bi-amping question

nastynice

sorry if this has been covered already, I tried searching the term bi amp but it wouldnt let me, and bi-amp but nothing came up

I've never heard of "biamping" until a few days ago, so I'm not too familiar with it. I understand the process and the reasoning behind it, but one thing I dont get is how could the same speaker all of a sudden handle twice the power going to it? More specifically, the tweeter on its own handling the amount of power that the speaker as a whole was getting before?

To be more exact, I got a pair of monitor 40's and theyre rated up to 125 watts rms. Feeding this with an onkyo rated at 85 watts per channel, so if I bi amp it that means i'm giving the speakers 170 watts rms each. As far as I know, sounds like this is something I shouldn't do, as it may damage the speaker. I feel like 85 watts going straight to the tweeter might be overkill. Any knowledge on the subject is greatly appreciated...

John K.

Nasty, welcome to Club Polk. Yes, this topic has been covered numerous times. The first point is that despite advertising claims for some receivers, they have no capability to actually bi-amp speakers. They have just one main power supply section which is distributed through several channels of output transistors, which have no power of their own, but simply act as valves in giving each speaker driver the required amount of power at a given moment in time. The maximum amount of power which can be supplied isn't doubled or increased by any amount when it's distributed through two sets of output transistors(one set previously not being used for back surround speakers)rather than one; the speaker gets the same amount of power needed for the sound level at that instant, no more and no less.

As to the actual amount of that power, at a comfortably loud average listening level in the 80s of decibels, it's about 1 watt for Polk and other fine quality speakers of average sensitivity. You can't "give" a speaker more power simply by connecting an amplifier that has a higher maximum output rating; if 1 watt is needed at a particular moment, that's all that it gets, regardless of whether it's a 10 watt amplifier or a 1000 watt amplifier. So no, there's no danger in using a receiver or separate amplifier with a higher power rating , unless you'd try to play at an extremely loud level, and then the more significant danger would be to your hearing. Of course, brief split-second peaks in some material with a wide dynamic range, such as some classical compositions, require much more power for that instant, but typical receivers with ratings anywhere in the 100 watt area, such as your 85 watt unit, have enough capacity for these moments in ordinary home listening situations. No need to be looking for more maximum power, especially by way of a useless receiver "bi-amping" procedure.

nastynice

thanks john.

I've also read that biamping or biwiring gives the speaker better sound quality, something about signals not being mixed for the different frequency ranges. Doesn't seem to make sense since the signal goes thru a crossover in the speaker anyway, but is there any truth to that?

John K.

No, you're correct; it doesn't make any sense, but it's one of the many audio mythologies which continue to float around, despite the lack of factual support. Different frequency ranges are mixed at all times, from the original performance, throughout the recording process, in the amplifier, and only are separated after passing through the speaker crossover. Comments I've read about "powerful" bass frequencies beating up "delicate" treble frequencies indicate either a lack of knowledge of basic principles of audio technology or a lack of credibility.