It's a virtual guarantee that the salesperson at Tweeter will be clueless! The last one I encountered never heard of Linn, Meridian, Chord or even Arcam! I'm sure some exceptions occur. Buying anything from Tweeter/Ultimate Electronics/similar chain stores is GIGANTIC mistake. When enough people do it, high end audio will cease to exist. If you are setting up a purely HT system and aren't listening to music, almost any larger subwoofer will be adequate for room shaking duties. I suspect that if your subwoofer budget is $5,000 you can afford to trade with an audio dealer who can offer meaningful advice a properly demo equipment for you.