do they just ad more power to the fronts some how? like run the left and right from your reg 5.1 amp or 6.1 amp into it and then it boosts the power and send it back out as 2 channels again?
so like lets say you have a 80 watt yamaha 6.1 and you want more power for the fronts. you could run a 80 x 2 integrated amp and get 160 watts a channel for the fronts?