[SOLVED] Some sort of audio interference ?

[BlitzkriegPotato]

I have a bit of a weird setup going. The overall goal is to have two PCs partially sharing audio. The ideal setup is to have PC1 recieve all audio from PC2, but PC2 only receives the audio from the mic attached PC1. I have gotten this to work, but I get a lot of interference. I am far from an audio expert so I have no idea what kind of interference this is (Audio sample in youtube video below). I would like to know if there may be something inherent to my setup that would cause this, or otherwise a way to filter out the interference.

The primary issue is the audio coming from PC2 speaker port (combo speaker/mic?) to PC1 line in, so everything below, unless otherwise specified, is referring to that.

Sample of interference:

View: https://youtu.be/AoGPely77v0


The "Sabrent" mentioned below is this: https://www.amazon.com/dp/B00IRVQ0F8
PC1 has a USB DAC for my headphones and mic.
PC1 Line in is connected to PC2 Sabrent USB speakers (combo port?) with a 3.5mm cable.
PC1 is set to "listen to" line in and playback through the USB DAC with windows control panel sound.

I have tried using Equalizer APO, following this video(

View: https://youtu.be/hXstcXqNvPo
) which does negate most of the noise, but only when applied to my USB DAC (an output), which effects all audio, and is something I don't want. Sadly when applying it to Line in, nothing happens, which must mean windows listen/playback happens before Equalizer APO can do its thing.
Latency is not an issue, as long as it is consistent, as voice, and in theory only voice, will be coming in on line in.

Please do let me know if more details and what additional details would help.

 

[JWNoctis]

Cannot watch any of that video due to a connection problem on my end. But if I have to guess, your setup has a ground loop.

Break that with either a S/PDIF connection, or a ground loop isolator. But do read up on both first, and I myself have zero practical experience with either.

 

[BlitzkriegPotato]

Cannot watch any of that video due to a connection problem on my end. But if I have to guess, your setup has a ground loop.

Break that with either a S/PDIF connection, or a ground loop isolator. But do read up on both first, and I myself have zero practical experience with either.

It does appear to have been a ground loop. An inline ground loop noise isolator sorted it in one direction so I ordered another for the opposite. Thanks for the help!