Hum through speakers (TV and Stereo)

P

PCguy

Audiophyte
Good morning all,

So I have been looking through forums and searching for an answer to my problem. I am getting a hum (I guess the 60 mhz one everyone speaks about) through my stereo and TV speakers. I have read forums and read about ground loops etc, but did not see what I need to do to fix it. I have isolated it down to figuring out it only happens when lights or computer are turned on in the adjacent room, and the ceiling fan in the same room as the tv/speakers. I read somewhere that it could be caused by the lights being on the same circuit or something. How can I fix this?

Set-up:

Wall cable to Cable box (via coaxial cable)
Cable box to VCR (via coaxial cables)
VCR to DVD recorder (via A/V cables)
DVD recorder to TV (via s-video cable and Audio cables)
TV to stereo system (via Audio cables)

I replaced all the connection cables with thicker higher quality cables.
I placed a radio shack DC blocker connection from wall to cable box (cheap 4 dollar one)
All equipment is pugged into a surge protector strip (decent one)

I thought it may be the factory standard wires from the stereo to the stereo speakers being low quaility (you know the small black and red ones) and maybe not shielded (since the speakers are mount on the wall behind the TV and drape down that wall), but the internal TV speakers also give off the hum. It seems like it is affecting both sets of speakers. Without some of the lights on it is gone, once different lights in the house are turned on the hum increases.

How can I get rid of this?

Thanks, from what I have been reading looks like a lot of knowledgeable people in here. I have confidence you guys can help me out!

~PCguy
 
H

highfigh

Seriously, I have no life.
Unplug the cable from the cable box. If the hum goes away (and this is very likely), you can either put an isolation adapter on the cable feed or have the $#%@ cable company ground their feed and fix it for you. If it remains, look at what equipmnet is in pne place and what is farther from the majority of it. If you're taking an audio feed from the TV so you can watch off-air programming, unplug that and see if it stops humming. If it does, you can either put a new electrical feed to teh TV or get an isolation transformer from Radio Shack (it's cheap one, but it works) or another brand like Jensen.

It's still possible that the subwoofer is teh cause but let's start with the basic and more common causes.
 
Joeteck

Joeteck

Audioholic
Good morning all,

So I have been looking through forums and searching for an answer to my problem. I am getting a hum (I guess the 60 mhz one everyone speaks about) through my stereo and TV speakers. I have read forums and read about ground loops etc, but did not see what I need to do to fix it. I have isolated it down to figuring out it only happens when lights or computer are turned on in the adjacent room, and the ceiling fan in the same room as the tv/speakers. I read somewhere that it could be caused by the lights being on the same circuit or something. How can I fix this?

Set-up:

Wall cable to Cable box (via coaxial cable)
Cable box to VCR (via coaxial cables)
VCR to DVD recorder (via A/V cables)
DVD recorder to TV (via s-video cable and Audio cables)
TV to stereo system (via Audio cables)

I replaced all the connection cables with thicker higher quality cables.
I placed a radio shack DC blocker connection from wall to cable box (cheap 4 dollar one)
All equipment is pugged into a surge protector strip (decent one)

I thought it may be the factory standard wires from the stereo to the stereo speakers being low quaility (you know the small black and red ones) and maybe not shielded (since the speakers are mount on the wall behind the TV and drape down that wall), but the internal TV speakers also give off the hum. It seems like it is affecting both sets of speakers. Without some of the lights on it is gone, once different lights in the house are turned on the hum increases.

How can I get rid of this?

Thanks, from what I have been reading looks like a lot of knowledgeable people in here. I have confidence you guys can help me out!

~PCguy
Take a wire and connect it to the back of the receiver (Some have a grounding screw) and then down to the center screw at the outlet. If it goes away you're golden. Also you're AC outlet could be wired wrong. Neutral and hot swapped...
 
sawzalot

sawzalot

Audioholic Samurai
Take a wire and connect it to the back of the receiver (Some have a grounding screw) and then down to the center screw at the outlet. If it goes away you're golden. Also you're AC outlet could be wired wrong. Neutral and hot swapped...
While the mix up with wires is a possibility please dont check them without turning off the breaker and use a tester/meter to be sure the circuit is de-energized.Safety is the most important part of any electrical endeavor.
 
Joeteck

Joeteck

Audioholic
While the mix up with wires is a possibility please dont check them without turning off the breaker and use a tester/meter to be sure the circuit is de-energized.Safety is the most important part of any electrical endeavor.
But he'll need it turned on to use this type of tester... :D
 
P

PCguy

Audiophyte
will check

Thanks guys, will try out the things you mentioned and post tomorrow. I do have some type of cheapo coaxial DC blocker I bought from Fry's electronics, was about 3 bucks. It connected from wall coaxial between cable box, looks similar to the coaxial isolation transformer (basically a tube with female and male coaxial connectors), but I have a feeling it isn't the right piece as I saw the Jensen one was about 50 bucks.

Question, I understand the ground loop isolator from TV audio output to the stereo system input aux connector, but if I put one on (Incidentally, I bought one from radio shack but did not apply it since the hum was also coming from the internal TV speakers) and this stops the hum from the stereo, what about the hum from the internal TV speakers? The hum comes from both the TV speakers and the stereo speakers which leads me to believe it may be something else. Should I go ahead and see if I insert the new ground loop isolator audio line from TV to stereo stops the stereo speakers humming anyway?

Another note, by grounding the stereo to the outlet, would that effect the hum from the internal TV speakers also? I think the stereo power plug us only a two-pronger with no third ground prong.
 
sawzalot

sawzalot

Audioholic Samurai
But he'll need it turned on to use this type of tester... :D
I just tried my meter on my own bedroom circuit to test your theory and it reads 119v ac with breaker on now breaker off .002v ac I'd say that the circuit is off.So what did I say wrong in the first post ?
 
Joeteck

Joeteck

Audioholic
I just tried my meter on my own bedroom circuit to test your theory and it reads 119v ac with breaker on now breaker off .002v ac I'd say that the circuit is off.So what did I say wrong in the first post ?

measuring the voltage is not the issue... its how its connected inside the outlet, which is what that type does... and may be causing his AC hum..
 
sawzalot

sawzalot

Audioholic Samurai
measuring the voltage is not the issue... its how its connected inside the outlet, which is what that type does... and may be causing his AC hum..
you obviously just didnt comprehend my post too well.I never told him to measure any voltage whatsoever,I simply said in a very straightforward way,this,if you are gonna check the wiring issue-stop-go turn off the breaker-stop- then come back to the outlet-stop-take the leads from the meter and place into the outlet-stop-read meter to be sure there is no voltage present-stop -if there is a zero reading then you know you turned off the right breaker-stop- now proceed to take off the plate cover and remove the receptacle check for proper wiring-stop.

Just a tip to be safe not a debate with you for the proper usage of a meter.

but I seriously dont mind either way, ;) .
 
Joeteck

Joeteck

Audioholic
you obviously just didnt comprehend my post too well.I never told him to measure any voltage whatsoever,I simply said in a very straightforward way,this,if you are gonna check the wiring issue-stop-go turn off the breaker-stop- then come back to the outlet-stop-take the leads from the meter and place into the outlet-stop-read meter to be sure there is no voltage present-stop -if there is a zero reading then you know you turned off the right breaker-stop- now proceed to take off the plate cover and remove the receptacle check for proper wiring-stop.

Just a tip to be safe not a debate with you for the proper usage of a meter.

but I seriously dont mind either way, ;) .
The tester I recommended is used before taking the outlet out of the wall. If its wired wrong,it will tell you and if its wired correctly it will tell you that too. If its wired wrong, then you'll need to fix it and you should turn off the outlet before working with it, but I sometimes don't because its kinda fun to do it live. ;)
 
walter duque

walter duque

Audioholic Samurai
Unplug the cable box overnite (or an hour or two) and see what happens the next day. I have to do that to my box about ever 3-4 months. I was told the capacitors are overcharged, what ever it is it works for me. Or just unplug your whole system for a couple of hours. Not shut off UNPLUG. Try it, nothing to loose.
 
Joeteck

Joeteck

Audioholic
Unplug the cable box overnite (or an hour or two) and see what happens the next day. I have to do that to my box about ever 3-4 months. I was told the capacitors are overcharged, what ever it is it works for me. Or just unplug your whole system for a couple of hours. Not shut off UNPLUG. Try it, nothing to loose.
or hes having the same issue as the other user...:D
 
TLS Guy

TLS Guy

Audioholic Jedi
Good morning all,

So I have been looking through forums and searching for an answer to my problem. I am getting a hum (I guess the 60 mhz one everyone speaks about) through my stereo and TV speakers. I have read forums and read about ground loops etc, but did not see what I need to do to fix it. I have isolated it down to figuring out it only happens when lights or computer are turned on in the adjacent room, and the ceiling fan in the same room as the tv/speakers. I read somewhere that it could be caused by the lights being on the same circuit or something. How can I fix this?

Set-up:

Wall cable to Cable box (via coaxial cable)
Cable box to VCR (via coaxial cables)
VCR to DVD recorder (via A/V cables)
DVD recorder to TV (via s-video cable and Audio cables)
TV to stereo system (via Audio cables)

I replaced all the connection cables with thicker higher quality cables.
I placed a radio shack DC blocker connection from wall to cable box (cheap 4 dollar one)
All equipment is pugged into a surge protector strip (decent one)

I thought it may be the factory standard wires from the stereo to the stereo speakers being low quaility (you know the small black and red ones) and maybe not shielded (since the speakers are mount on the wall behind the TV and drape down that wall), but the internal TV speakers also give off the hum. It seems like it is affecting both sets of speakers. Without some of the lights on it is gone, once different lights in the house are turned on the hum increases.

How can I get rid of this?

Thanks, from what I have been reading looks like a lot of knowledgeable people in here. I have confidence you guys can help me out!

~PCguy
Are the lights and fan you mention driven by dimmers? I have a feeling that since your hum only occurs with the use of the mentioned lights and fan, that your problem is not a ground loop but induced SCR dimmer noise.
 
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