Are Xtant subs any good?

I couldn't tell ya neva really seen many people wt them so i wouldn't guess soo, the cheap people are buying RE and Ed and the rich folk are buying JL, so pick and choose.. BUt remember it's all in the install.

those are the 6 sided subs correct?

if so i've never heard them myself but have heard from a few owners that have been very pleased w/ the subs...but they also metioned that they had great sq.....and weren't spl subs (if there is such a thing //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif )

I have heard them a few times, but have also read a handful of happy Xtant users, for daily SQL purposes they seem to be great

Xtant subs sound good and look good, however you're not going to win any SPL contests with them. With a maximun excursion around 13-14mm for the X series, you're not gonna hit 150 unless you use alot. If you just wanna bump around town, go ahead. You can get Fosgate, RE, JL, or Kicker to outperform them around the same price. I use one 15", I like it but I got a good deal ($85) and I'm still looking for a replacement as we speak (JBL GTI W15).