I'm not sure where to put this thread so, I threw it in here.
My Uncle is having a lot of landscape work done including landscape lighting and outdoor speakers. We've been talking about it since I'm doing similar projects.
Anyways, he has a contractor running his cables and such. I was talking to him earlier and he told me how his contractor is using three-wire direct burial cable for his speakers. He is going to use two of the wires as 'positives" on a left and right and use the third wire for the common ground for both. The argument is that he only has to run a single cable.
I argued with him that he's not really saving much money by not buying two separate speaker wires, since the ditch is being dug anyways and you're not talking that much more money for supplies. The run to one speaker is about 80' and the other is 100' with 20' separating them. He said it's being done tomorrow and that the only speaker wire he can get today would be pricey and that it would also require the cost of conduit. Plus, his contractor is giving him the direct burial wire they are using.
I told him that you shouldn't use the same common for both speakers. He asked me why, and then I realized that I didn't know. It's just something that I've been told. I don't know if it puts more of a load on the amp or if it's an ohm issue or what.
I'm worried that if he goes this route, he'll either ruin his speakers and/or his amp.
Can somebody fill me in on this before lunch time tomorrow?
Am I wrong about this? If not, can you clue me into the problem so I can inform him with the reason and not just what I'm guessing?
I've been doing a Google search without luck.