The weirdest audio video problem I have ever seen

[mikesiskav]

I was sitting on my couch yesterday and I noticed a feint, intermittent buzzing noise. The buzz seemed to come and go, lasting about 5 seconds each time. At first I wasn't sure where it was coming from. My TV and AV system were turned off (except the sub. I like to keep my subs always on). Thinking it might be the refrigerator, I walked over to the kitchen, but didn't hear anything except the normal hum of the fridge.

Coming back to the living room i poked my head around my speakers and TV and finally realized it was coming from my sub. I noticed that the buzzing noise was occurring at regular intervals. Using the stopwatch app on my phone, I found that the buzz would repeat precisely every 52 seconds and last for about 5 seconds. Disconnecting the RCA cable from the sub and disconnecting power from all my other AV equipment did not help. I hooked up my old Velodyne sub to the same electrical plug and it also made the exact same buzzing noise.

I was starting to get really perplexed. The only thing I could think of was to grab a 50 ft extension cord and try plugging the sub into other outlets in my house. I tried my office first, same noise. Then I tried my master bedroom. The noise was still there, although this time it was much lower in volume. At this point I started to think that something was causing interference in my power lines. I thought about buying a power conditioner, but most people do not recommend using them on subs. Besides, I didn't have this problem before, so why would it start just now?

Well, after a whole bunch more troubleshooting, I finally figured it out! I went to my breaker panel, and started turning off breakers one by one. I had everything off, except my living room and office (they are on the same circuit). The buzz was still there. Then I decided to turn off equipment in my office, starting with the Brothers laser printer. I went back to the sub and sure enough, the noise was gone! I sat there next to the sub for 5 minutes and it was totally silent.

The weird thing here is that I always leave my printer on, so why did it start causing electrical interference just now? Then I remembered that I had tried to print something yesterday but was out of paper. It wasn't that important, so I just forgot about it. My guess is that the printer was stuck in some sort of perpetual loop, trying to print every 52 seconds but unable to complete because there was no paper in the machine. I turned the printer back on, put some paper in it, and my subwoofer is now back to normal. What a relief! I thought I was going to go insane. It was either that, or live with a 50ft extension cable running to my bedroom.