMT, "Peter Klein"
wrote:

Since amplifiers do not
push their wattage, it is drawn by the driver as it needs wattage. Small
drivers like tweeters and midrange draw very little wattage, but subwoofers
draw more.

While ported boxes will generally play louder -at certain frequencies-
than a sealed box, there are several significant drawbacks to using
ported boxes:

The frequency response of a ported box is a lot more uneven compared
to the frequency response of the same sub in a sealed box. If you
look at the frequency response curve of a sealed box as the frequency
decreases, you'll see that the response rolls off gradually, at about
6 dB per octave. This means that even in the very low frequencies,
the sealed box will still be producing significant volume levels.

Now, look at the curve for a ported box as the frequency decreases.
As you approach the tuning frequency of the box, the response curve
will actually increase, giving you a nice 3-5 dB "hump" in a narrow
range of frequencies. As you go below that frequency, however, the
frequency response falls off like a rock, usually at 12 dB per octave
or more. This means that while a certain speaker may play 3-5 dB
louder near its tuning frequency compared to the same speaker in a
sealed box, the ported enclosure will be significantly quieter at
lower frequencies. Some people like ported boxes because of the
"hump" near the tuning frequency, but I prefer to use sealed boxes
because the response is more even. If I want more SPL, I just buy a
bigger amplifier - watts are cheap these days.

Also, sealed boxes are much more forgiving of errors in box volume.
You can go plus or minus 10% on the enclosure size before you really
start to notice a difference. Since a ported box is essentially a big
"whistle", tuned to resonate at a certain frequency, the volume
measurements are a lot more critical to the speaker's performance.

Since the air volume in a sealed box (also called 'acoustic
suspension', for the following reason) is sealed, it acts as a
"cushion" to help keep the sub from overextending, so sealed
enclosures tend to be more forgiving if you occasionally overpower the
speaker. In a ported enclosure playing at or near its tuning
frequency, there's almost no cushioning effect, so it will be a lot
easier to "bottom out" or possibly damage your subwoofer if you
overpower it. This is why you often hear a mechanical "clacking"
noise from a ported box when it's driven very hard near its resonant
frequency - that's the sound of the mechanicals of the subwoofer
hitting the end of their excursion travel.

In a ported box, you also have the potential for audible port noise,
or "huffing", especially if the port is connected directly into the
passenger compartment. Since a sealed box has no ports, there's
obviously no potential for port noise.

As for "accuracy" and "tightness", those are subjective terms, but
given the smoother, flatter response curve for a sealed box, I'd argue
that a sealed box is actually more accurate, and there's a lot of
evidence that sealed boxes sound "tighter" as well. With a
well-designed ported box, the differences can be minimized, but you're
still more at risk of ending up with thudding, "one-note" bass using a
marginally-designed ported box than with a sealed box.

I won't go into front-facing versus rear-facing subs, since that's
been beaten to death in this group.

Scott Gardner





On Thu, 20 May 2004 01:55:26 GMT, "Peter Klein"
wrote:

A sealed box facing the car behind you will never
produce the most accurate, deep, tight, bass for all the money spent. If the
box (bandpass design) was ported partially external from the top of the box,
so it could pass throught the rear deck, it would deliver the bass into the
INTERIOR of the car ( a novel idea!).

Quick correction to my post - the typical rolloffs for sealed and
ported boxes are 12 dB/octave and 24 dB/octave respectively, not
6dB/octave and 12 dB/octave as I posted earlier.

While you can use a bandpass design rather than a simple ported design
to get a 12 dB/octave rolloff from a vented box, keep in mind that the
12 dB/octave rolloff in a bandpass box occurs both below AND above the
tuning frequency, which means that it will play great near its tuning
frequency, but now the response curve falls away on BOTH sides of the
tuning frequency, not just on the low side. This is still less
accurate than a sealed box, and unless you've been extremely accurate
with both your volume/port calculations and your box construction,
you're back to that whole "one-note bass" problem.

Scott Gardner



On Thu, 20 May 2004 05:44:23 -0400, Scott Gardner
wrote:

The frequency response of a ported box is a lot more uneven compared
to the frequency response of the same sub in a sealed box. If you
look at the frequency response curve of a sealed box as the frequency
decreases, you'll see that the response rolls off gradually, at about
6 dB per octave. This means that even in the very low frequencies,
the sealed box will still be producing significant volume levels.

Now, look at the curve for a ported box as the frequency decreases.
As you approach the tuning frequency of the box, the response curve
will actually increase, giving you a nice 3-5 dB "hump" in a narrow
range of frequencies. As you go below that frequency, however, the
frequency response falls off like a rock, usually at 12 dB per octave
or more.

Hey Scott. You've just written an entire section to be added to the FAQ.


--
Mark
remove "remove" and "spam" to reply


"Scott Gardner" wrote in message
...
Quick correction to my post - the typical rolloffs for sealed and
ported boxes are 12 dB/octave and 24 dB/octave respectively, not
6dB/octave and 12 dB/octave as I posted earlier.

While you can use a bandpass design rather than a simple ported design
to get a 12 dB/octave rolloff from a vented box, keep in mind that the
12 dB/octave rolloff in a bandpass box occurs both below AND above the
tuning frequency, which means that it will play great near its tuning
frequency, but now the response curve falls away on BOTH sides of the
tuning frequency, not just on the low side. This is still less
accurate than a sealed box, and unless you've been extremely accurate
with both your volume/port calculations and your box construction,
you're back to that whole "one-note bass" problem.

Scott Gardner



On Thu, 20 May 2004 05:44:23 -0400, Scott Gardner
wrote:

The frequency response of a ported box is a lot more uneven compared
to the frequency response of the same sub in a sealed box. If you
look at the frequency response curve of a sealed box as the frequency
decreases, you'll see that the response rolls off gradually, at about
6 dB per octave. This means that even in the very low frequencies,
the sealed box will still be producing significant volume levels.

Now, look at the curve for a ported box as the frequency decreases.
As you approach the tuning frequency of the box, the response curve
will actually increase, giving you a nice 3-5 dB "hump" in a narrow
range of frequencies. As you go below that frequency, however, the
frequency response falls off like a rock, usually at 12 dB per octave
or more.

Thanks - I felt bad posting three replies in a row (plus a correction
to one of my own mistakes), but there was just too much to address in
a single posting.

I think one of the goals of this forum should be education - God knows
I've learned a bunch here. I used to be a damping
factor/signal-to-noise-ratio zealot, until I learned enough of the
math and physics behind those factors to realize how low they can
actually be before you can hear a difference. With modern equipment,
the damping factors and S/N ratios are really just varying degrees of
overkill. Sure, a SNR of 102 dB is nice, but it's no reason to turn
up your nose at another piece that "only" has a SNR of 90 dB.

If you were serious about adding any part of my posts to the FAQ -
feel free, and there's no need to credit me (I don't know if entries
to the FAQ are even credited anyway.) Also, go ahead and edit it as
you see fit - I know I can be long-winded.

Scott Gardner



On Thu, 20 May 2004 11:11:23 -0400, "MZ"
wrote:

Hey Scott. You've just written an entire section to be added to the FAQ.

Scott Gardner wrote:

Thanks for the good post. I have a couple small additions. Also note that the
6/12 dB roll-offs of sealed/ported enclosure has been corrected to 12/24 dB in
a later post.

While ported boxes will generally play louder -at certain frequencies-
than a sealed box, there are several significant drawbacks to using
ported boxes:

The frequency response of a ported box is a lot more uneven compared
to the frequency response of the same sub in a sealed box. If you
look at the frequency response curve of a sealed box as the frequency
decreases, you'll see that the response rolls off gradually, at about
6 dB per octave. This means that even in the very low frequencies,
the sealed box will still be producing significant volume levels.

Actually the output of a ported box does not been to be less even. It is true
that most people and most manufacturer recommendations do use them that way but
its a choice. The other downside to ported enclosures is for a given level of
even bass performance a ported enclosure usually will be larger. Size is
another reason that people often opt for the ported humped bass response.


Also, sealed boxes are much more forgiving of errors in box volume.
You can go plus or minus 10% on the enclosure size before you really
start to notice a difference. Since a ported box is essentially a big
"whistle", tuned to resonate at a certain frequency, the volume
measurements are a lot more critical to the speaker's performance.

I like the whistle analogy. It works except that the woofer "blows" the whistle
when it's in rarefaction. But it is true that ported enclosures are harder to
design and tune. There's more to it than just enclosure volume as well;


Since the air volume in a sealed box (also called 'acoustic
suspension', for the following reason) is sealed, it acts as a
"cushion" to help keep the sub from overextending, so sealed
enclosures tend to be more forgiving if you occasionally overpower the
speaker. In a ported enclosure playing at or near its tuning
frequency, there's almost no cushioning effect, so it will be a lot
easier to "bottom out" or possibly damage your subwoofer if you
overpower it.

Actually one advantage of ported enclosures is the reduced excursion at the
system tuning frequency. The danger lies below the tuned frequency of the
system and with the availability of program material with plenty of content at
very low frequencies a ported enclosure should be electronically high-passed in
most cases.

This is why you often hear a mechanical "clacking"
noise from a ported box when it's driven very hard near its resonant
frequency - that's the sound of the mechanicals of the subwoofer
hitting the end of their excursion travel.

Or tinsel leads hitting the cone, etc. This tends to happen below system
resonance because driver excursion is minimized at system resonance but it
still a problem nonetheless. But I'd also like to point out that ported
enclosures often allow access to noises occuring inside the box that a sealed
enclosure will mask. So, in some small way it might be seen as an advantage.

In a ported box, you also have the potential for audible port noise,
or "huffing", especially if the port is connected directly into the
passenger compartment. Since a sealed box has no ports, there's
obviously no potential for port noise.

Wouldn't it be mice to have a microphone in there so you could get a report on
suspension/motor/mechanical noise :-)


As for "accuracy" and "tightness", those are subjective terms, but
given the smoother, flatter response curve for a sealed box, I'd argue
that a sealed box is actually more accurate, and there's a lot of
evidence that sealed boxes sound "tighter" as well. With a
well-designed ported box, the differences can be minimized, but you're
still more at risk of ending up with thudding, "one-note" bass using a
marginally-designed ported box than with a sealed box.

Cabin reinforcement is the one real freebie in car audio. With a sealed
enclosure you get a great match for normal system function. Your system is
rolling off at 12 dB per octave and below the lowest axial mode in your car
your cabin is offsetting it perfectly with a 12 dB per octave reinforcement (as
frequency falls.)

With a ported enclosure you are essentially forfeiting cabin gain below system
resonance because
the system will rolloff at 24 dB per octave.

Some of it may already be in the FAQ. I don't know. Anyway, I'm not the
one who decides what goes into the FAQ. You can contact Ian though if you
have a suggestion. See what's in there, and adapt what you wrote to fit.

www.mobileaudio.com/rac-faq

--
Mark
remove "remove" and "spam" to reply


"Scott Gardner" wrote in message
...
Thanks - I felt bad posting three replies in a row (plus a correction
to one of my own mistakes), but there was just too much to address in
a single posting.

I think one of the goals of this forum should be education - God knows
I've learned a bunch here. I used to be a damping
factor/signal-to-noise-ratio zealot, until I learned enough of the
math and physics behind those factors to realize how low they can
actually be before you can hear a difference. With modern equipment,
the damping factors and S/N ratios are really just varying degrees of
overkill. Sure, a SNR of 102 dB is nice, but it's no reason to turn
up your nose at another piece that "only" has a SNR of 90 dB.

If you were serious about adding any part of my posts to the FAQ -
feel free, and there's no need to credit me (I don't know if entries
to the FAQ are even credited anyway.) Also, go ahead and edit it as
you see fit - I know I can be long-winded.

Scott Gardner



On Thu, 20 May 2004 11:11:23 -0400, "MZ"
wrote:

Hey Scott. You've just written an entire section to be added to the FAQ.

"Scott Johnson" wrote in
message ...

"Onyi C. Ejiasa" wrote in message
...
Tim,

If it helps you any, I currently have a Directed Electronics amp that
sends
300 Watts RMS to my Eclipse sub (87121 DVC). The enclosure is no more
than
.75 cubic ft. I get good performance on just about any type of music
(including rock and hip hop).

P.S. - The JLAudio 12W7 needs about 1000W RMS to function best.
--

I would consider that sub to be a piece of junk then. 1000 watts on a sub
is
competition material.
http://www.mtx.com/caraudio/headtohead/w7.cfm

it's not a piece of junk, that's they way Mr. Smith and the crew designed
it, to work with 1kwrms or more.

"Scott Gardner" wrote in message
...
There is no such thing! Reason: many subwoofers are made by one of two
companies.

Who are the two companies that are making so many of the subs on the
market, and which of the big names in car audio are using subs built
by these two manufacturers?

While there *are* subwoofers that are built by one company and sold
under another company's brand name, this isn't the case for any of the
brands that are likely to come up in a serious discussion of "best
subs". Just to name three examples, I believe JL Audio, Image
Dynamics, and Adire all manufacture their own subs rather than simply
re-badging someone else's. I suspect the same is true for Infinity,
MB Quart, Alpine, and most of the other big brands. While the 15"
"Boom-A-Lot" brand subs you find at flea markets for $50 are probably
a mass-produced item with the "Boom-A-Lot" logo silkscreened onto
them, I don't think this practice is very common among high-end subs.
There's simply too much competition between the high-end players, and
too much money spent on research and development, for the high-end
manufacturers to sell their subs out the back door for any yahoo to
slap his logo onto it and re-sell it.

Also, I find it hard to believe any serious manufacturer in the
subwoofer market is paying royalties to Earthquake for a
very-wide-surround design, for two reasons:

1) Compared to the history of loudspeakers, Earthquake hasn't been
around all that long, so I doubt they hold any patent on something as
simple as using a wide surround, considering the sheer amount of prior
work done in the field before they came around. Perhaps you could
post the patent number so we can look it up and see exactly what
Earthquake holds the patent for?

2) Having a very wide surround in a subwoofer is a poor design
decision anyway, since it reduces the available amount of cone surface
area for a given basket diameter. This is why JL (among other
companies) has gone to using a taller, narrower surround. If you look
at the cross-section of the surround used on their W7 subs, it's so
tall and narrow that it's almost a semi-circle or an arch. Since the
surround is narrower, the cone area can be larger, giving the 13W7 the
same piston displacement area as a conventional 15-inch sub that uses
a wider surround.

Scott Gardner

Scott, JL gets all of it's cones and baskets from Pioneer past the w7

"Scott Gardner" wrote in message
...
Thanks - I felt bad posting three replies in a row (plus a correction
to one of my own mistakes), but there was just too much to address in
a single posting.

I think one of the goals of this forum should be education - God knows
I've learned a bunch here. I used to be a damping
factor/signal-to-noise-ratio zealot, until I learned enough of the
math and physics behind those factors to realize how low they can
actually be before you can hear a difference. With modern equipment,
the damping factors and S/N ratios are really just varying degrees of
overkill. Sure, a SNR of 102 dB is nice, but it's no reason to turn
up your nose at another piece that "only" has a SNR of 90 dB.

If you were serious about adding any part of my posts to the FAQ -
feel free, and there's no need to credit me (I don't know if entries
to the FAQ are even credited anyway.) Also, go ahead and edit it as
you see fit - I know I can be long-winded.

Scott Gardner

I thought I was the only one on the DF/S2N tip

Scott, JL gets all of it's cones and baskets from Pioneer past the w7


First of all, there is nothing "past" the W7. The W7 is their best sub. 2nd,
this is simply untrue, and I challenge you here as I did on the Audi board:
Porve this claim by providing a URL.

Amps do not send their total rated output to any subwoofer. The subwoofer is
an acoustic motor that runs on a fuel called wattage. The sub draws the
wattage as it needs it to produce the bass. 300 watts is definitely enough
to drive any 12" sub. What matters is the type of enclosure, is it a sealed
box or a more complex enclosure like a bandpass? P.

"Tha Ghee" wrote in message
...
"Scott Johnson" wrote in
message ...

"Onyi C. Ejiasa" wrote in message
...
Tim,

If it helps you any, I currently have a Directed Electronics amp that
sends
300 Watts RMS to my Eclipse sub (87121 DVC). The enclosure is no more
than
.75 cubic ft. I get good performance on just about any type of music
(including rock and hip hop).

P.S. - The JLAudio 12W7 needs about 1000W RMS to function best.
--

I would consider that sub to be a piece of junk then. 1000 watts on a
sub
is
competition material.
http://www.mtx.com/caraudio/headtohead/w7.cfm

it's not a piece of junk, that's they way Mr. Smith and the crew designed
it, to work with 1kwrms or more.

"Richard Kuschel" wrote in message
...

More stupidity ... if a sub is designed to handle 1000W RMS, it's not
going
to go very far with only 300W pushing it. Where are you getting this
information?

Where are you getting your information?

A speaker that can handle 1000 watts is only going to be aabout 5dB
quieter at
300 watts And that is going to be pretty loud even with the least
effecient of
speakers

Drive that amplifier into distortion and the speaker will over heat and
eventually burn out even if the speaker is rated for 1000 watts.

If and ONLY IF you exceed the power handling of the driver. If the power
ratings are actual then a 300W amp is not going to burn out a 1000 watt
driver. Even at severe clipping you could maybe get 600 watts out of it. Not
enough to burn out a true 1000 watt driver.




Richard H. Kuschel
"I canna change the law of physics."-----Scotty

I agree, unfortunately most audio myths have some background in physics that
has just been slightly twisted to make sense, at least until you examine
them closely.

Les

Peter Klein wrote
Amps do not send their total rated output to any subwoofer. The subwoofer
is
an acoustic motor that runs on a fuel called wattage. The sub draws the
wattage as it needs it to produce the bass.

Who told you this clap-trap?
If what you are saying is true, no-one would ever be able to blow their
speakers.

Now, in reality ... an amplifier receives signal from the pre-amp (head
unit) and amplifies that signal. That's it, no magic involved. The amplifier
could care less what speaker(s) may be wired to it.
Here is a simplistic scenario:
A given amp has the gain set to saturate with a 2V input signal (maximum
output given a 2V input) This amp is rated to produce 350W RMS x 1 @ 4ohm. A
4ohm sub is wired to it. It doesn't matter what the rated power handling of
the sub is, when a signal comes down the line at 2V strength, the amp will
be pushing 350W into the sub. If the sub can only handle 200W RMS then it
will bottom out because of the excessive power going through the coil. If
the sub can handle 1200W RMS then it will barely move with only 350W
applied.

300 watts is definitely enough
to drive any 12" sub.

More stupidity ... if a sub is designed to handle 1000W RMS, it's not going
to go very far with only 300W pushing it. Where are you getting this
information?

What matters is the type of enclosure, is it a sealed
box or a more complex enclosure like a bandpass? P.

Why does the enclosure type matter?

Daniel,

You wrote:

"If the sub can handle 1200W RMS then it will barely move with only 350W applied."

That is not necessarily true. It depends how efficient the speaker is. And 350 watts
ought to make even a 1200 watt rated sub more than "barely move."
--
Todd

You haven't played with the Diamond TDX have you? 1100 barely makes that
thing move.

Brandonb


Todd wrote:

Daniel,

You wrote:

"If the sub can handle 1200W RMS then it will barely move with only 350W applied."

That is not necessarily true. It depends how efficient the speaker is. And 350 watts
ought to make even a 1200 watt rated sub more than "barely move."