Steve, your understanding is incorrect in part. As Andrew pointed out about a month ago, there is no "equal amplification" requirement. The max power ratings(if different amplifiers are being used for the back drivers and the fronts)can vary widely, as long as both are sufficient for the required sound levels. Andrew suggested that the amplification for the back drivers would be sufficient if it was about 60% of that available for the fronts. The important factor was that the gain(a fixed factor)was equal for the fronts and backs so the intended front/back balance could be maintained. This would be the case if a HT receiver or separate amplifier with identical channels(and say a 100 watt or more maximum output capacity)was used. If a setup with different amplifiers with different gains was used, some level control to correct for the different gains would have to be used.
