As the title states, can 5.1 surround be carried over composite cables? I know it seems like an easy question, but I'm not 100% sure on the answer.

Composite refers to a video cable which doesn't carry audio.

Analog audio (red/white) carry "stereo" (right/left) audio only. Although, it can be fed to a receiver that has Dobly Pro-Logic and can provide a surround effect.

For the best results and attaining "discrete" 5.1 surround (Dolby Digital/DTS), you will need optical or digital coax. And... obvoiusly a receiver that supports DD/DTS.

sometimes with a well constructed "composite" cable (the yellow of your assumed red/white/yellow bundled cable) you can use it for a digital coax feed - but you should really try for an rg59/rg6 connection.

As the title states, can 5.1 surround be carried over composite cables? I know it seems like an easy question, but I'm not 100% sure on the answer.

Yes, but it is no longer refered to as "composite" when used for audio, but rather "coaxial" digital cable [SPDIF] which can carry "lossy" Dolby Digital, and DTS multichannel tracks, or 2 ch. PCM [CD].

As the title states, can 5.1 surround be carried over composite cables? I know it seems like an easy question, but I'm not 100% sure on the answer.

Absolutely... just not at the same time as a video signal.

No one's even sure what the OP is asking, here. :confused:

Well in this case you should go optical but yes the yellow wire(if a good quality) can carry a good signal thru the digital coax out and in.