Ayo,
Sup to everyone who knows me and sup to those who don't.
I got a Brahma 15 in the back of my car right now hooked up to a Hifonics BX1500D (500Wx1 @ 4-ohms, 1000W @ 2-ohms, 1500W @ 1-ohm).
I want something smaller. Not to complain about the Brahma. It's still in great shape and sounds...
Have you tried hooking them up to a different amp? What amp are you using?
Are you 100% sure you're wiring them up correctly to deduce that 8 ohms is louder than 2? That doesn't make any sense to me unless the amp is not 2-ohm stable.
Try hooking them up to one of your buddies' amps.
"This has a noticable effect, and I would recommend the 9811 over the cheaper 9807 for this feature alone." This quote is from http://www.carreview.com/CD,Receivers/Alpine,CDA-9811/PRD_174027_2861crx.aspx
The 9807 is more expensive, packerfan?
I would go with the Alpine. I personally prefer...
out of the three I've heard, the perfect, the diamond, and the alpine, I would go with the perfect. The alpine is decent, the diamond is better, but the perfect is the best. That's without considering prices. IMO too.