I'm kind of bewildered here, but why do you have black and red going into red and red?

Also, you seem to be using a speaker level switch with line level inputs, which is a recipe for problems.

Why not get something like the following? Plug into back of computer, then plug computer speakers into one of the two jacks and run a cord from the other into your amp. If necessary get a second jack that turns the 1/8 miniplug into two RCA jacks (on next page from link as CAT# AD-18)

Here is a link that might be useful: 1/8 splitter

A line-art diagram would be more helpful here. I suspect darwinsflinch is going from black to red because that's the color the manufacturer used. You can see the embossing on the back panel illustrates that he/she is connecting black to left and right to red consistently. I'm not sure what "braided" means, however. I'm not familiar with stereo or 2.1 setups that require a separate feed. I'm also not sure why it appears that he/she is connecting to one pair of speaker connections as an input. That certainly won't work.

I agree that the terminology is confusing. When darwinsflinch says "line", I think he/she means "cord" or "cable", not necessarily a line-level input.

darwinsflinch, more information, please?