Humming speakers

[talannar]

I have a humming coming through my speakers. I've searched through the forums for ground loop fixes and suggestions and tried a lot of them. I have tried:

1. Trying the amp in another room (actually 2)
2. disconnecting everything from the pre/pro but the amp
3. changing speaker cables
4. changing interconnects
5. checking the cable tv ground wire
6. turning off the circuit breakers through the entire house except for the one in the room, turned off everything else on the circuit, unplugged the power strip, unplugged the cable tv from the wall and connected the amp directly to the wall socket
7. checked with multiple speakers
8. tried a Jensen iso-max on the rf cable

I'm about at my wits end here. I did connect my amps (2 channel and a 5 channel) together at the chassis with a 14 gauge wire and the humming isn't as loud, but you can still here it when you stand next to the speaker and it gets amplified once the system is on and you can hear it during quiet moments in tv/movie/music.

I've added three pictures for some clarification of what I found when I went hunting the house ground. I found that two ground wires are coming out of the electrical box outside. (grounds.jpg). The blue arrow is the wire that leads into the house, the red arrow is the wire that goes into the actual ground. I tried connecting the two grounds with a spare length of 14 gauge wire but that didn't get rid of the hum

The second pic (random ground.jpg) shows a random grey sheathed wire that is coming up out the ground. It is attached to the house ground (red arrow wire from grounds.jpg), but I haven't the slightest clue why. I tried removing it, still have the hum. I tried attaching it to the ground wire that goes into the house (blue arrow wire from grounds.jpg) but I still have the hum. The green wire is the cable tv ground. In the bottom left hand corner you can see the ground (blackish wire) going into the ground.

The third pic (GW to nowhere.jpg) shows that the ground that is coming into the house (blue arrow wire from grounds.jpg) doesn't attach to anything. I didn't see anything at the back of the breaker box that looked like a ground wire.

I'm hoping that someone here has an idea that I can try next. I'll pretty much try any tip or trick to see if it works. I'd also like to know if the "ground wire to nowhere" should actually be attached to something. Thanks in advance for any assistance

 

[TLS Guy]

I have a humming coming through my speakers. I've searched through the forums for ground loop fixes and suggestions and tried a lot of them. I have tried:

1. Trying the amp in another room (actually 2)
2. disconnecting everything from the pre/pro but the amp
3. changing speaker cables
4. changing interconnects
5. checking the cable tv ground wire
6. turning off the circuit breakers through the entire house except for the one in the room, turned off everything else on the circuit, unplugged the power strip, unplugged the cable tv from the wall and connected the amp directly to the wall socket
7. checked with multiple speakers
8. tried a Jensen iso-max on the rf cable

I'm about at my wits end here. I did connect my amps (2 channel and a 5 channel) together at the chassis with a 14 gauge wire and the humming isn't as loud, but you can still here it when you stand next to the speaker and it gets amplified once the system is on and you can hear it during quiet moments in tv/movie/music.

I've added three pictures for some clarification of what I found when I went hunting the house ground. I found that two ground wires are coming out of the electrical box outside. (grounds.jpg). The blue arrow is the wire that leads into the house, the red arrow is the wire that goes into the actual ground. I tried connecting the two grounds with a spare length of 14 gauge wire but that didn't get rid of the hum

The second pic (random ground.jpg) shows a random grey sheathed wire that is coming up out the ground. It is attached to the house ground (red arrow wire from grounds.jpg), but I haven't the slightest clue why. I tried removing it, still have the hum. I tried attaching it to the ground wire that goes into the house (blue arrow wire from grounds.jpg) but I still have the hum. The green wire is the cable tv ground. In the bottom left hand corner you can see the ground (blackish wire) going into the ground.

The third pic (GW to nowhere.jpg) shows that the ground that is coming into the house (blue arrow wire from grounds.jpg) doesn't attach to anything. I didn't see anything at the back of the breaker box that looked like a ground wire.

I'm hoping that someone here has an idea that I can try next. I'll pretty much try any tip or trick to see if it works. I'd also like to know if the "ground wire to nowhere" should actually be attached to something. Thanks in advance for any assistance

What happens if you connect the power amps to your speakers with nothing connected to the power amp, and no grounds between them?

Do your power amps have grounding plugs, and what are your amps?

Does your pre/pro have a grounding plug and what is it?

Your house ground looks pretty standard, however it looks as if it might be in a dry area, and we don't know how long it is.

If your power amps hum when not connected to anything but the AC and the speakers, there is something wrong with them.

 

[talannar]

What happens if you connect the power amps to your speakers with nothing connected to the power amp, and no grounds between them?

With the 2 channel amp, no interconnects, not connected to the chassis of the 5 channel, I get the hum and its louder.

With the 5 channel amp, no interconnects, not connected to the chassis of the 2 channel, I get the hum and its louder.

Do your power amps have grounding plugs, and what are your amps?

The 2 channel is a Rotel 990BX, the 5 channel is a Rotel 1075. Both the amps have 2 prong plugs

Does your pre/pro have a grounding plug and what is it?

I have a Rotel 1068 pre/pro that also has a 2 prong plug.

Your house ground looks pretty standard, however it looks as if it might be in a dry area, and we don't know how long it is.

If your power amps hum when not connected to anything but the AC and the speakers, there is something wrong with them.

I thought that at first as well. I took my 2 channel to the A/V repair shop at work and they told me that there is nothing wrong that they can find. When they attach a speaker to it the speaker is quiet.

The only thing I haven't had a chance to try yet is taking the amp to another location and seeing if it works there.

 

[TLS Guy]

What happens if you connect the power amps to your speakers with nothing connected to the power amp, and no grounds between them?

With the 2 channel amp, no interconnects, not connected to the chassis of the 5 channel, I get the hum and its louder.

With the 5 channel amp, no interconnects, not connected to the chassis of the 2 channel, I get the hum and its louder.

Do your power amps have grounding plugs, and what are your amps?

The 2 channel is a Rotel 990BX, the 5 channel is a Rotel 1075. Both the amps have 2 prong plugs

Does your pre/pro have a grounding plug and what is it?

I have a Rotel 1068 pre/pro that also has a 2 prong plug.

Your house ground looks pretty standard, however it looks as if it might be in a dry area, and we don't know how long it is.

If your power amps hum when not connected to anything but the AC and the speakers, there is something wrong with them.

I thought that at first as well. I took my 2 channel to the A/V repair shop at work and they told me that there is nothing wrong that they can find. When they attach a speaker to it the speaker is quiet.

The only thing I haven't had a chance to try yet is taking the amp to another location and seeing if it works there.

Since everything has two prong plugs this is not a grounding issue.

Since the amps work elsewhere there is something drastically wrong with your house wiring, most likely a live neutral reversal.

If your amps do not hum in another house, don't sleep another night in your house, until it is thoroughly checked out by an electrician.

 

[highfigh]

What happens if you connect the power amps to your speakers with nothing connected to the power amp, and no grounds between them?

With the 2 channel amp, no interconnects, not connected to the chassis of the 5 channel, I get the hum and its louder.

With the 5 channel amp, no interconnects, not connected to the chassis of the 2 channel, I get the hum and its louder.

Do your power amps have grounding plugs, and what are your amps?

The 2 channel is a Rotel 990BX, the 5 channel is a Rotel 1075. Both the amps have 2 prong plugs

Does your pre/pro have a grounding plug and what is it?

I have a Rotel 1068 pre/pro that also has a 2 prong plug.

Your house ground looks pretty standard, however it looks as if it might be in a dry area, and we don't know how long it is.

If your power amps hum when not connected to anything but the AC and the speakers, there is something wrong with them.

I thought that at first as well. I took my 2 channel to the A/V repair shop at work and they told me that there is nothing wrong that they can find. When they attach a speaker to it the speaker is quiet.

The only thing I haven't had a chance to try yet is taking the amp to another location and seeing if it works there.

Go to Home Depot and buy a circuit tester- it's in the electrical section where they have hand tools by Greenlee and Gardner Bender. Get the kind with a button for testing GFI outlets. Plug it into all of your receptacles and make note of which ones have hot/neutral reversals, lifted neutral or lifted ground.

Have you, or anyone else, changed any of the outlets? Did you have any other wiring done?

Who ran that wire through the duct? They should be taken out and shot. It's great that they ran it at a right angle to the power cable but it's awfully close.

You not only need to make sure the cable feed is grounded, you also should disconnect it to make sure the feed doesn't have voltage leaking into the center or shield- this is common with older cable company equipment and causes hum & noise bars on video.

 

[Rickster71]

Here are a few examples of the receptacle tester Highfigh mentioned: http://www.mytoolstore.com/ideal/ide05-08.html

Do you have any issues with incandescent lights dimming or flickering? If the receptacle tests go well, have a qualified person check your panel connections, neutrals and grounds.

I'm not convinced that's a ground wire going into the duct; looks like copper tubing. It almost looks like a humidifier line, or maybe an AC return.
The wire or tube had to be stuck into the insulation after being wrapped, since there is no cut or seam......and then where does it go?

 

[talannar]

To TLS Guy

I'll take the amp to another location, see what happens, and report back.

To highfigh

I've unplugged the RF cable from the wall and I've tried disconnecting it at the cable box outside. Hum is still there. Now that I think about it, I haven't tried disconnecting the cable at the outside box AND disconnecting the ground wire at the same time. I can try that and get back to you.

To highfigh and Rickster71

It is a copper wire, but it doesn't go through the duct, it goes over it. The angle I took the picture does makes it look like it goes through, and I apologize for taking it at that angle. The part that I circled is the end of the wire, it is just hanging there, and is not touching the duct at all.

To all

I borrowed a circuit tester and I went around the house. There is one outlet in the master bed upstairs that shows up as an open neutral. Pulling the outlet from the wall shows a single romex wire (black/white/ground) that I traced to the light switch. The light switch controls the lights on the ceiling fan. I've attached a pic (in MS Paint, so go with me here)

So, the grey wires are the normal white wires, gold is ground, purple boxes are the wire caps. The pic shows what the wires looked like when I followed everything up to a wire box in the attic. As you can see, there was a loose white wire not attached to anything. So I thought that was my problem.

I removed the red wire on both ends from the equation and connected the white wires together in the attic box, and attached the white wires to the switch. When I do that, the analyzer shows that the outlet is properly wired, but when I turn on the light switch the analyzer lights switch to hot/ground rev, and the outlet does not work. Turning off the light switch puts the analyzer back to properly wired. I was using my wife's hair dryer as my "outlet tester" and when I turned on the hair dryer, with the light switch off, it would turn on my ceiling fan lights.

I also tried hooking the red wire from the switch to the black wires in the attic box and hooking the white wires together in the attic box, but it didn't work either.

And I tried hooking the two white wires and the red wire together in the attic box, leaving the red wire and white wires where they were at the switch, but I got the same properly wired/hot and ground rev from the first change.

Was the wiring done correctly to start with? I did do testing with all the circuit breakers off except the one in the theater area. Would incorrect wiring, even with the circuit breaker off, possible cause the hum? I could always disconnect the outlet and check the speakers out that way. Is it possible that there might be an error somewhere else along the circuit? If so, disconnecting the the outlet probably won't help.

 

[TLS Guy]

To TLS Guy

I'll take the amp to another location, see what happens, and report back.

To highfigh

I've unplugged the RF cable from the wall and I've tried disconnecting it at the cable box outside. Hum is still there. Now that I think about it, I haven't tried disconnecting the cable at the outside box AND disconnecting the ground wire at the same time. I can try that and get back to you.

To highfigh and Rickster71

It is a copper wire, but it doesn't go through the duct, it goes over it. The angle I took the picture does makes it look like it goes through, and I apologize for taking it at that angle. The part that I circled is the end of the wire, it is just hanging there, and is not touching the duct at all.

To all

I borrowed a circuit tester and I went around the house. There is one outlet in the master bed upstairs that shows up as an open neutral. Pulling the outlet from the wall shows a single romex wire (black/white/ground) that I traced to the light switch. The light switch controls the lights on the ceiling fan. I've attached a pic (in MS Paint, so go with me here)

So, the grey wires are the normal white wires, gold is ground, purple boxes are the wire caps. The pic shows what the wires looked like when I followed everything up to a wire box in the attic. As you can see, there was a loose white wire not attached to anything. So I thought that was my problem.

I removed the red wire on both ends from the equation and connected the white wires together in the attic box, and attached the white wires to the switch. When I do that, the analyzer shows that the outlet is properly wired, but when I turn on the light switch the analyzer lights switch to hot/ground rev, and the outlet does not work. Turning off the light switch puts the analyzer back to properly wired. I was using my wife's hair dryer as my "outlet tester" and when I turned on the hair dryer, with the light switch off, it would turn on my ceiling fan lights.

I also tried hooking the red wire from the switch to the black wires in the attic box and hooking the white wires together in the attic box, but it didn't work either.

And I tried hooking the two white wires and the red wire together in the attic box, leaving the red wire and white wires where they were at the switch, but I got the same properly wired/hot and ground rev from the first change.

Was the wiring done correctly to start with? I did do testing with all the circuit breakers off except the one in the theater area. Would incorrect wiring, even with the circuit breaker off, possible cause the hum? I could always disconnect the outlet and check the speakers out that way. Is it possible that there might be an error somewhere else along the circuit? If so, disconnecting the the outlet probably won't help.

Where does the power come in from the panel?

From your drawing it looks as if neither the fan or that outlet are connected to neutral.

I don't think your diagram can be correct. The switch looks to be shorting the input to the fan.

It looks a total mess. You need a meter to know which lines are the hots.

 

[Rickster71]

Either there's another feed in that receptacle (bottom left) or there is a feed coming in at the fan in it's ceiling box.
How is the fan getting power?
Is the fan's motor controlled with another switch on the wall?
I think there's something missing from your picture, or It's a homeowner wiring job.

 

[TLS Guy]

Either there's another feed in that receptacle (bottom left) or there is a feed coming in at the fan in it's ceiling box.
How is the fan getting power?
Is the fan's motor controlled with another switch on the wall?
I think there's something missing from your picture, or It's a homeowner wiring job.

I agree, that diagram is either incomplete or wrong. Either way the wiring is a mess.

The OP needs a qualified electrician. It is far do dangerous for the OP to be rearranging the wiring connections.

For two ground isolated power amps to hum with no connections except the speakers, there has to be something badly wrong, and likely dangerous to boot.

 

[talannar]

The fans look to be getting their power from the attic light. It's a simple pull chain fixture and the fans (3) are getting their power from there. I checked the connections, but everything appears to be wired the way it should be. I just don't know where the issue is.

I did get the amp over to a buddies house. They've been in the house for about a year, and it was completely rewired when they added the addition, so I felt pretty confident that everything would be wired correctly. Plugged the amp (2 channel) into the wall and attached the speaker....got a hum.

At this point I'm going to say that it is the amp. There is an audio place here that does repair, so I'm going to give them a call and see what they say. I'll keep everyone posted on what happens.

 

[TLS Guy]

The fans look to be getting their power from the attic light. It's a simple pull chain fixture and the fans (3) are getting their power from there. I checked the connections, but everything appears to be wired the way it should be. I just don't know where the issue is.

I did get the amp over to a buddies house. They've been in the house for about a year, and it was completely rewired when they added the addition, so I felt pretty confident that everything would be wired correctly. Plugged the amp (2 channel) into the wall and attached the speaker....got a hum.

At this point I'm going to say that it is the amp. There is an audio place here that does repair, so I'm going to give them a call and see what they say. I'll keep everyone posted on what happens.

It's the amp.