5.1 Analog (6 RCA jacks) Splitter Box ???

[par4ken]

I just bought two of those at WalMart.

Does anyone know if the composite connection can be used for a third audio signal?

Yes

 

[par4ken]

Those into DIY could do what I've done for years that is build a multichannel mixer. No switching required whatever source you are playing goes straight through the system. You can even act as a DJ by fading in one source over top of another. One possible drawback of this idea is that you could possibly pickup extra noise or hum from the unused connected cables and equipment, but I've never found that to be a problem. You eliminate extra switch contacts this way as well.

My system was four channel from the start. When I ran into a DVD audio disc that wouldn't downmix to four channel (I still don't know why ) I added an extra input feeding centre to the front channels only. I included a pot to adjust the level as required. I didn't need that extra input again for years until I found that SACD's are only downmixed if converted to PCM by the Oppo. Hooking up an extra cable to the Oppo I can now play those 5.1 discs without the need to premix them beforehand. I could/might add another input for the lfe channel but not sure if that's really necessary.