Paul,
Large room - yes.
But not enough oomph with that gear!? What did you do? Treat all the room's surfaces with 6 inches of batting?

I'm a fan of multiple subwoofers. Four's the magic number in my books. So since this is an Outlaw forum, let me first suggest that you add three LFM-1's - if you are looking to spend all $1500 (or so).
If you want to spend all $1500 on one additional sub, then why not go back to Def Tech?
As for the "lack of audition" situation, I take it that you can't get to a dealer to check it out beforehand - or that no dealer will alow you to test drive one in your home. Too bad because my local Def Tech dealer would. Perhaps another reason to try Outlaw.
And since Velodyne is my favourite sub manufacturer, I gotta suggest that you check out their product line as well. See how much $1500 will buy from them.
But I really have to believe that adding three LFM-1's would definitely solve that lack of oomph!
Jeff Mackwood
ps. I know this may sound stupid, and I don't want to insult your intelligence, but I'm still puzzled as to why something is lacking with your current gear. Could you perhaps have a phase problem between speakers that's doing some serious bass cancellation at your listening position? Poor accoustics? Some medical condition that doesn't allow you to feel vibrations when the whole world around you is vibrating?
