noise/interference lines in TV when there is a surge of power

Anytime my subwoofer draws a lot of power (or any large appliance in the house..ie washer\dryer), white dotted lines appear on the TV. When the subwoofer uses high power during loud scenes, the condition gets worse showing more pronounced interference lines. I read that cable grounding could be the issue. But, I disconnected my cable from the TV...so that only the DVD player is connected. But, I'm still noticing the problem. Even the TV in the back room shows the interference lines (to a lesser degree). I've connected the subwoofer and all my components to a/v surge protectors with line conditioning, but that doesn't help. Any ideas on how to fix the issue?

Thanks! PC

Reply to
beowulf19
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1/ Vibration 2/ Marginal house wiring 3/ Poltergeists
Reply to
Charles Schuler

LOL! I like #3

Reply to
Michael Kennedy

It sounds like you might have a wiring problem in your house. I would try using a ferrite core on the power input for your tv and dvd player. You might also try using your tv on a UPS if you have one. Thats what I would try, but I am definately not an EMI expert.

- Mike

Reply to
Michael Kennedy

I just tried connecting a UPS to the subwoofer and the TV....same result. :( I'm starting to think it really may be Poltergeists. lol :)

Vibration is not an issue...since I'm noticing the interference lines in back of the house, where the sub cannot be heard.

I also tried connecting the sub to various outlets throughout the house....with the same result.

Note: Then lines only appear for a brief second when the washer and dryer kicks on and not visible as the units continue to run. But, the lines are present anytime the sub produces bass. As I mentioned, the greater the power...more interference produced.

So, I suspect some type of faulty wiring in the house. So, a call to a electrician may be in order.

-PC

Michael Kennedy wrote:

Reply to
beowulf19

Even unknown is if interference is via radio waves (over the air), from cable, or via AC power lines. Will a ferrite bead do anything? Not for lower frequency noise. Meanwhile, what do you put that ferrite bead on? Ac electric? Cable? Speaker wires? Or maybe combinations? Just another example of why shotgun solutions rarely are useful or may only cure symptoms.

Your first efforts are to find what is and is not reason for problem. How is the house wired? What connects to that AC mains circuit. What is the connection relationship between things woofers and 'interfered with' appliance? For example, that other TV farther away may actually be electrically closer. You don't know until household wiring is first defined.

Meanwhile, you are entertaining myths if you think a surge protector does anything for this. Furthermore, what is this 'line conditioner'? To be effective, it is how many tens of pounds? Why? Any smaller 'conditioning' must already be part of the appliance.

Don't entertain myths. Don't change anything with intent to fix it. Currently, your only concern is to identify symptoms. Solutions come later. What does and does not change anything? How and how much? What share same branch circuit and what are not on same AC phase? Of course, we assume this is post 1960s wiring where safety grounds exist in all receptacles. Which appliances are two prong or three prong AC plugs? We must assume because important facts are not yet provided.

For example, what happens when the 'interfered' operates only from a battery backup UPS without any connection to AC mains. Just another essential fact to start estimating where interference is coming from. Note the word estimate - not 'know'.

Another useful testing tool may be:

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EMC/EMI is an art. Problems can be so complex that conferences of these industry professionals consist of mostly balding participants. Your hope for a useful reply is based in information you provide because useful answers involve that much grasp of technology.

Meanwhile, get rid of the myths. That surge protector does nothing. What is this 'line conditioner'? Where is this 'ground' that will somehow eliminate radio frequency noise? The ferrite bead goes where and does what? What appliances are (may be) missing required filters (to sell at discounted prices)?

More useful information. What creates interference to an adjacent AM radio when not tuned to any strong station? If you have that noise, now you have a tool to trace where that noise does and does not exist.

Do > Anytime my subwoofer draws a lot of power (or any large appliance in

Reply to
w_tom

snipped-for-privacy@iwon.com wrote in news:1165536155.157013.313730 @f1g2000cwa.googlegroups.com:

Try connecting the TV to the UPS and then *don't* plug the UPS into the wall---let it power the TV from its batteries. (That way, you completely detach the TV from your house wiring.)

Run the sub, the washer, everything that makes the dashed ines. So you still see the interference?

If so, it's coming through the air.

If not, it's coming through the house wiring.

Reply to
Jim Land

I dont think thats logical

It could be any of the following: rf instability in the amp, (depending on your local tv frequencies) vibration affecting wiring within the amp, or a nearby appliance, or some poor house wiring poor noise suppression on washing machine, fridge etc weak tv signal may be a contributor to the problem popular poor quality co-ax

It cant be: anything to do with power surges.

Getting an electrician in would likely get you nowhere.

NT

Reply to
meow2222

If there is a LARGE fluctuation between L1 and L2 and the Neutral Buss, at the fuse Panel, this would indicate a poorly grounded Neutral on the Power Pole, a Service Provider problem. or at the fuse panel, a Customer Problem.

There are rarely Power Surges on domestic power lines except during Thunder storms ! The so-called surges most people see are Voltage fluctuation due to un-balanced loads made worse by a bad Neutral Connection . The incoming 220 does not fluctuate, but due to the to a bad Neutral connection, the potential between L1 and Neutral and L2 and Neutral will swing badly with the load. This occurs most often with Aluminum Wiring, and the cure is to tweek the Ground Straps once in a while.

The incandescent bulbs are the "Poor man's Voltmeter". if you were sure that the two bulbs in question were on opposite legs of L1 and L2, one would brighten as the other would dim. There would only be a slight change in the total Voltage, so not really a "Power Surge" ! Just an INTERMITTANT noisy connection at the Neutral Buss.

Yukio YANO

Reply to
Yukio YANO

Well, after experimenting some more...let me try to provide some additional information.

My current setup:

36" CRT Television DVD player - SVHS output to the A/V A/V receiver SVHS output to the Television Cable plug into the TV

In this setup, there are major interference lines in the TV anytime the subwoofer bass kicks in. This is when I'm watching the DVD video playing the DVD audio. Now, if I switch the video to the cable input (while still playing the DVD audio), I do not notice any interference lines in the TV when the Subwoofer draws powers.

Next, I switch the A/V receiver to play audio from the FM tuner. I switched the video to display the DVD video. The TV interference lines still present.

I then changed the setup by taking the DVD SVHS output and going directly to the TV input (bypassing the receiver). I kept the A/V receiver audio output on the FM tuner, the interference lines where NO longer present. I then switch the a/v receiver to the DVD audio, the interference line were slightly present but only at high volume scenes.

Unplugging the cable from the TV had the same result.

In all cases, the cable video didn't seem to be affected by the subwoofer. (When I turned on a power drill or large appliance on...in that cases....a few white specs appear in the tv....but this is very slight.)

I did notice when I plugged the cable into the TV...the subwoofer makes a hum/buzz when the subwoofer's volume is turned high. Removing the cable, I can turn the subwoofer's volume to max and no hum or buzz at all. So, this may be a different problem. Maybe a ground loop issue?

During all my experiments, there were no diming of the lights in the house. The speakers play clean without any static.

Note: I did try plugging the TV and DVD player into the UPS and have it run competely off the battery. But, I'm unable to plug the A\V receiver and have it run off the battery without causing an overload condition. I still got the interference lines when playing the DVD audio thru the receiver as mentioned above.

I'm not sure how the house is wired, so I can't comment on that yet. House built in the early 80's.

Anyway, hopefully the extra information will help. I'm still unsure what I should try next to eliminate the problem. Obviously, I can route the DVD video directly to the TV to minimize the issue...but that still doesn't correct the problem.

Any help or additional suggestions will be appreciated. Thanks! PC

Reply to
beowulf19

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