Passive vertical bi-amping with 440 Pro

[Soniclife]

Can you point me to some links that make a good case for biamping over bridging, last time I looked I never found any compelling arguments to try it, but I was just thinking yesterday that it would be interesting to try.

http://av2day.com/2014/05/vertical-bi-am...m-experts/

There is not much in that link discussing the difference between bi amping and bridging, only really the following bit..

"The result is an effective increase in the headroom that is greater than would be obtained by simply using a single amplifier of twice the power. In other words, a 40-watt per channel stereo amplifier will out perform, in a bi-amp configuration, an 80-watt mono amplifier driving all the drivers together."

It's not explained why this is, and I think it's wrong, but I'm no expert.