find someone with a probox near you and listen, it will smack you so hard you will pull the cash out and buy it off them. i hit 137.5 on my dash for a solid 2 years, i loved it but wanted legroom more than bass(i'm a bigger guy), but any properly setup ported system will work.
I hit 153.8 on my dash with a single 9512... =)
My next setup will be two 8s. Yes I said it. TWO 8" 1508s. Probably in a very small ported enclosure under or behind the rear seat in my crew cab. I bet you money it surprises people.
1969 Chevy RCLB C10 350/TH400 SOLD
2007 Chevy RCSB 4.8 4x4 LS SOLD
2008 Chevy RCSB 5.3 4x4 LT SOLD
2010 Chevy CCSB 6.2 4x4 LT SOLD
2005 GMC CCLB DRW 6.6 Duramax 4x4 191,000 and counting
2013 FORD CCSB F350 6.7 Powerstroke 4x4