Mark and Scott,

My setup is as follows:
Car: 1999 Nissan Altima
Subs: Two 12" Infinity Reference 300W 4 ohm single voice coil subs. They
are in sealed 1.25 cubic foot boxes which is their recommended volume. I
have tried a ported box before and it didn't seem to help much. The subs
are in the traditional spot, firing backwards right behind my rear seats
in my trunk. The subs are wired directly to each of the two outputs of
the amp. It's my understanding that the amp is internally bridged, so
hooking a pair of 4 ohm SVC subs to the two terminals would result in a 2
ohm load.
Amp: The amp is rated at 1200W @ 1 ohm and 600W @ 2 ohms. I have the low
pass filter set at around 90 Hz (with no crossover functions on my head
unit). I have the subsonic filter turned off and the bass boost on the amp
turned to zero. I have set the gain with a digital multimeter so that
when I have my volume turned to 37 out of 62 (which is about the highest I
would turn it), a 50 Hz sine wave produces 34.6V or 600W @ 2 ohms.

The amp does have a remote gain level knob that I initially set to maximum
when setting the gain on my amp. However the last time I set it halfway
when setting the gain on my amp because I always had it at maximum before
and it seemed to be doing me no good as I would never turn it down.

I have a friend with a lesser setup than mine (smaller subs, less
powerful amp, similar sedan, sealed box) and his bass is very strong
even with very little bass boost. If there are any suggestions you guys
can make, I would be willing to try them out. Do you think maybe I set my
gain wrong somehow?

Thanks very much.
George

On Sun, 13 Mar 2005 00:20:22 -0500, Scott Gardner wrote:

Could be several things. First, I've always been happiest with a
slight amount of boost in the bass frequencies rather than setting
everything perfectly flat. Nothing near +12dB, though.

What frequencies are you sending to your subs? You mentioned that
you're boosting the 40 Hz region, but you didn't mention what your
low-pass crossover is. If your crossover is set very low, like 50 Hz,
and you're playing a lot of tapes, FM radio, MP3, or other sources
that don't have very much low-frequency information in them, you just
may not be sending much of anything to the subs in the first place.

Also, are you sure you have the amplifier gains set correctly on your
sub amp? How did you set them? What size/impedance are your subs?
Are you using the low-pass crossover on the head unit, on the
amplifier, or both? Could your subs be wired out-of-phase and
cancelling each other out? What kind of enclosure are your subs in?

It sounds like something's misconfigured, because depending on the
impedance of your subs, your amplifier should be capable of providing
somewhere between 450 and 1200 watts. Even just 450 watts into a pair
of subs should be more than enough to make your hair bounce.