it's ok actually. But just OK. I actually have my subsonic set at around 28hz right now, because the MTX has never liked going too low, it gets a little stinkage after a few minutes playing really low notes, but what do I expect, the Fs is 36.4hz. We're going to redo it sometime in the spring, add some more power, another 1500d, and most likely a TC Sounds LMS 5400 12" woofer, and see what we can really do with a single 12" woofer. I like the MTX 9500, but it seems that it's sweet spot is from 30-40hz no matter what box it's in.
I really want to see what it'll do full out, but on certain notes at high volume, my headunit shuts off and then comes back on. I think something's loose inside of it, because from what I've heard Eclipse headunits don't skip very easily, and even if it did, it shouldn't shut all the way off, then power back up.
Off Topic now, but how do you like those RL-i 8's? I picked up 4 of them for another build that's going to be upcoming, and was thinking about running a Zapco Reference 1100.1 to them in a true SQ setup.