Quad 57's stacked with Gradient sub woofer

When I had stacked 57s, I used Maggie bass panels with them and later Entec subs, the Maggies were indeed a great improvement, as well as the Entecs, which I placed away from the Quads. Later I used Entecs with the 63s. In both cases, having a better low end foundation was indeed a big inprovrement no matter what kind of music I listend to. I would run the stacked 57 without the x-over, letting them run free and blend in the Gradients very carefully by ear, using the x-over. I would start off by placing them under the 57 stack and then experiment. There is a good chance that you will like them placed that way, but I would certainly try other placements as well. Once they are properly blended in, you will probably never wish to do without them. What amplification are you using with this setup?
Cheers,

As long as you understand that the Gradients are WOOFERS not subwoofers you'll be satisfied by their performance.

They were designed to be used as bases and work very nicely that way for a single pair of Quads.

Stacked Quads? You may get better performance from a single set and the Gradient. Stacked Quads only buy you more dynamic headroom at the expense of imaging and room placement flexibility. With the right amps I never felt that the Quad 57's needed more radiating area so the need to stack them was moot. YMMV...

Sorry for the off-topic question, but you guys seem to be Quad experts. Do you think an 11x15 room is too small for the Quad 57?