subwoofer 19 by 18 room


I am building a 5.1 home theatre
have an Arcam 350 on the way and am using B&W Matrix twos, center and 301's in the rear

I've a bit stumped on subwoofer
everything I demo is too loud, rolled wrong and it sounds like a booming box

Definitive, B&W, Martin Logan didn't excite me
Paradign sounded okay, heard stay away from Velodyne (but I was impressed with them 20 years ago)

any suggestions for a single unit subwoofer?
probably need some eq in my near square room

I may even have Jim Salk build me something

ps I have a two channel room where I do my serious listening to music
128x128audiotomb
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"honestly the signal from my two front channels will mostly be absorbed by the couch"

No this won't compute much here. Bass modes will still abound, even with the largest of couch and furniture infront of the speakers, regardless of what speakers the bass is coming from. The room modes will still excite, and be audible.

"open ended on three corners I doubt the room modes will be that severe"

Doubt? Yeah, if you get in there an measure (and listen) through the frequency sweeps, you'll be able to tell where you're at--which is the only way to tell. Yes, possibly, depending on seating arangmenents, you may or may not be able to get away with good fidelity and smooth response, in some possitions. But you gotta measure and test to find out, yes.
I've not seen the room, but Know from experience what usually ends up is modal problems at certain points, regardless of how open the room is. I hope it works out very well for you however.
I recently did a lawyers home theater in the main living room, that was open on both sides of the listening space, and the room was 21feet deep x over 33 feet wide (43 in once spot)to the open spaces, with a 10-11 foot tiered/coffered ceiling. After running through all the test frequencies, and test material, the owner strongly concured that we needed another pre/pro in his system--one that had a parametric EQ built in, at the time. Problems solved, the 3 main bass mode problems were eliminated (over 20db boost at two frequencies!!!!!...bombastic to say the least!!!!...not hi-fidelity).
Anyway, it's always a consideration. Nonetheless, I do hope you get better results with your Arcam option, if you go that route
The best of the best of the A$$ KICKIN BEST subwoofer you will ever get PERIOD- JL Audio f113
http://home.jlaudio.com/products_subs.php?prod_id=371

I have tried them all and this is the most bang for the buck and musical too- I just bought my 2nd one
Read what Larry Greenhill from Sterophile had to say about 2 of these bad boys with 1 I was in bass haven but 2 well we will see tomorrow
Good luck
everything I demo is too loud, rolled wrong and it sounds like a booming box

What is your budget...accurate extreme LF does not come cheap. I am hardly shocked at what you describe....if you are looking in the wrong price range.

The Velodyne DD 12 suggestion is a good one...15 would be better.