Buzzing Speakers

[AndersSN]

I frequently experince a loud anoying buzzing or humming from my TV speakers. It's not there constantly but will appear and last from a few minnutes to an hour several times a day.

I have a brand new Smasung LED TV and it occurs on this just as it did on my old TV, so I am sure it is not a fault in the TV.

Could it be due to power fluxuation (my only guess), and if so what can be done?

Anders

[paulfr]

If by any chance you have any heavy equipment or motorized devices such

as washing machines, dryers, welders or anything operating with high power,

it can get in to the TV system thru the power line.

So be sure you are on a circuit that is independent of this possible interference.

Is the audio source the TV signal itself or are you using a CD/DVD player,

video tape recorder, or digital video recorder ?

Wild shot, but sometimes if the volume is turned up too high it will

cause an audio buzz.

My TV audio will buzz if the volume control for the UBC box is up very high.

This is a separate control from the TV volume control.

Some channels have weak audio and I have to jack it up.

Then if I go to another channel, it is too high and the audio will buzz until I lower the UBC box volume.

[AndersSN]

I have not thought about the washing machine, ot the UBC box volume (although I never use it to adjust the volume), I will investigate further next time I get 'buzzed'

It only ocurs when I watch TV through the UBC box, when I play DVD's the sound goes through the theater system, and the buzzing continues even if I mute the TV.

Edited February 3, 2010 by AndersSN

[Curt1591]

It's more than likely, classic ground hum. Unfortunately, with Thai grounding standards, or lack thereof, this is a bit problematic.

Do a google search on "ground hum".

[Beggar]

I have not thought about the washing machine, ot the UBC box volume (although I never use it to adjust the volume), I will investigate further next time I get 'buzzed'

It only ocurs when I watch TV through the UBC box, when I play DVD's the sound goes through the theater system, and the buzzing continues even if I mute the TV.

Often such things are caused by broken cables. So I would unplug the cables one by one when you hear the sound again to find such a problem.

[AndersSN]

I have not thought about the washing machine, ot the UBC box volume (although I never use it to adjust the volume), I will investigate further next time I get 'buzzed'

It only ocurs when I watch TV through the UBC box, when I play DVD's the sound goes through the theater system, and the buzzing continues even if I mute the TV.

Often such things are caused by broken cables. So I would unplug the cables one by one when you hear the sound again to find such a problem.

As in the power cables, A/V cables from the UBC box or ?

[Nordlys]

this might be worth a read...

http://www.psaudio.com/ps/how-to/finding-and-fixing-hum/

[AndersSN]

It's more than likely, classic ground hum. Unfortunately, with Thai grounding standards, or lack thereof, this is a bit problematic.

Do a google search on "ground hum".

I have done a bit of research on ground hum/ground loop and here is how I understand it.

Ground hum can occur if you have two or more systems working toghter but connected to different wall sockets. Or if you connect the power with a 3-prong A.C. cord.

Is this correct?

[SiangDeeMahk]

It's more than likely, classic ground hum. Unfortunately, with Thai grounding standards, or lack thereof, this is a bit problematic.

Do a google search on "ground hum".

I have done a bit of research on ground hum/ground loop and here is how I understand it.

Ground hum can occur if you have two or more systems working toghter but connected to different wall sockets. Or if you connect the power with a 3-prong A.C. cord.

Is this correct?

Not entirely. But you're definitely on the right track.

Just using a 3-prong A.C. cord doesn't have to mean you'll get a buzz. If it is {in fact} coming from a "ground loop" (which may be the case if you hear it all the time, no matter what video source is selected, including no source), then the buzz you hear is actually a flow of electrical current, from one ungrounded device (through your connecting wires) to a grounded one. The hum is the audio byproduct of electricity flowing "to ground". But as a previous poster correctly stated, with the poor design/construction/safety factors in Thai electrical wiring and low-end (read: Chinese) consumer AV equipment, it can indeed be very hard to find, much less electrically eliminate the cause of the hum.

It's the mixed bag of grounded and ungrounded gear connected together, that usually creates the perfect conditions for ground loops.

The "western" (and Pro-AV) approach to avoid these kinds of problems, is to try to ground EVERYTHING, or nothing, which eliminates a place for the current to flow to (but not without some risk; grounded electrical devices were invented for a reason, after all), and definitely to try to power everything from a single outlet (and therefore, a single grounding point). Even within one building, it's possible for there to be different electrical circuits that are grounded to different physical parts of the ground (the earth) outside, and therefore, some slight difference in those grounds may encourage a flow of current from one to the other (directly through your 30K bigscreen TV, causing buzz, and even shock sometimes, when things are REALLY wired poorly).

As for bad (audio/video) cables, simply unplugging a cable wont establish much about that cable (to do that, you need to "swap" that suspected cable, with another "known" working one, and see if things improve). And as for unplugging cables to locate a source of a ground loop, this has to be done VERY methodically, in a scientifically and logic-based eliminatory way. Basically, you unplug *everything*, and then then one by one, working back from one end of your signal chain to the other, you "eliminate" each device and connecting cable, from being the "guilty party". In complex A/V setups, that can end up being a lot more convoluted than it sound, folks.

And if you think that gets complicated with home stereos, imagine how crazy it gets with an entire stadiums' worth of sound systems & lighting rigs, and then add in the complexity of on-location live video broadcast and satellite uplink facilities, all interconnected together by electricity, audio, video, ligthing control signals, radio mics, wired intercoms, and walkie-talkies.

Oh. And yes... then; once it's all working, it rains, too. (and new buzz issues get born)

Just to cover another possible (and quite common source) of "buzz".. It is the unfortunate (but very common) practice for less-than-professional video technicians (located somewhere on the signal chain, between the camera, and your TV) to incorrectly overboost (overmodulate) the level of the video signal. Often, it's done to overcome inadequate signal distribution networks (but at a price to signal quality). The result of this too-strong video signal, can be that it actually bleeds (or leaks) out of the video spectrum and ends up contaminating the audio part of the signal. You can almost be 100% sure that's what's happening, if you hear the buzz suddenly get a LOT louder, whenever the video content contains a HUGE amount of white color (or a lot of pure white text) in it. Keep in mind, that with digital cable or satellite TV signals, this type of signal leakage cannot happen (in the digital realm), but that it's certainly possible that it got overdriven by someone BEFORE your digital TV provider acquired the signal that they're now sending digitally, to you.

Good luck with your buzz-hunting, people!

(i think it just might be Beer O'Clock now (at least SOMEWHERE in the world).. So I think I'm gonna go investigate a different kinda buzz right now.. cheers! and Happy Chinese New Year!)

[T_Dog]

Anders,

Is the noise constant or does it seem to change with the picture on the UBC channel you are watching?

The reason I ask this is that our UBC control box has a terrible audio signal-to-noise ratio. I have to have my UBC box set to full volume, and then I control the volume with the TV or home theater amp. If I turn the UBC box volume down to even 70 percent, the buzz from the box is horrible. It is simply noise from the control box circuitry escaping into the audio lines caused by a poor design.

[Daffy D]

After installing a new UBC box we started getting intermittent speaker humming.

Turned out it was the NEW cables from the UBC to the TV. The red/yellow/white one.

[trogers]

After installing a new UBC box we started getting intermittent speaker humming.

Turned out it was the NEW cables from the UBC to the TV. The red/yellow/white one.

Get some ferrite chokes around the troublesome cables:

http://www.articlesbase.com/electronics-ar...kes-613840.html

http://computer.howstuffworks.com/question352.htm

[Daffy D]

After installing a new UBC box we started getting intermittent speaker humming.

Turned out it was the NEW cables from the UBC to the TV. The red/yellow/white one.

Get some ferrite chokes around the troublesome cables:

http://www.articlesbase.com/electronics-ar...kes-613840.html

http://computer.howstuffworks.com/question352.htm

Na no need for all that

The new cables were faulty, just replaced thm with an old set and the buzzing stopped

[Scott]

Sorry to high-jack this older thread, but I have a similar, but slightly different problem. I have two televisions that are hooked to UBC. There is the main box in the bedroom and a secondary box on the downstairs TV. The secondary box is a super link, DSTV/CATV (Sl2004) Sl-1 box. I got it from UBC. It only allows the same channel on both television sets.

The sound on the super link TV goes completely crazy periodically--usually in the evening, but sometimes during the day. It makes the same sound as when there is nothing on TV and you just get that loud white noise. I recently moved and had the same problem at the previous house, there, however, it actually sounded like the I was getting a far away radio station.

I have changed the TV, but still have the same problem (as well as a constant buzz--but that I can live with). The new house has built in TV sockets, so it's not wires hanging all over the place.

The main TV has excellent sound, no problems. The super link is located right below, so I don't think it's a distance problem.

Any ideas or suggestions?

[astral]

Strange you should get the same problem in two houses.

It looks to me as though your receiver or the cable is picking up interference.

Have you tried turning off AC's and the like.

Check when the street light comes on, does that make a difference?

There are so many possible causes.

[WarpSpeed]

After installing a new UBC box we started getting intermittent speaker humming.

Turned out it was the NEW cables from the UBC to the TV. The red/yellow/white one.

Had exactly the same problem turned out to be the coax cables from the box unit to the TV, changed them and problem solved if the plug does not fit tightly and the center plug also in good contact that causes the buzzing sound, it is arching as it were across the contact..

Edited May 30, 2010 by WarpSpeed

[Scott]

Thanks. I'll check the cables. It has nothing to do with anything obvious, like AC, street lights etc. I even thought it might be something like a poorly tuned car of a neighbor, but it's not any of that. It's also not regular. Usually during the day it's OK and at night it will be a problem--but that might happen at 6:00 or 11:00 p.m. It is seldom like that when I turn it on, it happens after 15 minutes to 3 or 4 hours!

I will try and check the cables. (I already made sure that I am not using an extension cord after reading about the grounding loop stuff.

Thanks. I don't know if it will help, but at least it's a starting point.

[Jimi007]

Thanks. I'll check the cables. It has nothing to do with anything obvious, like AC, street lights etc. I even thought it might be something like a poorly tuned car of a neighbor, but it's not any of that. It's also not regular. Usually during the day it's OK and at night it will be a problem--but that might happen at 6:00 or 11:00 p.m. It is seldom like that when I turn it on, it happens after 15 minutes to 3 or 4 hours!

I will try and check the cables. (I already made sure that I am not using an extension cord after reading about the grounding loop stuff.

Thanks. I don't know if it will help, but at least it's a starting point.

It sounds like your "RCA" cables from the UBC box to the TV are most likely the cause. They are poor quality. My friend have the same problem but with the picture. UBC sent guys out three times or more, replaced the box and everything but the RCA cables. They can get warm and start to short. I went to his house wiggled the cable and the picture went out. I ran over to the local hardware shop bought a new one, installed it and never another problem. But there is always a chance of a ground loop, but it would be constant, not after its been on for a while... But I have no idea what a super link box is or how it's connected. If that all fails, call UBC. Maybe you'll get lucky and get someone that fix it.

Edited June 19, 2010 by Jimi007