I haven't seen too many reviews of these 6.5" subs through my google searching. I figured I'd post something so anybody else who might want to buy these subs and wants to know how they sound could read a quick review. I modeled a pair of these in a 1 cubic foot net box, tuned to 33hz. The final port was 2"x9"x40-3/4". I figured the 18" square inch port area would help with a lower tuning. No science to that decision, just a hunch. (I've attached a screen shot of the box and cut out sheet if anybody wants to duplicate this enclosure.)
How do they sound? To my ears, in my car, they balance depth, volume and accuracy better than any other sub I've owned. Even with a modest amount of power coming from my Fosgate Prime 750x1, these little suckers make me giggle with how loud they can get. Modern subs... it just blows me a way how loud a pair of 6.5" subs can get. Sound really smooth on any genre of music I throw at them. I mostly listen to EDM and hip-hop, but will throw in some alternative and country every once in awhile. Sound great no matter my mood. They only area I can honestly say they lack is on any type of kick drum. As to be expected, the small cone area just doesn't have the impact.
I would highly recommend these if you can find a deal on them, especially a pair. In my eyes, one of these would be too difficult to design a good ported box for. Fitting a port even tuned to 35-38hz would be difficult. Much easier to run a pair and get the benefit of the larger required net volume to fit a port.