idrgbdy
+1y
a 10" sub will probably be cleaner sound, but the 12" will give more bass. memphis makes some good speakers. in my opinion, and what i hook up in my rides, is a dual 4 ohm voice coil 12" sub (somewhere around 300-500w rms, and 800-1000w max). run the sub parallel with a 800-1000w max 2 ohm stable mono channel amp.
if space is an issue, just use a 10". if space is really tight, get one of those new 1000w pioneer subs that are 3" thick. lol