I'm currently in the process of upgrading my car stereo system.

I just bought an Audiobahn A8002T amp based on numerous recommendations,
shown at link below.

http://www.onlinecarstereo.com/CarAu...spx?ProductID=
13487

Now, I already have a nice sealed box for a 10" subwoofer. Right now,
the sub I have in there is a RFosgate Punch P1 which will not be able to
handle the bridged power of the new amp.

Am I better off finding a 4 ohm SVC sub that can handle the amp's power
and bridging it or would it sound significantly better if I found a DVC
sub that I could hook up in parallel?

If at all possible I would like to stay at 1 10 inch sub (For space
reasons; it's a 95 BMW 325).

Finally, any suggestions on 1 10 inch sub (preferably under $200) that
would work well for this situation.

Thanks in advance for any help you can give me...



--
Jack Foley, Esq.

"Works on Contingency? No. Money Down!"
-Lionel Hutz (Phil Hartman, RIP)

"Have fun, stay cool, try to be
happy in this imperfect world and
don't forget to drink more than you can
handle. It helps the lawyers."
-George Carlin

I'm currently in the process of upgrading my car stereo system.

I just bought an Audiobahn A8002T amp based on numerous recommendations,
shown at link below.

http://www.onlinecarstereo.com/CarAu...spx?ProductID=
13487

Now, I already have a nice sealed box for a 10" subwoofer. Right now,
the sub I have in there is a RFosgate Punch P1 which will not be able to
handle the bridged power of the new amp.

Am I better off finding a 4 ohm SVC sub that can handle the amp's power
and bridging it or would it sound significantly better if I found a DVC
sub that I could hook up in parallel?

It makes no difference. In either case, you'd be delivering 800 watts to
the speaker - 800x1 or 400x2. Technically, by going the DVC route you'd be
reducing crossover distortion and asymmetric clipping, but such effects are
so minor that they're not even worth addressing. I bring them up only
because you may get someone (who knows just enough to be dangerous)
replying, "Obviously you should go the latter route to eliminate crossover
distortion and asymmetric clipping!"

Interestingly, Audiobahn provides 200x2 ratings at 4 ohm stereo and 800x1 at
4 ohms bridged for that amp, which implies that this amplifier has zero
output impedance. It's just defied the laws of physics. Neato! (sorry,
just a shot at manufacturers for lying about power ratings again)


If at all possible I would like to stay at 1 10 inch sub (For space
reasons; it's a 95 BMW 325).

Finally, any suggestions on 1 10 inch sub (preferably under $200) that
would work well for this situation.

Thanks in advance for any help you can give me...

There are a lot of manufacturers these days who are building 10" subwoofers
capable of handling 800 watts. Some of them, however, don't even make the
claim that they can handle that much. My JL 12w3 (not the recent
generation, which I understand is a different animal) is an example of that.
I think JL claims that it could handle 300 watts, whereas I've been powering
it with about 600 watts for a couple years now.

Jack Foley, Esq wrote
I'm currently in the process of upgrading my car stereo system.

I just bought an Audiobahn A8002T amp based on numerous recommendations,
shown at link below.

http://www.onlinecarstereo.com/CarAu...spx?ProductID=
13487

Now, I already have a nice sealed box for a 10" subwoofer. Right now,
the sub I have in there is a RFosgate Punch P1 which will not be able to
handle the bridged power of the new amp.

Is this observation strictly based on the rated power handling of the
speaker?
Would you be willing to audition the Punch on the new amp and see how it
sounds?

Am I better off finding a 4 ohm SVC sub that can handle the amp's power
and bridging it or would it sound significantly better if I found a DVC
sub that I could hook up in parallel?

Six to one, half dozen to the other (but Mark already explained all that)

MZ wrote:

I'm currently in the process of upgrading my car stereo system.

I just bought an Audiobahn A8002T amp based on numerous recommendations,
shown at link below.

http://www.onlinecarstereo.com/CarAu...spx?ProductID=
13487

Now, I already have a nice sealed box for a 10" subwoofer. Right now,
the sub I have in there is a RFosgate Punch P1 which will not be able to
handle the bridged power of the new amp.

Am I better off finding a 4 ohm SVC sub that can handle the amp's power
and bridging it or would it sound significantly better if I found a DVC
sub that I could hook up in parallel?


It makes no difference. In either case, you'd be delivering 800 watts to
the speaker - 800x1 or 400x2. Technically, by going the DVC route you'd be
reducing crossover distortion and asymmetric clipping, but such effects are
so minor that they're not even worth addressing. I bring them up only
because you may get someone (who knows just enough to be dangerous)
replying, "Obviously you should go the latter route to eliminate crossover
distortion and asymmetric clipping!"

Interestingly, Audiobahn provides 200x2 ratings at 4 ohm stereo and 800x1 at
4 ohms bridged for that amp, which implies that this amplifier has zero
output impedance. It's just defied the laws of physics. Neato! (sorry,
just a shot at manufacturers for lying about power ratings again)



If at all possible I would like to stay at 1 10 inch sub (For space
reasons; it's a 95 BMW 325).

Finally, any suggestions on 1 10 inch sub (preferably under $200) that
would work well for this situation.

Thanks in advance for any help you can give me...


There are a lot of manufacturers these days who are building 10" subwoofers
capable of handling 800 watts. Some of them, however, don't even make the
claim that they can handle that much. My JL 12w3 (not the recent
generation, which I understand is a different animal) is an example of that.
I think JL claims that it could handle 300 watts, whereas I've been powering
it with about 600 watts for a couple years now.




I don't have any problem with the post, I just think it's interesting
that lots of dialogue about amplifier/speak compatibility seems to make
the assumption that listeners use their equipment at full throttle. I'm
guessing 80% of the time, many don't use the "800w" amplifiers full
potential. Just my opinion....

I don't have any problem with the post, I just think it's interesting
that lots of dialogue about amplifier/speak compatibility seems to make
the assumption that listeners use their equipment at full throttle. I'm
guessing 80% of the time, many don't use the "800w" amplifiers full
potential. Just my opinion....

I think you'd be surprised just how much power transients contain. Typical
estimates for the "crest factor" of most common forms of music tend to be on
the order of 15 dB or so. In other words, the ratio between peak output and
mean output is somewhere around 30. That means even if the mean level of
your subwoofer output is 26 watts, you'd need an 800 watt amplifier to be
able to reproduce the transients without driving it into clipping.

Now, I'd suspect those numbers aren't entirely correct because we're talking
about subwoofer frequencies, which I suspect would have a much lower crest
factor than the broadband signal, but I think you get the point...

MZ wrote:

I don't have any problem with the post, I just think it's interesting
that lots of dialogue about amplifier/speak compatibility seems to make
the assumption that listeners use their equipment at full throttle. I'm
guessing 80% of the time, many don't use the "800w" amplifiers full
potential. Just my opinion....


I think you'd be surprised just how much power transients contain. Typical
estimates for the "crest factor" of most common forms of music tend to be on
the order of 15 dB or so. In other words, the ratio between peak output and
mean output is somewhere around 30. That means even if the mean level of
your subwoofer output is 26 watts, you'd need an 800 watt amplifier to be
able to reproduce the transients without driving it into clipping.

Now, I'd suspect those numbers aren't entirely correct because we're talking
about subwoofer frequencies, which I suspect would have a much lower crest
factor than the broadband signal, but I think you get the point...



Yes, quite true indeed. I've always been in a habit of buying more power
("potential" power as I like to view to it) than I think I'd use
frequently to ensure adequate headroom. I've been fortunate to not have
ever blown a driver due to power.

"MZ" wrote in message
...

I think you'd be surprised just how much power transients contain.
Typical
estimates for the "crest factor" of most common forms of music tend to be
on
the order of 15 dB or so. In other words, the ratio between peak output
and
mean output is somewhere around 30. That means even if the mean level of
your subwoofer output is 26 watts, you'd need an 800 watt amplifier to be
able to reproduce the transients without driving it into clipping.

Now, I'd suspect those numbers aren't entirely correct because we're
talking
about subwoofer frequencies, which I suspect would have a much lower crest
factor than the broadband signal, but I think you get the point...

Yeah, but still it depends on how dynamic your music is. I think some
people way underestimate how much power it takes to cover those dynamic
transients, but when the dynamic range of most of the pop/rock most people
listen to is about 3dB, I'm not sure how much it matters. Classical music
can be scarily dynamic, and rock music can be numbingly consistent. And
since you mentioned subwoofer frequencies, there can be frequency
compression too. Rock music can sound real "thumpy" when there's a peak
around 60 Hz, but it rolls off fast below that. Now play some music that
has some real low frequency, and again it can be scary. Not necessarily
because of "slam" or raw volume, but because you feel the music on a level
you're barely conscious of, like that sort of rumble you feel when a big
truck or train goes past you - let's say some nice organ or kettle drum or
massed double basses or something. That definitely needs power for
transients.

Yeah, but still it depends on how dynamic your music is. I think some
people way underestimate how much power it takes to cover those dynamic
transients, but when the dynamic range of most of the pop/rock most people
listen to is about 3dB, I'm not sure how much it matters.

Again, it's not really a matter of dynamic range, but rather crest factor,
which isn't exactly the same thing. And even for the highly compressed pop
music today, it's much greater than 3 dB.

Classical music
can be scarily dynamic, and rock music can be numbingly consistent. And
since you mentioned subwoofer frequencies, there can be frequency
compression too. Rock music can sound real "thumpy" when there's a peak
around 60 Hz, but it rolls off fast below that.

That's a good point. It's typical for most kinds of music, actually, to
experience a dip in overall power content below about 50-60 Hz. Above about
100 Hz, the 1/f rule is a good estimation.