Dealing with interference from computer monitors?

XtenanetX

XtenanetX

New member
So this might be a dumb question, but I haven't found a very good solution yet, so I wanted more professional advice.

I've noticed that when my two computer monitors are on, my guitars/interfaces pick up a lot of higher frequency noise/humming. The only real solution I've found so far is unplugging the monitors, but this seems like a waste of time when I just want to sit in front of my computer and record DI tracks quickly.

Is there any better way of blocking out this noise? I don't really have a lot of space to move far away from my computer (I'm just doing this in my bedroom).
 
What kind of monitors are they...LCD...or old school?
Also...are you using single coil pups or humbuckers...?...single coils pups are known for being noise magnets.

Anyway...it's not unusual for guitar pickups to be overly sensitive to some types of electronic equipment...so you may not be able to avoid all the noise...but it should only be if you come close to the equipment with the guitars.
If you're just getting noise even when standing across the room from the monitors...then there might be other issues involved, which take a bit of effort to resolve....checking for ground loops...isolating some of the gear on different circuits...employing some noise-filtering equipment...etc.

If you stand and turn in a circle with the guitar, can you find a sweet spot where the noise is almost gone?
 
Should have done a little more testing before posting this.

This noise seems to be a problem specifically with the audio interface/DI box. Even without anything plugged into it, there is mid to high frequency noise coming through.
I found that the "hum" could be removed by changing the position of the DI box (had it sitting on a receiver, may have been the issue). But this high frequency noise is still present.
I don't think this is a problem with the audio interface, since the noise was present on an old box I had, so I replaced it with a more expensive one, with no change in the noise. (Used to use a Behringer U-Phoria UM2, now I'm using a Yamaha AG03). I bought the DI Box (ARTcessories Zdirect?) also to try and solve this issue, but there really doesn't seem to be a change. Could there just be noise in the air? (if that makes sense)
 
XtenanetX said:
Could there just be noise in the air? (if that makes sense)
Click to expand...

Naaa... :)
Unless you live under a big radio station antenna...or some have industrial buildings with a lot of electronic equipment.

To me...that sounds more and more like either a ground-loop issue...or pure EMI (electromagnetic-interference) coming from one of the other devices.
I would certainly not put the DI box on top of other electronic gear for starters...then do some simple checking, one device at a time, and see if you can find the cause.

Also...If you have another guitar...have you tried it with the same DI box? It might be be a bad shield connection and when you plug it all together, it creates either a ground loop or the ground is broken, and the noise has no place to go.
 
You need to isolate the cause - if it happened with both interfaces, and there is noise even with nothing plugged into the interface, then change USB ports, USB cable, make sure you have anything with a wallwart or ungrounded AC plug plugged in the correct way. Are you using a laptop by chance? Their power supplies can be noisy.
 
Also . . do you have balanced leads going from interface to speakers?

That was an instant cure for the persistent PC noise my interface use to pick up
 
miroslav said:
Naaa... :)
Unless you live under a big radio station antenna...or some have industrial buildings with a lot of electronic equipment.

To me...that sounds more and more like either a ground-loop issue...or pure EMI (electromagnetic-interference) coming from one of the other devices.
I would certainly not put the DI box on top of other electronic gear for starters...then do some simple checking, one device at a time, and see if you can find the cause.

Also...If you have another guitar...have you tried it with the same DI box? It might be be a bad shield connection and when you plug it all together, it creates either a ground loop or the ground is broken, and the noise has no place to go.
Click to expand...

I have everything plugged into a power conditioner so ground loops shouldn't be a problem right? Also, I had tried the old interface with nothing but the essentials connected to the computer and it made no difference. Also, shouldn't be a problem with the usb cable because I've tried multiple, and the port shouldn't be an issue because I used to have a different motherboard and it was the same.
 
mjbphotos said:
You need to isolate the cause - if it happened with both interfaces, and there is noise even with nothing plugged into the interface, then change USB ports, USB cable, make sure you have anything with a wallwart or ungrounded AC plug plugged in the correct way. Are you using a laptop by chance? Their power supplies can be noisy.
Click to expand...

It's a desktop, and the USB port shouldn't be the problem because I've changed motherboards since I started trying to troubleshoot this. I've also changed USB cables
 
XtenanetX said:
I have everything plugged into a power conditioner so ground loops shouldn't be a problem right? Also, I had tried the old interface with nothing but the essentials connected to the computer and it made no difference. Also, shouldn't be a problem with the usb cable because I've tried multiple, and the port shouldn't be an issue because I used to have a different motherboard and it was the same.
Click to expand...

No, you could have a ground loop after the power conditioner.

It is the items that are plugged into the USB cable that cause the loop not the cable itself, the usb cable becomes the ground route.

If you are using a DI, are you using balanced XLR cables between the DI and the interface? If so have you tried the ground lift on the DI?

Alan.
 
witzendoz said:
No, you could have a ground loop after the power conditioner.

It is the items that are plugged into the USB cable that cause the loop not the cable itself, the usb cable becomes the ground route.

If you are using a DI, are you using balanced XLR cables between the DI and the interface? If so have you tried the ground lift on the DI?

Alan.
Click to expand...

And This ^^^
 
gecko zzed said:
Also . . do you have balanced leads going from interface to speakers?

That was an instant cure for the persistent PC noise my interface use to pick up
Click to expand...

Excuse me for my lack of knowledge, but I'll give you a run down of my audio output situation.
I have my default device set to my audio interface, which I then have the regular red/white left right audio outputs plugged into the left right auxilery port on the back of an audio receiver, which is then connected to home theater speakers with regular speaker wire
 
witzendoz said:
No, you could have a ground loop after the power conditioner.

It is the items that are plugged into the USB cable that cause the loop not the cable itself, the usb cable becomes the ground route.

If you are using a DI, are you using balanced XLR cables between the DI and the interface? If so have you tried the ground lift on the DI?

Alan.
Click to expand...

My interface is connected to the PC with USB, and the DI box is connected to the interface via XLR. I have used the ground lift, but I actually noticed a new hum tone added to the white noise that was already present when this was enabled
 
XtenanetX said:
Excuse me for my lack of knowledge, but I'll give you a run down of my audio output situation.
I have my default device set to my audio interface, which I then have the regular red/white left right audio outputs plugged into the left right auxilery port on the back of an audio receiver, which is then connected to home theater speakers with regular speaker wire
Click to expand...


Not possible to accurately call that the problem issue, but it damn likely...
 
jimmys69 said:
Not possible to accurately call that the problem issue, but it damn likely...
Click to expand...

I realize that this set up is pretty stupid, but to be fair, I did still have this issue with regular computer speakers in the past. Plus, fact I just remembered, I believe that there was actually noise that would come out of the speakers without anything playing. Could there just be noise inside my computer itself that is affecting everything?
 
XtenanetX said:
Excuse me for my lack of knowledge, but I'll give you a run down of my audio output situation.
I have my default device set to my audio interface, which I then have the regular red/white left right audio outputs plugged into the left right auxilery port on the back of an audio receiver, which is then connected to home theater speakers with regular speaker wire
Click to expand...

The inputs if the receiver is most likely unbalanced RCA connectors. Not a problem but makes it harder to solve your problem. There can be 2 places where you have a grounding problem, between the interface and the computer, or the interface and the receiver. Also computer and receiver but this would be via the interface anyway.

For a small cost I would put one of these between the interface and the receiver and see if the problem goes away. This device also converts balanced to unbalanced and vice versa.

Alan.
 
This..AV Link High Quality Ground Loop Isolator Noise Reduction Filter - AV Link from Inta Audio UK
Is cheap, works surprisingly well and has the RCA connectors you need. But I notice that Yamaha AI is a "generic usb device" ? At least I am guessing it does not have dedicated ASIO drivers. This means you need to set the recording gain (and possibly playback level) up in the Windows Sounds Menu.

Find the device, probably be called "Microphone CODEC" or some such, make it the default recording device (be wary the laptop internal mic is not on!) and then check the Level tab. My bet is this will be at 100% far too much gain. Try 5 yes! Five % or even lower (but 0% gives you FA!) You want average picking to give you around -18 to -16dB on the meters. This is a higher than desirable level but I am sure the AI is a 16bit only device. Do not stray higher than -6dB ever because these cheap (WTGR!) AIs have little headroom.

The playback level might be a little high as well but you can tell from how far you have the volume knob advanced on your receiver. When playing -16dB recordings you should have it a bit past 12 o'clock.
Unfortunately YooToob sound will be slammed so you will need to back it off for that.

Dave.
 
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