Bi-Amping questions [Archive] - Audio & Video Forums


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09-07-2006, 08:06 PM
Here is the background info. I have a Harman Kardon AVR525 with 6 speakers and 1 sub hooked up to it. The 6th speaker is used in a different room with the multiroom function. So in effect, there is one unused amp in the receiver. The extra speaker in the other room is a Klipsch Rb-35 which is capable of being bi-wired/amped. I am not sure what the technical term is for the little clip that would be used when NOT bi-wiring/amping, but my question is would it be advisable/possible to attach both the surround back left/surround back right wires from the receiver to the speaker WHILE that clip is in place? If I attached the cables while the clip is not in place, then I'd be sending the right channel to the tweeter and left channel to the woofer. If I attached the cables while the clip is in place then I'd theoretically be getting twice the power to both the tweeter and speaker AND both SBL and SBR signals would be fed into a single speaker, but I'm not sure of whether or not this would harm my system in anyway. Thanks guys!

09-07-2006, 10:23 PM
Never short any two amplifier channel outputs together, it will damage the amplifier or at least cause the protection circuit to shut down that channel or the whole amp.

Amplifier outputs are voltage sources; if the two channels are attempting to acheive a different signal at any time, very high currents will flow while each voltage source attempts to force the output to match the wanted instantaneous voltage for that channel.

For some decoding schemes right and left rear have identical signals, but for others they do not. Even with identical signals, if one output was set 1dB higher than the other the same problem would occur.

Unless your amplifier has bridged outputs, there is a simple way to sum two channels into one speaker using a 48VAC center tapped transformer. Connect the ground leads of both channels and the minus lead of the one speaker together. Now hook the hot lead of one channel to one end of the 48V winding and the other channel hot lead to the other end of the 48V winding. Connect the transformer center tap to the other(positive) speaker lead. Do not allow the 110VAC primary leads to touch each other or any other connection. The transformer shoud be rated at probably 50-100 Volt-amps.

09-08-2006, 03:08 PM
I have the AVR 635. If you are using the Multi Room function, it takes both the left and right Rear Surround channels and isolates them for Multi. I doubt your system configures this any differently so that last unused channel should be the other half of stereo in your other room.