Need help from smart people - biamping


Hi, I know some of you are electrical engineers or just knowledgeable - looking for your input. I'm looking at the option of bi-amping my speakers. One amp on the mid-tweet connection and an identical amp on the bass connection. Speakers are B&W N804s. Question is, if you do this do the two amps react to the loads as one amp would, or is it possible that if the two connections (drivers) have different impedences, the bass might be louder relative to the mid-tweet, or quieter? In other words, if the upper end has impedence of 8 Ohms and the amp puts out 100 w/ch at 8 ohms, and the lower end is at 4 ohms, and the amp 200 w/ch at 4 ohms, will this result in a problem in the resulting aural output than would have been experience with a single amp? Thank you.
jimmy2615
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I concur with Meiwan's doubt. Tried it with three times with three different amps and never thought there was any real improvement. Different speakers were used also.
If the upper end has impedence of 8 Ohms and the amp puts out 100 w/ch at 8 ohms, and the lower end is at 4 ohms, and the amp 200 w/ch at 4 ohms, will this result in a problem in the resulting aural output than would have been experience with a single amp?
No, that won't result in a problem. The proportion between the amount of current and power drawn by the speaker at high and low frequencies in response to a given amplifier output signal voltage will be the same regardless of whether the current and power required at each of those frequencies are provided by the same amplifier or similar separate amplifiers. This assumes, of course, that identical signals are provided to the inputs of both amplifiers, and that the amplifiers are either identical or their gains are matched in some way.

If you do end up biamping, since you would be using two identical amplifiers you may want to also try a "vertical" configuration, in which the two channels of one amplifier drive the high frequency and low frequency sections of a single speaker, respectively, and the two channels of the other amplifier drive the high frequency and low frequency sections of the other speaker, respectively. Compared to the "horizontal" biamp configuration you are proposing, the vertical approach would have the advantage of having the same signal going through both channels of a given amplifier, potentially reducing interchannel crosstalk.

In general, though, I agree with the others that simpler is usually better, and that a single higher-powered amp will often be a better solution.

Regards,
-- Al
here's some more info for you re. biamping
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1274907651&openflup&4&4#4

i like Eldartford's phrase that this should be called "dual amping" because biamping means something different (where you gut the speaker's internal x-overs & use an external x-over to split the frequency spectrum & pass on only that portion of the freq spectrum that the driver is capable of handling).

And, back in Jan 2012, we discussed this bi-amping thread, which you should read (skip over the bickering, please):
http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1326877788