best 8 woofer for spl application

I have an '01 Nissan Frontier Crew Cab in which I have an approx 0.5cf per chamber enclosure mounted behind the rear seats. This enclosure houses two 8" subs. For power, I have an Audiobahn A8002T mounted neatly in the rear seatback, capable of 800 x 1 @ 4ohm mono, 400 x 2 @ 2ohm stereo or 200 x 2 @ 4 ohm stereo (audiobahn specs, up for debate). Nonetheless, there's enough to adequately power even the largest 8" subwoofers. I only have 4.25" depth to work with. I'm looking for SPL primarily, but need advice on choices for this 8" application. 8" certainly doesn't bring about a lot of options. Any suggestions? I currently have VERY early Diamond Audio 8" subs (don't recall the exact model #, but they're 4 ohm DVC), but one had been distorting horribly since I purchased it (used on Ebay). While they sound good and have decent SPL, I'm looking for something better. Any help would be greatly appreciated.

8-inch woofers will never get you into the realm of high SPL, but any of these would make a good-sounding system:  Tang BandSupport the12volt.com

Thanks for the suggestion, I've never heard of that brand. I know the limitations of 8" drivers, just trying to get the most out of the space I have.

I noticed that the mounting depth of the TB woofers are approx 0.5" past what my enclosure can accommodate. Would it be possible for me to fabricate mounting rings for these (to extend the depth another 1/2"). Would this be a bad idea?

Yes, very possible. No drawbacks, just make them out of a solid material and seal around the enclosure and driver mating surfaces really well. edit: Do you have the clearance to add mounting rings? Will add mounting rings put the woofer to close to a seat or other object as to muffle the sound or cause piston interference?What will you get for Christmas, bad boy? Coal........or Visonik?? - stevdart

Wow, is everyone clueless and lost in the dark? - uthinkuknoaudio

SPL and small sealed enclosure do not go together...your best bet is just some decent low end fill.

heavilymedicate wrote: Do you have the clearance to add mounting rings? Will add mounting rings put the woofer to close to a seat or other object as to muffle the sound or cause piston interference?

Thanks for the help. I believe there is additional clearance, though not much. Presently the current subs are pretty close to the seatback, but it doesn't seem to affect sound quality. I believe another 1/2" or so would be possible, and the 4.25" depth is an approximation (by the box builder) so depending on the motor structure, there may be a bit more leeway there as well. I have a CNC router at work that can machine mounting rings in no time. I suppose I could possibly remove some of the seat support (the metal grid that houses the foam behind the seat) if clearance is an issue. The seat is rarely used for anything other than for my 1 year old son. I was able to mount the amp inside this metal support "grid" tucked in the foam. I'll have to take pics sometime, as I believe with the available space this is a unique installation. I realize that 2 8" woofers will not compare in SPL compared to say 12" woofers in the rear seats (obscenely loud). I'm just trying to make the most of the available space, so woofers capable of producing the max SPL vs size are of importance. Thanks again everyone for the suggestions and help.