Thanks Larryi - very much appreciate your comments!
Larryi -The best implementation of subwoofers I have heard involved using them at very low levels, setting the crossover point quite low, and using multiple subwoofers (easier to get smoother and uniform bass coverage). I think you are going in the right direction.
That's my direction. Fwiw - I still just can't believe the SPL's - room filling music I am getting out of just the 4 output tubes on the small RM10 and the Quad 57 without sub. Just looking to fill in the bottom. I have considered a few subs.
The Vandersteen 2wq was one I looked at. But I discovered that the signal needs to go through the Vandersteen crossover first. After the effort it took me to get to where I am with the RM10 / 57's; I am not prepared to let the Vandersteen crossover become the Alpha over the RM10. The Rhymik subs look interesting that Audiogoneer Bdp24 put me on. Then there is also JL audio and Rel. My understanding from another thread here is that REL went to China for manufacturing, and a new company MJ Acoustics is now their former staff in England.
The bigger constraint for me right now is our Canadian dollar against the US dollar. With the latest increase of interest rates in the US yesterday, they are now forecasting the Canadian dollar will fall to .70 cents in 2016. :^(
Buying anything from the US - 30 cents on the dollar, shipping, customs, 13% Canadian tax - ouch.
Two things about that room pic I uploaded - I kind of feel compelled to mention.
That house support pole. I wish there was a way to move it about 3 feet to the left. But once the music starts, it disappears anyway like magic.
The beige love couch on the left. I call it the break up couch. My wife can't stand it. We moved into a place together after about 1 year of dating. We actually broke up for two weeks 6 months after this. She left and took the living room couches. I bought that loveseat and matching couch. When she moved back I refused to sell them. Its something like 30 years old.