Thanks for the advice guys! Based on this info, I'm looking at impedance-matching volume controls from Niles Audio, Russound, and Sylvania.
I like Niles and Sylvania because they have higher power-handling capability -- 100w RMS, 200W peak. Russound is 45/126. Does this difference matter when I have 6 speakers powered by 300watts, or 3 speakers powered by 125 watts?
I like Sylvania because it appears to have less bass roll-off -- they say they do 20hz-20khz +/- 1db, where Niles reports +/- 2db (Russound doesn't report this statistic).
So two questions:
1. Do I need to worry about getting the highest power rating I can?
2. Which of these three is likely to provide best sound?
Thanks,
Eric