Thanks for the reply. Are you saying it’s illegal, or it’s not a good idea? I know it’s not a good idea and that’s why I’m asking. I have hundreds of dollars invested in some very heavy gage speaker wire for several long runs and that’s why I need to know if it’ll be legal if I run it inside metal conduit.
It's against code. The reason however is for smoke toxicity. The in-wall rated cable has special jacket that will not produce noxious fumes when burned. Nothing to do whatsoever with electrical safety.
If you put it in metal conduit, you'll be fine and will be adhering to code.
I knew it was because of the fumes given off and that’s why I thought it would be ok running inside conduit. Just wanted to make sure it was legal. I know I can’t use it to go from one floor to the next no matter what.
Codes vary from jurisdiction to jurisdiction, so you might want to check with your local authorities. Who knows, it might be perfectly legal where you live. But I’ve also heard that it can be in insurance issue as well, something else you might want to check into.