Well I was in the same situation. I used to do competitions, mostly local car show ones. But everytime or almost everytime I would be the one impressing everyone else. I have had cars do up to 156dbs on the ac/190 and loudest I got was in a trunk with a custom ported rear deck on the TL was 153.4. I have been doing demo cars for a couple of different stereo shops as well. I have used subs such as
Kove-Armagedon M series,z series,and the uberwoofer the u2 series
MTX-5000,8000,and the 9500's, which was the loudest to date for me.
Audiopipe-Yes cheap subs but did a 149.2 with 4 of them,on the tl to boot.
Audiocraps-Got loud but sounded horriable
Orion-xtr's,cobalts
Rockford Fosgate-Old series 1's(lol)
Soundstream-very good subs,older ones and cant remember model.
Lanzar-xmax,heritage(not bad cheap subs believe it or not)
Alpine-type R's( I have these now, 2 of them)
Well most of those cheaper subs was when I first got into car audio back in the day. It was a bug and just keep getting more and more expensive. Those Kove armegdon u2 subs were 800 a piece brand new msrp. I paid 400 for each. Never again I say after having my alpine type R's.
I found that it dosent take thousands and thousands of dollars to sound good and get loud. I have my alpines in a sealed enclousere and have to say they are the best woofer on the market for the price. I have hit 144.3 on the 190 a/c and 140.2 on the tl on the dash. Just wanted to let you new guys know that these are some great subs for the money. Are there better? Of course there is. But for the 115 bucks you can get them off the net then no there isnt. I could list alot of subs out there that will get louder and sound better but they will be alot more money, then again there are alot of subs out there that are highly overpriced that sound nothing like the type r. So it just all depends. Also I know everything is install dependent, but I have mine in the most basic install with no upgrading of the electrical system, which I need to do one day, but have to see these subs impress me. I will make a seperate box for ported when I run the local comps next summer. I cant wait to see what kind of numbers I get then. Peace!