i been wantin to make a thread like this so fk it i am lol.... i started w/ this system ~10 months ago.. big difference between now and then.  1st was an splx15" and ss pca1000d:    136.8db still the same clarion deck..  added EQ w/ 7v out  got a bigger box maybe 3cubes  added a 4" aero.. this box and 4" port was the lowest hitting out of all the ones ive tried so far.   138.9db picked up a used 9515 and also swapped the pca1000 for the pca1500d   the splx was a loud sub.. the dd sounds alot nicer though sealed off the 4" hole on the front, added a side firing 6" flared port..    141.8db most recent mid/high amp, if you look at the pics i've been through 3 or 4 already.. this ones lasted a while though, i also had some pioneer 4x6 but they had to go, i cut the doors for 6.5 and have memphis coaxials for now.  found this already built at the local shop, its bout 5 cubes @ 45hz   nice ass/bracing shot  f'n mess  then most recent got a saz1500d and got rid of all the blocks and cleaned it up   143db i dont think it'll ever be done, though.