One of the guys here has the Alphasonik subs/amp, sounds pretty good actually, don't know that it's a high-end brand though. I would think Audiobahn is the high end brand and Alphasonik is the lower end brand.
I used to use alphasonik amps when I first got into car audio, like 10+ years ago. I felt they were one of the better low priced companies back then. I haven't listened to their new stuff though. I think CA&E reviewed one of their subs earlier this year and they liked it for the price if I remember correctly.