-The gain on an amp is NOT a volume ****. It is a gain. Set it correctly with a voltage meter or with some bass heavy music you know really well.
-I dont know what the brand is at walmart but it will be called polyfill or pillow stuffing. Depending on who you're talking to, they'll know one of those.
-Though polyfill does take up space, it makes the speed of sound lower, so the wave reflections are more delayed. Also, it makes the wave reflections "quieter" because it takes sound energy and turns it into heat and motion. In smaller set ups, sometimes you hear no difference. Sometimes it makes a HUGE difference. It's all application dependent. However, for a couple dollars it's worth a try.
2000 Mazda B3000 TL Edition 2wd
-Gibson Exhaust- -Gangsta' Tint- -31" A/T's- -2 15" SI Mags- -Sundown SAZ-1500D- -LSD- -Torsion Bars Maxed-
*Eventually: Head Lights, More Tint, 5.0 swap, Murdered, Tube Bumpers, Off Road Lights, Body Lift, Better Stereo, More...