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Disco
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Re: How to solve speaker 'hum' due to powerline network

Mon Jun 11, 2012 2:00 am

Sorry, I didn't see your question. It's a bit late now for the clarification, but I plugged it into a different socket 5 feet away. I believe it's on a different circuit. Thanks again for all the info. The powersupply has worked a couple times, keeping my machine on uninterupted when the power has gone out due storm activity.

dave
 
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Re: How to solve speaker 'hum' due to powerline network

Fri May 31, 2013 2:11 am

Discovery of this discussion saved me a lot of time in resolving the same issue with noise in my computer speakers due to a powerline device. I have a Windows 7 machine and the same Cambridge speakers as Disco. I installed a Netgear Powerline 500 WiFi Access Point, model XWNB5201 and got sporadic soft crackling sounds coming from the computer speakers. When I unplugged the powerline device at the computer (VS what I'll call the remote powerline device) the sound stopped. When I shut the computer down the sound stopped. The computer is in my home office and the remote powerline device is in a family room in the opposite side of the house. In the office I have a DSL connection to the internet. The crackling sounds became more constant and frequent as my internet browsing activity increased. When streaming a Netflix movie the soft crackling was constant. It was irritating enough to make me search for a solution and I found this discussion. I moved the powerline device at the computer to every outlet in the office, the sound persisted. All outlets in the office are on the same circuit breaker. Finally I moved the powerline device to an outlet on another circuit and the sound was gone. I was lucky to have an outlet on a different circuit close to my office. Wanted to add my experience in hopes it may help others the way this discussion helped me.

Mike
 
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Re: How to solve speaker 'hum' due to powerline network

Wed Dec 03, 2014 5:41 pm

Also having this issue, but I'm renting an apartment and don't have the option to move the powerline device to another circuit. I was actually planning on getting the same UPS as Disco, but it seems that it did not fully resolve the issue. My problem sounds much more like msmunger's where it's not a steady hum but instead audible noise that fluctuates based on network activity. I wonder if Disco and msmunger's issues are similar but distinct. I've considered getting a UPS with "Active PFC" as that seems more likely to ensure "clean" power is getting delivered to my speakers and computer.

Perhaps it's not that the speaker power is dirty, but instead the signal delivered along the ethernet cable from the powerline adapter to the computer then into the motherboard and into 3.5mm adapter to the amp and then from amp to the speakers. I'll try unplugging the powerline adapter's ethernet cable on the comp side when I get home and see if that helps . I don't really hear the noise on the headphones plugged into the computer, but only the speakers attached to the amp attached to the comp. The amp has a separate power cable attached to the same power strip as the comp.
 
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Re: How to solve speaker 'hum' due to powerline network

Wed Dec 03, 2014 6:07 pm

I've always had some degree of noise with internal PC audio. Sometimes it's the power. Sometimes it's the receiver I have the system hooked up to. Sometimes the video card is so awesome it radiates its warm glowing warming glow right into the audio lines, and you can actually hear the noise changing when you move the mouse. The only real solution I've found is to use a digital audio connection to get the signal out of the computer box. If I plug the analog line out from my PC into my stereo I'll get noise. If I run HDMI audio to my TV (which I use as my primary display) and then run an analog line from the TV into the stereo I don't get noise.
 
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Re: How to solve speaker 'hum' due to powerline network

Thu Dec 04, 2014 8:43 am

@Errant911 - If you can't hear the noise on headphones, the amp may be picking up EMI through the cabling between the PC and the amp. Looping the audio cable several times through a ferrite ring and/or using a better cable may help.

Or it could be that your PC's line out is just noisy. You could diagnose this by temporarily switching the amp connection to the headphone jack.
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Errant911
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Re: How to solve speaker 'hum' due to powerline network

Thu Dec 04, 2014 2:42 pm

Both the speaker amp and the headphones are connected to the comp by standard 3.5mm aux jacks into the computer motherboard.The MOBO is a GIGABYTE GA-P55A-UD3 LGA Image
On the front, there is a bank of 6 different colored ports to plug the jack in all right next to each other.

The headphones and the amp are each connected to one of the jacks. I am going to turn the headphones up and see if the noise is there, just not as noticeable. If it is, then it's not likely to be the A/C power that's dirty, but instead some interference making its way into the mobo from the powerline. Btw, my amp is something like "Pyle Home PCA4 Mini 2x120 Watt Stereo Power Amplifier" (i'm not at home so I don't know the exact power rating, but it's that base model).
Image
Nothing fancy, and I've never had any issues with it until now. The noise is present whether or not any music/sound is being pushed through the speakers and is independent of the volume setting on the amp.

**Apologies for the large images. I tried to link to the product pages, but got a notification saying I can't post URLs.
 
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Re: How to solve speaker 'hum' due to powerline network

Thu Dec 04, 2014 7:28 pm

Pyle, ugh. If anything had a corner cut in that setup, it'd be that.

If the sound comes though regardless of the volume level set on the amp then it's coming in through either your input cables or your power line on the amp itself.

EDIT: Another check - if you turn down the volume on your computer, does the sound become more quiet?


For a cheap replacement (that probably puts out just as much, if not more, power) you might consider: http://www.amazon.com/Lepai-LP-2020A-Tr ... p-2020a%2B
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Re: How to solve speaker 'hum' due to powerline network

Thu Dec 04, 2014 8:55 pm

Also, the amp is likely more sensitive to low-level interference than the headphones. If the problem is induced EMI in the cabling, the low(er) impedance of the headphones (compared to the amp's line in) could be skewing things.
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Errant911
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Re: How to solve speaker 'hum' due to powerline network

Tue Dec 09, 2014 5:59 pm

@Waco Yes, the amp was purchased as a cheapo option to connect everything, and I simply never got around to replacing it.

Things I've checked that have NOT had any affect on the existence or volume of the noise
  • Unplugging ethernet cable between powerline device and computer
  • Adjusting volume on the computer from min to max
  • Adjusting physical volume knob on the crappy amp
  • Allowing everything to "warm up"

I really expected adjusting the volume knob on the amp to change the volume of the noise, but I've not heard any change. Also, regardless of the volume setting on the computer, I could not hear the noise on my headphones (Audio Technica ATH-A700X).

**Update 2014-12-12. Disabling the ethernet adapter on the only computer using the powerline device eliminates the interference. I can still browse via Wi-Fi with no interference even with the powerline system still connected. Only when I re-enable the comp's ethernet adapter and browse the net through the hardwired connection does the noise return.**
Last edited by Errant911 on Fri Dec 12, 2014 7:50 pm, edited 1 time in total.
 
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Re: How to solve speaker 'hum' due to powerline network

Tue Dec 09, 2014 7:48 pm

Sounds like the crappy amp is... well... crap. Time for a new amp.
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Errant911
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Re: How to solve speaker 'hum' due to powerline network

Fri Dec 12, 2014 7:33 pm

I think I might get this filter http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=C2
Image.
Manual says it has between 40-50 dB of attenuation for EMI/RFI noise from 150kHz - 30 MHz which is the bulk of where powerline networks transmit (source http://www.itworld.com/article/2832302/how-and-why-to-extend-your-network-with-power-line-networking.html

Here is the model of powerline device I use. It claims a frequency band of 2MHz-68MHz. I should send them an email that their "built-in RFI/EMI filters" are crap... http://www.zyxel.com/us/en/products_services/pla5215.shtml?t=p
Image

Even with the filter, I may hunt for a new amp/receiver. Time to do some shopping, but I'd like to stay in $50-75 range.

I'll update the post if something I try resolves the issue. The other night I tried disabling the ethernet adapter on the computer (so no data would be requested through the powerline system), and the interference disappeared. So... even if the powerline is connected and operating, it only causes interference when I request data through the hardwired connection (but no noise when using purely Wi-Fi).
 
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Re: How to solve speaker 'hum' due to powerline network

Fri Dec 12, 2014 9:40 pm

Errant911 wrote:
The other night I tried disabling the ethernet adapter on the computer (so no data would be requested through the powerline system), and the interference disappeared. So... even if the powerline is connected and operating, it only causes interference when I request data through the hardwired connection (but no noise when using purely Wi-Fi).

That being the case, I'm thinking it is possible your amp is picking up radiated EMI from the Ethernet cable or NIC, not from the powerline network. Filtering the power line isn't going to make any difference if that's what is going on.

You're also going to have a tough time getting a quality amp for $50-$75, so if that's your budget I think it is going to be hit-or-miss whether it's an improvement over what you have now.

Edit: Wait... a few posts back you said disconnecting the Ethernet cable had no effect. But disabling the NIC made the noise go away? Please confirm. The PC would not have been receiving data over the powerline network in either case.
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Re: How to solve speaker 'hum' due to powerline network

Tue Dec 23, 2014 9:59 pm

... aaaand I'm joining the "my amp picks up interference from powerline ethernet" club.

I'm running an old but very good Arcam Alpha 3 until I can afford a proper receiver to put there (just by running the headphones out from the TV into it). Simply put, I hear the packets just fine through the speakers, at a constant volume - regardless of whatever volume setting I have on the amp. I bet that if I heard them long enough, I could decode TCP/IP data in my head, Matrix-style.

The only thing that (so far) has helped the is plugging the amp to a cable-company-supplied surge protector (very small, two plugs only). The noise is still there, but much quieter. Too bad it can still be easily heard at night with low volumes. I bet I could easily filter this out, if I only knew how. I know electricity basics but not much beyond that. I take it just putting a ferrite choke on the power cable would do jack?
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Re: How to solve speaker 'hum' due to powerline network

Tue Dec 23, 2014 10:06 pm

morphine wrote:
I take it just putting a ferrite choke on the power cable would do jack?

That is actually worth a try. It might indeed do jack, but OTOH it might reduce the interference enough to make it tolerable. Just daisy-chaining another cheap surge protector is probably worth a try too, since the first one made a difference.
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Kougar
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Re: How to solve speaker 'hum' due to powerline network

Wed Dec 24, 2014 6:19 pm

I'm surprised, I didn't know this was a problem. I've used... four different makes and models of powerline equipment and not experienced this even with bookshelf speakers. Though all the gear was 200Mbps or less, none of the much higher rated gear they sell now. Sorry to hear you guys are having issues with it. :-?
 
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Re: How to solve speaker 'hum' due to powerline network

Sat Jan 03, 2015 12:23 am

**SOLVED** :D
So update, I finally pulled the trigger and got the power filter I reference in the above post (pictured below), and it did wonders. I've plugged the filter into the wall, then plugged the powerstrip that has the comp + speakers into the filter. Noise is totally gone and powerline still works great!

Image
 
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Re: How to solve speaker 'hum' due to powerline network

Mon Sep 28, 2015 2:29 am

This thread spans almost 4 years but should never be considered dead - it is in fact the most useful information I've found that deals with speaker buzz/hum. For that I thank every poster that's preceded me. Also, I think it worth noting that I registered on the board just to extend that thanks and to offer a little something myself...

The source of my humming woes, which I traced using logic developed by reading this thread, turned out to be my Xbox 360.
I am not certain exactly what it is that causes the interference, but with it plugged into my amp/receiver I get a constant, unchanging, and very annoying hum from all of the speakers in the system save the tweeters. It doesn't matter which input I use (I've tried all of them: 3 video, CD, tape, phono, monitor, etc), it buzzes constantly. I can drown it with volume, but any quiet moments, just aren't. The buzz doesn't fluctuate with the volume much like my predecessors'.

I haven't found a solution that still includes the Xbox with this set-up, hopefully somebody down the line will have answers. For now my rarely used console gets the silent treatment or some cumbersome ear-wear.

Thanks again to all involved that don't have to be.
 
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Re: How to solve speaker 'hum' due to powerline network

Wed Sep 30, 2015 4:54 pm

Perhaps plug the Xbox 360 to a surge protector?
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Re: How to solve speaker 'hum' due to powerline network

Wed Sep 30, 2015 4:57 pm

morphine wrote:
Perhaps plug the Xbox 360 to a surge protector?

Use an 3-prong to 2-prong cheater plug to "lift" the ground. That's usually the path hum takes.
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morphine
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Re: How to solve speaker 'hum' due to powerline network

Wed Sep 30, 2015 5:01 pm

I should perhaps also take this opportunity to say I eventually fixed my wagon by daisy-chaining two surge protectors. I'll have to see the exact arrangement though.
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chamzamzoo
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Re: How to solve speaker 'hum' due to powerline network

Tue Mar 15, 2016 4:45 am

Does anyone know what powerline filter that is Errant posted above? The link no longer works.

I have the exact problem described and have yet been unable to find a solution, this is a useful thread indeed!
 
Aether
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Re: How to solve speaker 'hum' due to powerline network

Tue Mar 15, 2016 9:05 am

"Does anyone know what powerline filter that is Errant posted above?"

I believe it was this ...

http://www.amazon.com/gp/product/B000OF4R8C
 
Mdixson
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Re: How to solve speaker 'hum' due to powerline network

Sun May 15, 2016 3:47 pm

So as others have said this post is extremely useful as an online resource.

For me the suggestion of a switch for the Ethernet has solved the problem and I would recommend others try this. Thanks for the advice all.
 
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Re: How to solve speaker 'hum' due to powerline network

Mon May 23, 2016 1:17 pm

I wish I found this thread earlier so I didn't have to go through the pain to troubleshoot my own subwoofer hum. I had violent hum from my subwoofer so loud that I thought it's gonna be destroyed, with no RCA cable connected (no audio signal) and only the power cable connected to the wall or the power strip. I was at one point guessing the amplifier went bad so I just unplugged the sub entirely waiting to be sent back to repair later.

Then one week I finally ditch my powerline adapter solution and replace it with a secondary router configured as a bridge to the primary router (i.e. the secondary router will connect to the primary router wirelessly and act as a bridge so it can serve internet connection to devices with wired connection connected to itself, which is exactly what you will accomplish with powerline solution but without pumping any signal going to the power line). I also upgraded my basic power strip with an APC surge protector with line noise filtration. I put the subwoofer back and I never hear the hum again.
 
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Re: How to solve speaker 'hum' due to powerline network

Mon May 23, 2016 3:32 pm

Besides the hacked-together solution I described above, moving to a proper A/V receiver also helped matters quite a bit. In fact, one I can be bothered one of these days, I'm going to go ahead and remove the power filters... if I haven't already but forgot about it.
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