Bridging amps is a completely different thing. With bridging, 2 channels are summed into one, with double the power and double the noise and distortion. Not possible with any AVR that I know of, this is a feature limited to amps.
Bi-amping is the dividing of the audio signal into 2 channels, low freq into one and HF into the other. True bi-amping is usually accomplished with stand-alone active crossovers between a pre-amp and multiple amps. It also requires speakers that are specifically designed for this type operation. Many speakers offer "bi-wiring" type connections but are not actually set up for bi-amping internally with completely separate pathways for HF and LF inputs.
There are also examples of tri and quad amped speakers. In those cases the speaker either have no crossover internally, or have a very specialized crossover.
Many current AVRs offer a "bi-amp" feature that doesn't really fall into any of the above categories. It's not usually clear if the output from the 2 channels is crossed over into HF and LF components or if they simply output the same signal into 2 channels. Available power MAY be increased, depending on the total number of channels driven.
The major factor to consider is the speaker, not the AVR. Unless the speaker has completely separate internal pathways for HF and LF inputs, the benefits of bi-amping are small, if any.
With AVRs, the fewer the number of channels you drive with them, the more power is available to the channels that are driven. So simply using an external amp for some channels will greatly increase the power the AVR can provide to the remaining channels. The v665 can push close to 90 WPC if it's only driving 2 channels, but closer to 40-50 if driving 5 or 7. If you are driving 5 channels with the AVR and use the other 2 channels for bi-amping, you are actually decreasing the available power to each channel.
I use a v665 to drive only 2 surround channels and the rest go to an external amp.
Bi-amping is the dividing of the audio signal into 2 channels, low freq into one and HF into the other. True bi-amping is usually accomplished with stand-alone active crossovers between a pre-amp and multiple amps. It also requires speakers that are specifically designed for this type operation. Many speakers offer "bi-wiring" type connections but are not actually set up for bi-amping internally with completely separate pathways for HF and LF inputs.
There are also examples of tri and quad amped speakers. In those cases the speaker either have no crossover internally, or have a very specialized crossover.
Many current AVRs offer a "bi-amp" feature that doesn't really fall into any of the above categories. It's not usually clear if the output from the 2 channels is crossed over into HF and LF components or if they simply output the same signal into 2 channels. Available power MAY be increased, depending on the total number of channels driven.
The major factor to consider is the speaker, not the AVR. Unless the speaker has completely separate internal pathways for HF and LF inputs, the benefits of bi-amping are small, if any.
With AVRs, the fewer the number of channels you drive with them, the more power is available to the channels that are driven. So simply using an external amp for some channels will greatly increase the power the AVR can provide to the remaining channels. The v665 can push close to 90 WPC if it's only driving 2 channels, but closer to 40-50 if driving 5 or 7. If you are driving 5 channels with the AVR and use the other 2 channels for bi-amping, you are actually decreasing the available power to each channel.
I use a v665 to drive only 2 surround channels and the rest go to an external amp.
