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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?
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Showing 2 responses by bdp24

bdp24's avatar
bdp24
9,504 posts
 
@vinylfan62, actually, I have bi-amped, in the past (first time in 1972) and currently. It's nice that your Bedini 25/25 (I ran one for years with my old QUAD ESL's) and 100/100 work great for you (knowing Bedini, they probably have the same gain), but the pairing of a 25w amp with a 100w may or may not work with anyone else's loudspeaker. They certainly wouldn't with my Magneplanar Tympani T-IVa's!
bdp24's avatar
bdp24
9,504 posts
 
It depends on the design of the loudspeaker. It is my understanding that Magnepan recommended the two power amps used to bi-amp their old Tympani T-IVa be of equal power rating (and gain, of course), and chose the speaker’s cross-over frequencies (low pass: 3rd order @250Hz, high pass: 2nd order @400Hz) partly in relation to the speaker’s power "center" (the frequency at which equal amounts of power would be required to achieve the same SPL on each side of the x/o frequency created by the above two filters).
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