Expert: Cleggsan - 9/7/2010

Question
Hi, sorry to bother you, hope this question is in your field of expertise. I  had just read one of your Q & A'S, and was wondering if I got it straight. Ok, I have two vehicles, two systems, they both sound fairly well, but not exactly what I'm looking for. ( 02' trailblazer- lanzar 256, mtx thunder 8000 dvc 4ohm 10"+ thunder 8000  svc 8 ohm 12", dvc wired in series internally, and subs bridged in parallel) and ( 02' grand am gt1 sedan-  audiopipe ap-2002 amp and not sure of sub modelthey're 12's that came as package deal off ebay) Anyhow, I'm looking for that bass that messes with your breathing and all that, but don't wanna go broke doing it. I was considering an audiopipe txx-apx 15, after the answer I had just read, the way I understood it, is the sub is rated at 98.6 db, so  to achieve that db mark, I would have to push it with roughly 197 watts, but to get 3 more db out of it I would have to hit it with about 400 watts? Is that correct? And I was also wondering, if you have ever had to do research on this sub, will 1 produce the sound I'm looking for or will I need 2? And what type of box would you recommend I use? Thank you very much for your time in advance, its greatly appreciated!!!!!!

Answer
The box design is important. It must be optimized for the driver that goes into it.  Most driver manufacturers will give the design criteria or even a suggested box design for best results.  Manufacturers who do not provide this information are usually not serious makers.

There is a trade off between sensitivity and bandwidth for subwoofers (any speaker for that matter).  If you think about it, in order to get the resonance low enough to produce the true 20Hz stuff the mass of the cone must be heavier.  But, a heavy cone lowers the sensitivity.  So the tradeoff.  Light cones and coils make for high sensitivity but at the expense of the lower bass register.  

In any event, to get chest thumping sound you are going to have to sacrifice on sensitivity and push lots of power.  It is hard to get it on the cheap.  These monster systems you have seen at show car events which use a whole trunk full of amplifiers are doing just that; the subs are big heavy cones with 4 layer voice coils to handle the power and heat.  Your compromise will be somewhere less than that, but to get lots of low frequency energy there must be lots of extra power and bandwidth.  Think this way; going from a 40Hz, 110db level to a 20Hz, 110db level is one whole octave of improvement.  It will require triple or quadruple the compliments of the system.

Best wishes.