Cable splitting


I have a marantz 8802a feeding two lexicon Rx-7 amplifiers into a 7.2.4 system.  I recently learned after adding rear speakers that although the marantz has 13 channels of balanced outputs only 11 can be used at a time (seems very silly). I had been bi-amping my revel studio 2s but now cannot do that unless I have audioquest tether/split a pair of balanced cables for each channnel as the marantz makes you choose either bi amping the mains or having rear speakers for full atoms. Is there a downside to going this approach, e.g does the voltage signal drop, will noticeable noise be induced, etc.  I have Shunyata viper zitron power cables and defenders on 3 dedicated 20 amp outlets so I think the noise floor is already decent.  Thanks!
esthlos13
It’s probably not possible to predict with any kind of certainty what if any sonic downsides might result from doing that. In part because one of the key factors that is involved, the output impedance of the AV8802A, does not appear to be specified. And in part because the input impedance of the RX-7 is indicated as "minimum 10K ohms," which is rather low, and using a splitter to have a single output of the AV8802A drive two RX-7 inputs would result in the AV8802A seeing a load impedance equal to half of that value. And a load impedance of 5K is low enough to result in some degree of sonic compromise when driven by **some** preamps, AVRs, or other line-level components.

FWIW, though, given that the AV8802A is a solid state component, and therefore **probably** has an output impedance that is reasonably low, my guess is that there is a good chance it would work out ok.

Also, rather than using an Audioquest splitter cable, you might want to consider using one of these relatively inexpensive balanced y-cables, that are typically used in pro audio applications.

Regards,
-- Al

I don’t know about the Marantz, but I have not had good results with the "bi-amping" options in these processors. Most of the time, they do not truly output the same signal on both "biamp outputs". They have a circuit that examines the actual waveform used by the main outputs and then sends it through a "comparator" circuit to subtract those waveforms. It then takes the difference and send it to the optional "bi-amp output". The result is highly reduced sound quality. It is much better to use a splitter Y-cable. However, you could possibly have other problems to deal with like almarg suggested (mixing input impedances of multiple amp channels). This can also result in reduced sound quality (weak bass, other). It may be just better not to biamp at all and run the speakers from one amp channel.

If you really want to do a bi-amp splitter cable, you can look at this one, in addition to almarg’s suggestions:

http://audiosensibility.com/blog/products-2/specialty-cables-occ-copper-and-occ-silver/#!/Impact-SE-XLR-Splitter-Cable/p/39328518/category=5528439

It’s very high quality OCC copper, but it does use the silver-plated Neutrik XLR connectors, so keep that in mind if you are looking for a particular sonic signature.