Audio Systems: Horizontal Bi-amping, internal crossover, electronic crossover

Question
QUESTION: Hi,

I'm trying to connect two amps (Adcom GFA-500 and a Carver M-1) to my Legacy Signature Three's (bi-wired currently using the Carver.)  When I depress the Adcom 'power on' button a bizarre series of noises comes out of the speakers!  I'm simply using two Y plugs (one male, two female ends) to split the full frequency signal.  The Adcom is connected to the subwoofer posts (bottom +/- posts on the bottom of the speakers.)  the Carver is inline for the mids/treble.  Passive bi-amping it's called.  I'm using my tube preamp's tape loop inbetween  my Sirius radio and Sunfire Preamp (remote controlled.)  This sounds great as a tube buffer.  Output then to an Aux One input on the Sunfire.  The Sirius is connected inline to the tube preamp (the only line level source connected to the tube preamp.)  So where am I going wrong?  I would greatly appreciate any ideas in solving this problem!  Thank you.

ANSWER: Bi Wire and Bi Amp are two different things. Bi Wire is a recent convention reserved for performance equipmet(not professional) componentry. The only logic that I can apply to it is that their is far less resistance and therefore a better transfer of power to the speaker system.

You cannont connect two amplifiers on one speaker system, that essentially have a single internal crossover (even if there are more that two input terminals). The speaker must say that it can be bi amped. That means that there is no internal crossover and that the the two amplifiers will be connected directly to separate internal drivers and/or crossover. For example the tweeters and midrange can be internally crossed over and driven by one amplifier whose input is connected to the output of an electronic crossover which could have a setting to provide a Linkwitz Riley crossover point above 125 hz. Conversely the woofer is driven by an amlifier connected to the same electronic crossover sending a signal of everything below 125hz (typically 24db per octave)

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QUESTION: The Legacy speaker manual ENCOURAGES bi-amping this speaker.  Any thoughts? Thanks again!

Norm

Answer
Unless the Legacy speaker is set up for bi-amp (not bi-wire or horizonatal bi amp - not a technical term) you CAN NOT put 2 amplifiers accross the same load. The loads MUST BE COMPLETELY DIFFERENT. Amplifiers are not smart devices. There is no mechanism that tells them when a voltage appears at the output terminals that it will be protected against blowing out the output stage of one of the amplifiers. The power is meant to go to the speaker not back to the amplifier. There are ways to bridge amplifiers but you need to know what your doing and you need a rugged device that won't crack under the pressure.

I don't know how long Legacy has been around or what field experience they have, but I can tell you and you can read my credentials, that either you are misunderstanding what they are recommending or they need to have their heads examined