ok i got a 96 gmc with a box under the rear seat with 2 12 inch shallow mount punch P3s they are getting 500rms to each sub . would some poly fill help out. my subs sound great with songs with that nice low bass but some with tighter bass not so much. thanks
not knowing the voilume of your enclosure, it makes it difficult to determine whether you need polyfill or not. With that said.....Adding a heavy amount of polyfill will increase the volume the woofers see by about 10-15%....This may or may not make the woofers perform to your expectations.... If the box is ported....you have other issues that will need to be addressed.
its a sealed box not sure on the volume but it is one of those small boxes that fit under the rear seat . i am guessing 1.0 cubic ft . so a pound of fill per sub should work ?
I agree with Viking. If the box was built to Rockford specs....I dont think you need to add any polyfill. I have the same subs, but 10" and didnt add any polyfill, but I built the box to specs. So basically, if you built the box smaller than specs.....then a little polyfill would help.
As said, without knowing what you have and what is preferred, one can't give a real good prediction. But from what you say they are hitting deep which means good air space and on higher music you are probably hearing the subs ring. This is a sign of too small a box or no damping what so ever. I generally can't stand the sound of a an internally bare enclosure. One rule we do know is stuffing makes the sealed box act bigger, a little. Too much and it works against you. One pound per cubic foot is the rule of thumb when you know your figures. You don't so do .5-.75 pounds and make sure you tease it out real well. Just make sure it won't interfere with the back of the sub. You can try different amounts but I'm too lazy to remount my subs that many times. Just don't over do it. I usually feel my bass sounds much cleaner as it improves transient response and damping the reflections/ringing removes distortion. Good luck.
