Need a good electrician in NoVa - AVS Forum | Home Theater Discussions And Reviews

Forum Jump: 
 
Thread Tools
post #1 of 5 Old 06-20-2016, 08:19 PM - Thread Starter
Senior Member
 
KanosWRX's Avatar
 
Join Date: Dec 2003
Posts: 490
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 166 Post(s)
Liked: 52
Need a good electrician in NoVa

So I have been battling with humming issues, I am at the breaking point literally when I just want to give up and go back to a single AVR but before that I would like to have an electrician take a look and see if they can fix my issues. So I am looking for one that would know about AV gear and fixing these types of issues. Really need some help here I have been posting some in the "what would you do next time" thread but I think I have run out of ideas... This was my last post,

So tonight I took a look at my circuit breaker, all the circuits to the HT are on the right side, it goes from HT lights and wall sockets to another 15 amp, then to the left 20 amp socket in the media closet, then below that the right socket. So the HT lights and wall sockets should be in phase with the left media closet socket. So I tried plugging in all my equipment to that socket and plugging in the subs back into the wall sockets. The hum was still there, then I tried all on the right socket and the hum was there . So I guess it's not a phase issue. I tried a isolator on my RCA cable, all it seemed to do is reduce the volume and as I turned it back up to a normal level the hum was still there. The only fix is to actually plug the Subs into either of the 20amp circuits in the media closet. And to throw another wrench into this, in my moving of things around now I am back to getting a hum in all my speakers when the hdmi cable is plugged in... I am out of ideas, any other thoughts? The only thing I can think of now is figure out how to put the wall sockets on the 20 amp circuit, don't even know if that's possible without tearing up walls. And the only way to fix the hdmi hum is a ground loop lifter . This just sucks.
KanosWRX is offline  
Sponsored Links
Advertisement
 
post #2 of 5 Old 06-20-2016, 10:07 PM
HOME THEATER CONTRACTOR
 
BIGmouthinDC's Avatar
 
Join Date: Jan 2003
Location: Northern VA
Posts: 27,165
Mentioned: 175 Post(s)
Tagged: 4 Thread(s)
Quoted: 3014 Post(s)
Liked: 2536
the same phase of electrical in the circuit box is not on one side, it alternates from side to side. Every other single height breaker is on the same leg. Two 1/2 height breakers next to each other are on the same leg.

Have you disconnected any satellite or cable connections they can be a source of hum, And their grounds at the point of entry into the house may not be bonded to the house ground. It is best practice but often skipped due to the expense of the wire and time to complete

Lastly you may have used coax cables for your subs with copper plated steel cores rather than quad shield with solid copper cores.


Last edited by BIGmouthinDC; 06-20-2016 at 10:15 PM.
BIGmouthinDC is offline  
post #3 of 5 Old 06-21-2016, 06:22 AM - Thread Starter
Senior Member
 
KanosWRX's Avatar
 
Join Date: Dec 2003
Posts: 490
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 166 Post(s)
Liked: 52
Thanks Big for the info, still a little confused though. Here is an actual picture of my breaker box, are you able to tell what is what? Not sure why the picture is sideways.. isn't that way on my computer. But the one labeled HT Lights is actually for the lights and sockets in the HT, so the subs are plugged into this. The one below it labeled basement sockets actually doesn't go to anything in the HT. Then the two below it are as they are labeled for the media closet.

Also, no satellite or cable is coming into the media closet. I have fios that runs into my HD Homerun's in my network closet, then from there all TV goes over ethernet to my HTPC's in the house. I tried disconnecting the ethernet just to make sure but that had no effect.

This is my Subwoofer cable (I also have a monoprice 50ft cable but it has the same issue), https://www.amazon.com/Mediabridge-U...rca+cable+50ft I am beginning to think its the cable causing the problem more and more now. I have another subwoofer same make and model, with the same make cable, but only about 15 ft as it runs to the back of the room near the media cabinet and didn't need to be as long. That sub doesn't hum like the sub at the far front of my room. I noticed it says copper clad, so it does have a steel core But with all that said, why would the subwoofer hum go away when plugged into the 20amp circuit as my other gear?

So here is where I am at as of this morning.

All AV components plugged into left socket at media cabinet. Projector is ground lifted for now as the HDMI out causes a hum in all speakers (can reduce it with ground wires connecting processor and amps.. still working on this one though but for now using a temporary fix). Both subs are plugged into the wall sockets (15amp circuit labeled HT Lights). Right now with this setup I seem to only get a hum out of the front subwoofer, it happens as soon as I plug in the RCA cable to the sub.

If it is indeed the long 50ft run of RCA cable any recommendations on a specific cable to try instead? Also what if I got a wireless rca adapter for this sub, is that even worth considering? I found this one which looks really good, even has a ground attachment point.. any thoughts on that?

http://www.crutchfield.com/p_703BLAB...52-5-feet.html
Attached Thumbnails
Click image for larger version

Name:	20160620_210206541_iOS.jpg
Views:	59
Size:	199.4 KB
ID:	1508265  

Last edited by KanosWRX; 06-21-2016 at 06:45 AM.
KanosWRX is offline  
post #4 of 5 Old 06-21-2016, 08:03 AM
HOME THEATER CONTRACTOR
 
BIGmouthinDC's Avatar
 
Join Date: Jan 2003
Location: Northern VA
Posts: 27,165
Mentioned: 175 Post(s)
Tagged: 4 Thread(s)
Quoted: 3014 Post(s)
Liked: 2536
Temporarily move your subwoofer so that you can connect it with a much shorter cable, see if the hum goes away, if yes you could try that cable. I have no hands on experience with that design.
BIGmouthinDC is offline  
post #5 of 5 Old 06-23-2016, 09:03 AM - Thread Starter
Senior Member
 
KanosWRX's Avatar
 
Join Date: Dec 2003
Posts: 490
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 166 Post(s)
Liked: 52
So I was talking with Rythmik who makes my Subs, they had suggested that because of the long 50ft run the ground was loosing it effectiveness. They said to try a cheater plug to test and that in deed fixed the hum from the subwoofer. I do have the higher quality RCA cable coming still though and will run that, hopefully that fixes it so I don't need to use a cheater plug. But at least this has resolved the Sub Hum issue. Now just to figure out what causes the hum in all my speakers when the HDMI out cable is plugged in.. that one is fixed with a cheater plug in the projector right now. I also have XLR/RCA converters for my remaining RCA cables. This way at least everything will be plugged into the XLR outs on the 7700 mkii. I found that helped with a very loud hum when the rear heights were plugged into the RCA outputs. Funny the front heights didn't have the same problem. Just crazy how much time you can spend tracking down this ground loop issues, probably spent at least 8-10 hours playing around with things so far.
KanosWRX is offline  
Sponsored Links
Advertisement
 
Reply Dedicated Theater Design & Construction

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off