My buddy has a similar issue with his sub. He uses his pre-amp to drive a sub whose name I can't remember. When I listened to it, I could hear vocals out of the sub. So I calibrated his sub and speakers and it sounded much better. But I could not get his sub to blend with his fronts the way my 600 blends with my 80s. The best way I can describe it is that the bass sounds distinct from the rest of the music. Now he doesn't perceive this and I certainly am not going to point it out since he's now a happy man.
