In my last house I had my subwoofer at the front of the room, plugged directly into the receiver with a one metre RCA cable. It just worked. In my new house, the lounge is set up as a proper home theatre room. There's a power point and sockets on the ceiling for a projector, and connections for rear and side speakers coming out of the walls at ceiling height. There is also a subwoofer connection running about seven metres to the back of the room, but this is not quite what I would have expected.I thought the best way to do this would be to have female RCA sockets on the faceplates on the front and back wall. I would use then standard RCA cables with male plugs on each end to connect the receiver to the front faceplate, and the rear faceplate to the sub. But there are male RCA plugs hanging out of the wall on about four inches of cable - not long enough to reach the receiver or the sub so I bought RCA "extension cables" with a plug on one end and a socket on the other, to connect the plugs to the receiver and sub. Also I'm used to RCA cables being shielded (a core with braided copper or aluminium foil shield wrapped around it, plus insulating layers) but the wiring in the walls is standard side-by-side/figure 8/tru-rip speaker cable.When I turn the sub on, there is a very noticeable low frequency hum that I didn't have in the old house. I've turned the sub volume down a bit from where it was so it's not too bad when there's a bit going on in the audio soundtrack, but before/after a film or during quiet passages it's quite annoying. I could move the sub back to the font of the room like it was in the old house, but I'd prefer to have it at the back if possible - it would mean rearranging a couple of other things as well. And I've tried giving the cable a bit of a tug and it's not moving, so I can't use it to pull a shielded cable through the walls - if I had a long enough shielded cable I'd have to run it along the floor around the edge of the room. What is most likely causing the hum? Could it be an electrical problem like a short or grounding issue? Is it likely the type of cable, or maybe the extra connections added with the "extension" cables? Or is it just the length? What is most likely to fix it? Or will I just have to move the sub?
↧