I've been told the RCA and Cat-5 outputs can be used simultaneously, although I've personally never done it.

If you use the Cat-5 outputs, you'll also need a balanced line converter on the plasma's side. If you don't want to go with an RMC, the Audio Control boxes can also be used -- I've seen them work.

However, I've split the BIPAD8 RCA outputs before, and I'm pretty sure you'll have no problems going that route...

This will work beautifully. This is the stuff that remote microphone cables are made out of, and IF YOU HAVE GOOD GROUND ISOLATION (search the internet for articles by Bill Whitlock in re this) and you have proper impedances, you can go miles.

|I am

Use distribution amps.

|The time

To reach the 23rd floor (THE TWENTY-THIRD FLOOR ? ? ! ! ! ? ? ? ) from where? If it is anywhere more distant than, say, 21 or 25, then you had better be ready with ground isolation, very low source impedance, and, as I encourage above, shielding. Uhh, a distribution amp, and maybe even a very special one.

If I were to say "I don't think it is over-engineering," I would already have distribution amps and audio ground-isolating transformers. Don't depress your crew because your design does not work because the ground noise and distance difficulties were underestimated. I personally never ran more than 300 feet with 22 gauge individually shielded twisted pairs, but these were from microphones that were running around one millivolt (which means your signal will be WAY above that, so noise will not be as much of a problem in your design) and we had total signal isolation between the cable and the inputs to our preamp, call that mixer. At normal audio voltages, this cable should do your job easily, but the ground on one floor of a building is not at the same potential as the ground on another floor, rack-mount equipment tends to be connected to power ground, and transformers are mandatory.