OK guys, Let's assume that you have a 4 channel amp that gives you two 300 watts channels on bridge mode, for a 4 Ohms load.
At the same time you have a pair of 8 ohms speakers to hook up to this amp.
Let's say that you want to send 150 watts to each speakers, so you have two choices.

A- Bridge two channels of the amp at 300 Watts, and put the speakers in parallel. This will bring the total load to 4 Ohms in and each speaker gets 150 watts.

B - Bridge two pair of channels at 300 watts and put one speaker on each bridge side, so each speaker receives 150 watts.

Which of this two methods would be moe efficient regarding the amp overal performance (heat, power, etc)

 

Option B will be the least stressful on the amp but I would go with option A myself. The amp is designed to run at those specs so in order to optimize the setup, option A is the way to go. Plus it leaves 2 additional channels for more speakers.

 

My fairing and lids are ran like option A so i can have my B3 super tweeters on their own channels for EQing and gain control

 

I also want to say and im prob wrong here, if the speaker is 8ohm and u go with option B then the speaker will not get 150, but more likely around half that.

 

As long as each set of channels are set to the same voltage each 8 ohm speaker would get half of the bridged 4ohm wattage

 

Forgive my stupidity but if he is running this amp bridged then there are only two channels total, correct? If he puts the two 8ohm speakers on one channel then doesn't that only leave one channel for additional speakers not two?

 

If you're bridging a 4ch amp to run 2 8ohm speakers, and you're going to run them in parallel on the 2 channels that are bridged to get a 4ohm load, that leaves you 2 more channels to run other speakers.

 

running in that configuration presents a 3 channel output

 

I clearly do not understand this.

 

You're only bridging 2 channels which makes it 1 channel. Then you parallel the 2-8ohm speakers together on that bridged channel. Then you have 2 more channels which gives you 3 channels total like Yoop said.