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What’s the Right Power Amp Ratio For Bi-Amping?

Is there a “golden rule” or rule of thumb when selecting amplifier power in a bi-amp setup? It seems to me that the power should be apportioned according to the demands. Since most of the energy consumption  in sound reproduction is by lows, it stands to reason I should use a much more powerful amplifier for lows than highs, but what ratio of power? 2:1? 10:1? Is there a wrong answer?
128x128sleepwalker65
vinylfan62
119 posts
 
It doesn’t sound like you are getting advice from anyone who has tried bi- amping. I have. First-You just need to try it and see if it sounds good to you. No rules will help guide you in my opinion.  I use two Bedini class A amps to bi-amp. The 25 watt is used for mids and tweeters. The 100 watt is used for woofers. These are excellent sounding amps individually. Bi-amped gives an amazing  improvement. I’ve used them successfully with passive and active crossovers. Fire up the amps you were thinking of using. You can’t hurt anything if you don’t drive the speakers into distortion. 
carbide
4 posts
 
I believe the "gain" needs to be the same.
carbide
4 posts
 
Check out ask Paul on utube. (from ps audio)
unsound
7,329 posts
 

If the woofers are closer to the floor (as they typically are) you'll probably get some room gain there, so that might need to be considered as well.

The cross-overs can play quite a part in this, just think of how much overlap there can be with 1st order cross-overs. The least complicated way to do this is with identical amps.

gregdude
222 posts
 
I think the OP is asking about the brain's perception of lower frequencies. If I'm correct what the OP really wants to know is how much more SPL does a low frequency tone require to be perceived as equal to a relatively higher frequency tone. I don't have an answer to that but I've had good luck feeding my lower frequencies around 5x to 8x the watts of the higher ones. I use towers that have an active bass section and dsp. My amp is 50 wpc and the bass is a few hundred wpc. 
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