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Splitting a balanced signal ???

I'm in the process of making up some new cables for my HT system and ran into a bit of a dilemma. My surround processor has one balanced output for a sub along with three individual RCA outputs for multiple subs. I was told by the factory that all jacks are wired in parallel and active at all times, so i'm not stuck with choosing one over the other.

My problem is that i am running the mains, center and surrounds in balanced mode. In order to keep the gains even ( balanced typically is higher gain ), i was planning on running the subs off the one balanced output and simply splitting it between two cables. If this is going to create an impedance based problem, i can simply keep the subs on RCA's and play with the output levels in the processor. Obviously though, i would prefer to stay balanced if possible.

Anyone ever try something like this ? If so, what were your results ? I haven't checked, but are there "T" or "Y" adapters for this type of situation ? While i don't think that crosstalk between the two connections would be a big deal as we are strictly talking very low frequencies and a mono signal, i'd like to hear others thoughts and / or experiences on this. Sean
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sean
twl
3,251 posts
 
Dean, I concur with ljgj. The pro sound guys do it all the time. If you go to a pro musician's shop, they should get you going with the right hardware.
sean OP
6,231 posts
 
Thanks for the responses. Clueless brings up an EXCELLENT point that i had not thought of recently since i haven't had to deal with such things. As such, i'm extremely glad that he did. It may have saved someone a major repair bill, me included. This may even be related to the problems that he experienced.

Part of the problem with balanced products is that there is no set standard in HOME audio products as to which pin carries what specific part of the signal. Most professional gear follows one industry standard. You have to remember that you have THREE different signals in a balanced cable, not just two. Since there is a lot more involved than just hooking up a two wire cable out of phase, there is more that can go wrong.

As such, one can simply connect Component A from Scamco International to Component B made by Hype Electronics using standard balanced cables and have instant compatibility problems. This is not to mention the potential for actual damage that could occur.

This happens because one manufacturer uses a different wiring pin-out for their balanced jacks and the other manufacturer uses a different scheme. As such, the source supplying the voltages would be connected to the wrong pins of the other component. This could result in short circuits, damaged input or output circuitry, etc...

With that in mind, one should NOT take for granted that "balanced is balanced" and just hook things up. There are different wiring patterns. That is why John Atkinson specifically mentions the pin-out on various balanced products that they test and review. If in doubt, contact the manufacturers of each component being hooked together and record their pin configurations for future use. I would think that most owners manuals might include this info, but as we've seen, some "manuals" are simply a useless photo-copied piece of paper. Sean
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dollysowner
47 posts
 
I don't know about consumer audio equipment, but all pro audio equipment uses pin 1 as ground. Where the issue becomes interesting is that most, but not all, manufacturers use pin 2 as high and pin 3 as low; on the other hand, a lot of old pro recording gear (e.g. Ampex recorders, Dolby decoders), used pin 3 as high. You probably won't mess anything up by connecting them together, but if you find a compatibility problem, you may have to rewire one set of leads.
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