Loud intermittent speaker buzz


New member
Username: Breckrider

Memphis, TN USA

Post Number: 1
Registered: Feb-10
I'm trying to help my parents with their problem. They are getting intermittent buzzing that my mother describes as a bunch of loud angry bees. It's not a hum and it doesn't happen all the time. There is a plasma tv, tivo, cable box and blueray player that goes through this receiver. The tivo has a wireless antenna connected to it. I've checked the speaker connects and they seem to be tight and solid. I don't know where else to start troubleshooting.

Gold Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 1051
Registered: Feb-08
Greetings Virginia,

One potential cause is some sort of motorized device other than the audio/video components perhaps plugged in the same electrical circuit. The sound appears when the motor is running. A power conditioning/surge protective type power strip should help if that is the cause.

Other causes could be bad cable connections but the best way to try and run down the problem is to ask your parents to write down everything (lights, air purifiers, heaters, etc.) that is turned on and exactly what they are watching when it happens and see if you can recreate the problem.

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 14516
Registered: May-04

If there's a task more thankless than hunting down intermittent noises it would be doing it for your parents who are dealing with new technology.

The key to any troubleshooting is consistent logic - if not this, then that - as you work through piece by piece the possible causes for noise pick up. Eliminate one possibility and move on to the next often times taking notes to make sure you don't fool yourself into thinking one thing while the opposite is true.

First, you'll need to identify just what the noise sounds like. I assume you have not personally heard the noise and you're going with your mother's description. If the noise is truly not a hum - a 60Hz noise low in frequency which would indicate grounding problems in the system - then you can eliminate many of the possible causes for such noise which would include poor cable quality and intermittent or broken connections along the signal path. None the less, it would be a good policy to replace any cheapo/freebie cables provided with any source type component with higher quality, after market cables just to insure you have the best possible connections in place before you proceed. Cables with molded plastic plug ends can look OK while having internal breaks.

While replacing those cables I would take the time to properly dress the system's cables as the rats nest of crossed cables behind most systems is an invitation to RFI (radio frequency interference). Buy a few of the cable ties sold at any office supply store and dress the audio cables into three groups, the AC power cables, the speaker cables and the interconnecting signal cables. If an interconnecting cable must cross an AC power cable, it should do so at a 90° angle. Parallel runs of differing groups should be kept as far apart as possible and a minimum of 6" is suggested in any case. Do not coil excess cables, rather you should make lazy "S" shapes with any extra cable lengths.

Certainly, with a wireless device in the system, the possibility for noise pick up is increased. If the choice can be made to temporarily revert to an infrared remote for the tivo, then this would be a possible course of action once you've eliminated other probabilties. Another remote or radio transmitter within the neighborhood could be your source for noise over the wireless system.

Buzzing noises (not 60Hz noise) will typically be associated with RFI and your next job would be to begin eliminating possible sources for such interference. Anything on the same circuit breaker with the system would be a normal first suspicion as they can be a source for either RFI or EMI (electromotive interference). If the refrigerator is on the same circuit, it can cause noises as the cooling system cycles on and off. You can identify which other devices are on the circuit by simply switching off the circuit at the service panel and doing an inventory of what isn't operating. Florescent lamps are a common cause for RFI as the ballast cycles at 60Hz. You might try plugging the system into a different circuit breaker using an extension cord to check for direct line induced interference if you fail to identify any possible sources on the same AC line.

After that things become much more difficult to track down. Remote controls for other devices can sometimes be a source of noise through a poorly shielded system.

Ask a few more questions about when the noise occurs. What source is being played at the time? Radio often picks up noises from passing cars, trucks and taxis. In some locations low flying air craft or emergency vehicles can cause intermitttent RFI. Of course, if your parents' house is situated in close proximity to a radio tower (ham radio is still the most likely suspect), then you can isolate the issue to times when the radio might be in use.

Is the noise heard on more than one source? If the noise is heard when playing either the cable TV or the Bluray player, then you can begin to search down specific components, plugging and unplugging sources temporarily to check for further intrusions. If the noise can be isolated to one source component, most probably the cable box, then you can work with a more focussed intent.

You might need to ask your mother to write down more specifics about when the noise is heard and what other devices might be a possible cause. Until you have a more precise target for locating possibilities you are firing blanks in your troubleshooting.

Not knowing which receiver your mother uses there is one final possibility which could be caused by RFI. An open RCA connector on the back of the receiver could be an inviting antenna for RFI pickup. A quick cure for that problem would be to head down to Radio Shack to buy a handful of their screw type (non-solder) RCA plugs and an equal number of 75 Ohm resistors of low wattage. Clip the leads of the resistors to length and make a connection between the screw type center post of the RCA and the ground lug of the same plug. Insert one plug into any open RCA jack on the receiver.

Lastly, ask about any changes to the system just prior to the noise first appearing. If a cable box or even a new interconnect cable was introduced to the system not long before the noise first appeared, then you have a better chance of finding the offending component. Good luck, take your time, take notes and be patient.

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