Originally Posted by larkowski1
Passive biamping is (IMO) a waste of electricity and at worst can deprive the other channels since most (all?) AV receivers are limited by their single power supply. Almost all receivers can deliver more power in stereo mode, less in 5 channel mode, and even less in 7. I figure turn off the channels if you aren't really using them.
I do not believe that bi-amping cuts your power in any way. The fact is, that in the absolute majority of receivers and amplifiers the output per channel
is higher is stereo mode, and lower in 5- channel ( even lower in 7 channel mode). However, the reasons for such behaviour might not be explained well.
1. The power supply is not sufficient. i.e. all the power amplifiers draw power from the same transformer. As you increase number of active channels, they start to compete for power from the transformer and the output per channel drops
because there is not enough juice for all the channels.
2. Not optimal loading of power supply. This is a little trickier to explain, but it is a factor.
In the case of bi-amp, you do not fully use the power of both channels, you just distribute the load between two channels. Thus, it should not be a problem. On the other hand, you gain very little too, since the main advantage of true bi-amp is getting rid off passive filters in the speakers.