Audible hum using iems

May 16, 2022 at 5:26 PM Thread Starter Post #1 of 36

RoyDaniels

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Hello,

I've got this problem for a while now.
When I use over ear headphones I can't hear any noise but when using IEMs it's really annoying.
I use a JDS Labs atom+ stack and wanna use it with my Sennheiser ie 300s.

At first I thought that the stack is too powerful for iems but even when I use a cheap 30€ soundcard
I still hear that noise. I pulled every plug from my pc one by one to see what causes this and the result was that
the connection between my pc and dac / or just the usb soundcard conducts the noise to my iems.
And I've tried several other usb ports. The gain setting on the amp has no impact either.

I even hear the noise when I unplug EVERYTHING besides the connections to my Dac / soundcard
and turn my PSU off I still hear the noise, so it's not related to the electric circuit in my room.
The noise goes silent when I touch any metal that is connected to my pc, I guess everything conductable.
Means, when I touch my 6,3mm to 3.5mm adapter that goes into the amp, the cinch cable that is connected between my
Dac and Amp or even my condensor microphone, which has a metal chassis I guess.
Also what I didn't try until now was letting my brother touch the adapter and when he does, the noise remains, whereas when I do it, it disappears. So I guess I'm grounding myself?

What is also weird is that the noise is always on the right side of the earphone.
I even switched the iem housings to the opposite side (left housing on right the side of the cable and vice versa).
I tried my iems also on my brothers pc and of course my phone and there's no noise whatsoever.
So I guess the noise comes from inside my pc?
Thanks in advance
 
May 16, 2022 at 10:47 PM Post #2 of 36
I would guess there's a partial short on the IEM and/or cable shielding ('ground' in so far as earphones/headphones have it). IEMs are unique in that the shielding often contacts your skin directly (unlike on headphones where you generally have padding). This means when you touch the (likely fairly poorly) grounded case of your PC, your finger completes the loop and the IEM's sensitivity is such that you hear it. Some of the current going into the IEM's is conductively coupling to your skin, and in turn that flows on the PC case or electrically connected objects. You inferred this correctly yourself by testing with your brother touching the PC case (since he's not in contact with the IEM, there's no loop).

The good news is that your IEMs are probably OK if I understand your last comment correctly. If you mean to say that the issue always occurs on the right channel regardless of which IEM piece is plugged in (so when you have the 'R' IEM piece switched to your left, the issue occurs on the 'L' IEM piece you switched to your right, and also for 'R' right and 'L' left). This would indicate the parasitic short is on the cable/connector side and switching to a new cable ought to fix it.
 
May 17, 2022 at 1:01 PM Post #4 of 36
I would guess there's a partial short on the IEM and/or cable shielding ('ground' in so far as earphones/headphones have it). IEMs are unique in that the shielding often contacts your skin directly (unlike on headphones where you generally have padding). This means when you touch the (likely fairly poorly) grounded case of your PC, your finger completes the loop and the IEM's sensitivity is such that you hear it. Some of the current going into the IEM's is conductively coupling to your skin, and in turn that flows on the PC case or electrically connected objects. You inferred this correctly yourself by testing with your brother touching the PC case (since he's not in contact with the IEM, there's no loop).

The good news is that your IEMs are probably OK if I understand your last comment correctly. If you mean to say that the issue always occurs on the right channel regardless of which IEM piece is plugged in (so when you have the 'R' IEM piece switched to your left, the issue occurs on the 'L' IEM piece you switched to your right, and also for 'R' right and 'L' left). This would indicate the parasitic short is on the cable/connector side and switching to a new cable ought to fix it.
Thanks for the reply. I did have the ie 900 before and the issue was the same. I have another iem as well (Tripowin Mele) and I also hear it on the right channel, so while it might be that the cable doesn't shield, I doubt that a cable swap will fix it. Is there another way how I can "break" the loop?
 
May 17, 2022 at 1:36 PM Post #5 of 36
Thanks for the reply. I did have the ie 900 before and the issue was the same. I have another iem as well (Tripowin Mele) and I also hear it on the right channel, so while it might be that the cable doesn't shield, I doubt that a cable swap will fix it. Is there another way how I can "break" the loop?

Make your right ear less conductive lol? Seriously though you'll probably need to get a new PC case and/or switch over to battery powered sources like a DAP or a phone for your IEM needs if this is happening with multiple IEMs and cables.
 
May 17, 2022 at 5:26 PM Post #7 of 36
You could also just get a really cool pair of insulating gloves to wear while you use iems. The good thing is we're not talking about a lot of current here, iems are generally super sensitive.

Take care and good luck!
 
May 17, 2022 at 6:25 PM Post #9 of 36
Hello,

I've got this problem for a while now.
When I use over ear headphones I can't hear any noise but when using IEMs it's really annoying.
I use a JDS Labs atom+ stack and wanna use it with my Sennheiser ie 300s.

At first I thought that the stack is too powerful for iems but even when I use a cheap 30€ soundcard
I still hear that noise. I pulled every plug from my pc one by one to see what causes this and the result was that
the connection between my pc and dac / or just the usb soundcard conducts the noise to my iems.
And I've tried several other usb ports. The gain setting on the amp has no impact either.

I even hear the noise when I unplug EVERYTHING besides the connections to my Dac / soundcard
and turn my PSU off I still hear the noise, so it's not related to the electric circuit in my room.
The noise goes silent when I touch any metal that is connected to my pc, I guess everything conductable.
Means, when I touch my 6,3mm to 3.5mm adapter that goes into the amp, the cinch cable that is connected between my
Dac and Amp or even my condensor microphone, which has a metal chassis I guess.
Also what I didn't try until now was letting my brother touch the adapter and when he does, the noise remains, whereas when I do it, it disappears. So I guess I'm grounding myself?

What is also weird is that the noise is always on the right side of the earphone.
I even switched the iem housings to the opposite side (left housing on right the side of the cable and vice versa).
I tried my iems also on my brothers pc and of course my phone and there's no noise whatsoever.
So I guess the noise comes from inside my pc?
Thanks in advance
Sounds like one of the connectors is making contact between right channel and ground could be miss alignment or a single strand of wire may have come loose
 
May 17, 2022 at 11:13 PM Post #12 of 36
I've already unplugged everything and it still remained so that won't be it.
So the iems hum not connected to anything ?
The likely suspect is the trs jack since the right channel and ground are very close to each other so if the plug goes a fraction too far it will brush the right channel on the ground connection
 

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