The 5.1 speakers I just received were FREE, so don't laugh. The satellites are all the same (2.25"). I have no idea what the frequency response on any of them are. I have a Yamaha HTR 5830 receiver with a fixed sub crossover at 90. I have a Yamaha YST SW215 sub that I have the crossover set at max to allow the receiver to handle bass management. I admit the satellites are cheap, but I put on "Saving Private Ryan" and it was awesome. My windows where shaking. Do you experts have any tweaking ideas on the satellites and sub? 2 satellites at ear level on each side of a 27" Sony Vega 8.5 ft away. (TV is 3 ft off the floor) Center channel just above the TV, 9 ft away. 2 surrounds about 6 inches behind on the sides 4ft away, ear level, facing listening position. Sub is on the floor to the left of TV, toed in a bit.