How Do I Eliminate AC Noise Through Sub Amp? - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 
Thread Tools
post #1 of 14 Old 08-10-2009, 06:54 PM - Thread Starter
Member
 
zhillsguy's Avatar
 
Join Date: Aug 2009
Posts: 183
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 19
Ok....I am at my wit's end. Here is my situation:

I hear loud pops with every electrical event in my house through my subwoofer amp (Behringer EP2500). My setup:
Various audio components>Onkyo AVR>ED eQ.2>Samson S-Convert>EP2500
I have everything running through a APC UPS.

I tried grounding chassis together (very difficult if the manufacturers don't give you a convenient terminal), tried a Monster surge protector with "Clean Power Stage 2"; I just tried an APC H15 with everything running through it....both before and after the UPS. It seems like a nice unit, I thought it would be the end-all fix. It was cruising at around 2 amps with everything on. Still get pops, they don't even seem reduced to me, especially switching the ceiling fan speeds, even when shutting the door/starting the microwave.

As a couple of side notes, I live in a high/dry area, but my home is only about 13 years old and am confident in the wiring. When connecting my home stuff to the "pro" EP2500, the inherent chassis ground had to be eliminated in the signal chain interconnects, otherwise the hum was unbearable (only using pins 2-3 of the XLR, that caused me enough consternation as it is).

I am familiar with grounding installations through my job. Will additional grounding of the main service help, to give the noise/spikes a place to dissipate (with a device)?

Any/all suggestions are welcome....thank you.
zhillsguy is offline  
Sponsored Links
Advertisement
 
post #2 of 14 Old 08-10-2009, 07:15 PM
AVS Forum Special Member
 
michael hurd's Avatar
 
Join Date: Nov 2007
Posts: 3,425
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 639 Post(s)
Liked: 691
Do you have cable tv / cable internet etc? Many times, the seperate grounding point at entry will cause noise issues. Try temporarily disconnection the cable tv coax to your receiver and see if that goes away. ( if you have it )

Ask your doctor if DIY is right for you. Side effects of DIY may include anxiety, elevated blood pressure, lightheadedness, rapid heartbeat, skeletal muscle flaccidity, euphoria, psychological dependence, insomnia, confusion, blurred vision, impulsivity, uncontrolled or repeated movements.
michael hurd is offline  
post #3 of 14 Old 08-10-2009, 07:16 PM
AVS Forum Special Member
 
brandonnash's Avatar
 
Join Date: Jul 2003
Location: murfreesboro, tn
Posts: 3,937
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 34
What kind of cables are you using? I had loud hum from all my speakers till I grounded the xlr cable to a negative on a speaker terminal on my receiver. After that problem was fixed.
brandonnash is offline  
Sponsored Links
Advertisement
 
post #4 of 14 Old 08-10-2009, 07:32 PM - Thread Starter
Member
 
zhillsguy's Avatar
 
Join Date: Aug 2009
Posts: 183
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 19
Thanks for the responses......

Quote:
Originally Posted by michael hurd View Post

Do you have cable tv / cable internet etc? Many times, the seperate grounding point at entry will cause noise issues. Try temporarily disconnection the cable tv coax to your receiver and see if that goes away. ( if you have it )

I only have satellite, without the main incoming coax grounded. I am using my tv as a monitor with an S-video cable connect only.

Quote:
Originally Posted by brandonnash View Post

What kind of cables are you using? I had loud hum from all my speakers till I grounded the xlr cable to a negative on a speaker terminal on my receiver. After that problem was fixed.

Brandon, do you mean the shield of the xlr, or the cold? Right now I only have rca sub out of the AVR to the eQ.2, then to the Samson, then xlr out to the EP with the shield (pin 1) disconnected on one end. I am not getting hum, only pops with electrical events. However, this is intriguing and maybe the pops could be reduced if caused by a potential difference between devices. I wouldn't want to try this unless absolutely certain it is safe for the equipment.
zhillsguy is offline  
post #5 of 14 Old 08-11-2009, 06:32 PM
Advanced Member
 
Jerm357's Avatar
 
Join Date: Nov 2005
Location: Detroit
Posts: 776
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I hate to say it, but have you tried a cheater plug on the EP2500?


Edit... I thought this was for a hum not pops caused by other equipment. I know when I used to send a very strong signal with my ART clean box to my EP1500 I used to get pops all the time even when stoping and skipping chapters with my DVD player. I came to find out I did not need the extra signal booster in the chain. Are you realy sure you do? I run an Onkyo 705 to an EP1500 with no need for a signal booster. I have even ran my older Onkyo 600 receiver without one too.

Try taking out the Samson S-Convert box and just set the level with the sub trim and the amp gains and see if it goes away.
Jerm357 is offline  
post #6 of 14 Old 08-11-2009, 06:39 PM
AVS Forum Special Member
 
TCARCIO's Avatar
 
Join Date: Nov 2005
Location: Massachussetts
Posts: 1,130
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked: 96
The OP said he is getting pops and that is not a humming problem. Did you try a different circuit?
TCARCIO is offline  
post #7 of 14 Old 08-11-2009, 07:34 PM
AVS Forum Special Member
 
Speedskater's Avatar
 
Join Date: Mar 2004
Location: Cleveland, Ohio
Posts: 2,149
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 56 Post(s)
Liked: 36
This is all way to complicated. Lets start simple. Disconnect everything. Plug the EP2500 into the wall AC power ( no filters, no UPS and no surge protector) hook-up the sub. Use a battery powered CD player (or similar) play a tune that is mostly bass. If it's quite, hook-up the receiver (to the same AC power outlet) run the CD player through the receiver. Continue on one unit at a time until the noise resumes. Then troubleshoot the last unit and whatever it's connected.

Often noises like this are caused by neutral problems in the AC wiring.

Kevin
Speedskater is offline  
post #8 of 14 Old 08-11-2009, 11:08 PM
Member
 
hawkman2's Avatar
 
Join Date: Apr 2004
Location: Zephyrhills, FL
Posts: 50
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks to all......

Quote:
Originally Posted by Jerm357 View Post

I hate to say it, but have you tried a cheater plug on the EP2500?


Edit... I thought this was for a hum not pops caused by other equipment. I know when I used to send a very strong signal with my ART clean box to my EP1500 I used to get pops all the time even when stoping and skipping chapters with my DVD player. I came to find out I did not need the extra signal booster in the chain. Are you realy sure you do? I run an Onkyo 705 to an EP1500 with no need for a signal booster. I have even ran my older Onkyo 600 receiver without one too.

Try taking out the Samson S-Convert box and just set the level with the sub trim and the amp gains and see if it goes away.

This is for pops, not hum. My Onkyo is an older TX SR-601.....I was running it without the Samson (w/eQ.2) for a while, had to run it at +10db.....now with it I run the Samson at center detent, with 0db on the AVR. Gains on the eQ and EP are at max (always have been). It is slightly louder than before, seems about right. So I CAN run it without the booster, but prefer it with. It should also be noted that even Alex from ED posted here recently that the eQ.2 should not be used with an EP (or other "pro" equipment) without a line booster, in this thread:https://www.avsforum.com/avs-vb/showthread.php?t=1165303. I remember seeing the eQ test results from an older post, distortion increased and response suffered for anything beyond 2.5V output (don't wanna get into that whole thing here...gain/voltage/impedances, etc.).

Quote:
Originally Posted by TCARCIO View Post

The OP said he is getting pops and that is not a humming problem. Did you try a different circuit?

Will try additional troubleshooting this weekend. Tried some other stuff tonight, bonded the AVR chassis (via spare speaker (-) terminal and the rear antenna coax connector) to the xlr pin 1 of the EP...seemed to help a little. Eliminated a potentially defective RCA cable (old Monster) in the chain as well. Checked with a VOM to make sure all devices had continuity on all audio commons, they did. Got tired.

Quote:
Originally Posted by Speedskater View Post

This is all way to complicated. Lets start simple. Disconnect everything. Plug the EP2500 into the wall AC power ( no filters, no UPS and no surge protector) hook-up the sub. Use a battery powered CD player (or similar) play a tune that is mostly bass. If it's quite, hook-up the receiver (to the same AC power outlet) run the CD player through the receiver. Continue on one unit at a time until the noise resumes. Then troubleshoot the last unit and whatever it's connected.

Often noises like this are caused by neutral problems in the AC wiring.

See response above. Will troubleshoot further and post results. Again, thanks to all.
hawkman2 is offline  
post #9 of 14 Old 08-12-2009, 06:55 AM
AVS Forum Special Member
 
whoaru99's Avatar
 
Join Date: Dec 2004
Posts: 6,946
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 71
Quote:
Originally Posted by hawkman2 View Post

It should also be noted that even Alex from ED posted here recently that the eQ.2 should not be used with an EP (or other "pro" equipment) without a line booster, in this thread:https://www.avsforum.com/avs-vb/showthread.php?t=1165303. I remember seeing the eQ test results from an older post, distortion increased and response suffered for anything beyond 2.5V output (don't wanna get into that whole thing here...gain/voltage/impedances, etc.).

Sorry...without getting too hairy in the details, doesn't make sense. The EPs require only about 1.25V to drive full output unless their specs are completely bogus.

But, anyway, that you are satisfied with what ever is of most importance.

Just because there is a knob doesn't mean you should turn it.
whoaru99 is offline  
post #10 of 14 Old 08-12-2009, 06:58 AM
AVS Forum Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,476
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 52
Quote:
Originally Posted by whoaru99 View Post

Sorry...without getting too hairy in the details, doesn't make sense. The EPs require only about 1.25V to drive full output unless their specs are completely bogus.

But, anyway, that you are satisfied with what ever is of most importance.

You would think that you would move on from this POV

You still actually think everyone using line boosters (like me) just have their systems setup wrong.

I posted very detailed numbers once pointing on the huge differences in output but you still ignore it all.

Quote:


It should also be noted that even Alex from ED posted here recently that the eQ.2 should not be used with an EP (or other "pro" equipment) without a line booster, in this thread:https://www.avsforum.com/avs-vb/showthread.php?t=1165303. I remember seeing the eQ test results from an older post, distortion increased and response suffered for anything beyond 2.5V output (don't wanna get into that whole thing here...gain/voltage/impedances, etc.).

That is true, I have the eQ.2 and the measurements did show increased distortion when pushed. I have removed it recently.

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #11 of 14 Old 08-12-2009, 07:11 AM
AVS Forum Special Member
 
whoaru99's Avatar
 
Join Date: Dec 2004
Posts: 6,946
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 71
Quote:
Originally Posted by penngray View Post

You would think that you would move on from this POV

You still actually think everyone using line boosters (like me) just have their systems setup wrong.

I posted very detailed numbers once pointing on the huge differences in output but you still ignore it all.

Why would I move on from a POV that is correct?

Never said he was wrong. I merely said what was posted doesn't make sense.

The EP2500 requires 1.2-something volts to drive full output. That is a fact (unless Behringer spec is wrong).

If the eQ.2 can drive 2.5V out before it becomes a problem, then there should be no concern using it before the EP.

2.5V of clean output is twice what the EP requires to get full output. What is so hard to understand about that?

Send me a link to these detailed measurement by PM. We've already distracted the thread enough.

Just because there is a knob doesn't mean you should turn it.
whoaru99 is offline  
post #12 of 14 Old 08-12-2009, 07:15 AM
AVS Forum Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,476
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 52
Quote:
Originally Posted by whoaru99 View Post

Why would I move on from a POV that is correct?

Never said he was wrong. I merely said what was posted doesn't make sense.

The EP2500 requires 1.2-something volts to drive full output. That is a fact (unless Behringer spec is wrong).

If the eQ.2 can drive 2.5V out before it becomes a problem, then there should be no concern using it before the EP.

2.5V of clean output is twice what the EP requires to get full output. What is so hard to understand about that?

Send me a link to these detailed measurement by PM. We've already distracted the thread enough.


Its a RCA to XLR thing, it always has been. We had a thread on this (many actually) so its a dead horse to me, I know what works and what doesnt.

You are correct though we do not need to distracted the thread on this topic.

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #13 of 14 Old 08-12-2009, 07:31 AM
AVS Forum Special Member
 
whoaru99's Avatar
 
Join Date: Dec 2004
Posts: 6,946
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 71
Quote:
Originally Posted by penngray View Post

Its a RCA to XLR thing, it always has been.

Not really, but whatever.

Quote:


I know what works and what doesnt.

But do you know why it works or doesn't and how to figure out if the next change will work or not, before you have to try ten different things to make it work?

Just because there is a knob doesn't mean you should turn it.
whoaru99 is offline  
post #14 of 14 Old 08-12-2009, 07:32 AM
AVS Forum Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,476
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 52
Quote:
Originally Posted by whoaru99 View Post

Not really, but whatever.

right....whatever

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs

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