Interference through speakers

[TLS Guy]

Also, most RF sources are in the Megahertz frequency range which you can't hear and your speaker cannot reproduce.

That point is not correct. The RF picked up by the speaker cables can and often is detected and rectified by the early stages and amplified as audio frequency interference. This is just like a radio detecting RF and producing an audio signal. It gets to these high gain stages through the negative feedback loop.

One other point, many dimmers are not off when the lights are off. For instance on the Lutron Maestro there is a little slide switch under the paddle which has to be all the way left to make sure the silicon controlled rectifier is off.

 

[mtrycrafts]

... Could my receiver be causing the trouble? The reason I say this is when I turn it on it takes anywhere from 10 to 15 seconds until I hear a click and thats when the audio or buzz will start playing through my speakers. All the lights and screen come on as soon as I turn it on but nothing comes out of the speakers until the click. I think its 4 or 5 years old. Its a Sony STR-DE485

It could be a problem but not because of that time delay of 10-15 sec, that is an amp timer so the speakers don't get a signal for that duration while other components may be being turned on and the receiver is ready too.
By the way, do you live near an airport or military base with radar that you know of? At times they certainly can induce RF.

 

[TLS Guy]

Equipment varies greatly in susceptibility to RF interference. There is a lot the designer can do to make RF interference less likely. The thought about the transmitter is a good one.

Many many years ago I had digs at Dulwich in sight of the BBC Crystal Palace TV transmitter. It was in the tube era, and the high gain first stage EF 86 tubes picked up the audio of BBC 1 perfectly. That was when I devised the RF chokes for the speaker leads. They worked perfectly.

Can you test you receiver at a location some miles away from your residence.

The other thing you could do is connect the receiver outputs to headphones, or a small speaker on a short lead. That will tell you if it is RF getting picked up by the speaker leads.

 

[Haoleb]

I just bought a APC H15 and I'm still getting interference through my speakers. I do have florescent lightning near by, is that the problem? Also I ran my cable through it and I still have a bad picture it kinda of looks pixeley and it's not the tv.

When exactly did you start noticing the problem to begin with? Sometimes a buzz in audio equipment is indicative of bad capacitors in the power supply. Your reciever is not quite at the age where I would start to suspect that type of problem though.

 

[TLS Guy]

What ever you changed last is going to be the key to the problem. What cable did you run through a fluorescent light? I don't know how you even did that, but it was a bad plan. You have run a cable right in to a source of RF.

 

[Seth=L]

Flourescent lights can introduce noise in AC lines, but if it is off it shoudn't do anything to interfer.

 

[grizzlyman]

No I don't live near any airports or military bases. I had the problem for at least four or five months. I could of had it before but never noticed it. I also didn't run any cables through fluorescent lights. Thank you guys for all the things you're given me to try. I'm only 19 and pretty new into home theater but I want to learn as much as I can about them. I have a speaker for my bass and I hooked it up to my receiver and I was still getting the noise, what could this mean?

 

[TLS Guy]

No I don't live near any airports or military bases. I had the problem for at least four or five months. I could of had it before but never noticed it. I also didn't run any cables through fluorescent lights. Thank you guys for all the things you're given me to try. I'm only 19 and pretty new into home theater but I want to learn as much as I can about them. I have a speaker for my bass and I hooked it up to my receiver and I was still getting the noise, what could this mean?

Good luck. You actually did very well. You had done all the first things, first which made things interesting. RF interference is tough. I had a recurrence yesterday of a little SCR noise from light dimmers RF interference on the center channel. It turned out to oxidation on one RCA connector and it was a gold plated one!

 

[mtrycrafts]

... I have a speaker for my bass and I hooked it up to my receiver and I was still getting the noise, what could this mean?

Yep, noise is not easy to trace where it is coming from or the best method to eliminate it unless you know exactly what you have and even then it can be troubling.

Now this bass, is that a powered sub? Was your system making the noise even before you connected this bass to the system? Was this totally removed and disconnected from the system and still the noise?
It will take some detective work to find the source.

Neighbors close or nearby have a Ham antenna?

 

[grizzlyman]

I'm just going to buy a new receiver in a few months when I get some extra money. I think I'm going to get a Denon AVR-2308CI http://www.usa.denon.com/ProductDetails/3631.asp or http://www.onkyousa.com/model.cfm?m=TX-SR605&class=Receiver&p=fIf I still want to put them RF chokes on would they reduce the sound quality any? Also about my cable what should I do about that I have new coaxial ran from the splitter to my box. The two other televisions in the house have really good pictures. Would one of them cable amplifier help any or could it be the cable box I have a digital cable box with HD channels. I used a DVI to HDMI cable to my TV. Sorry about asking so many questions but no one else I know, knows anything about this stuff I know more than them so you guys are all I got.