I'm searching all over for info, and someone here might be able to help me
get an answer or idea. A few companies are selling whole-house sound systems
that place standard line-level audio --unbalanced-- onto unshielded twisted
pair CAT-5e/6 cables. They (the manufacturers) say this works fine up to a
couple hundred feet.

I can't find any reason this should work. In fact, as I search the web for a
rationale, I fine lots of examples where balanced signals are used on CAT
5/6, which makes good sense. Using unshielded cable makes me wonder, but
that can wait a moment. I can't find anything anywhere that says unbalanced
audio is OK on UTP cable.

Does anybody know of some documentation on this subject, or do any of you
have any experience with unbalanced line-level on UTP?

-Thanks!

-John O
Heathkit Educational Systems
(yes, *that* Heathkit!)