Sound distortion from PA to line in on PC

Question

I was recently voluntold to figure out how to stream live services for our church to Zoom. I have things working pretty well by using the line out from the PA system to the line in on the PC with a 3.5mm audio cable. This is an older laptop we are using, so it actually has a separate line in from the microphone jack.

The problem I am having is with loud voices or people standing close to the microphone. On the PA system, they sound just fine, but on the PC feed and for those watching on Zoom, it sounds like they are blowing out the speakers. If they were to step back from the microphone a bit, or even point it down, it sounds just fine. This is especially problematic for musical numbers. When the singer hits the loud notes, it sounds horrible.

Is there anything I can do from a Windows 10 software mixer perspective? Or is this a hardware issue?

Answer 1

In my experience this is a hardware issue. The sound is when the input hardware of the PC getting too hot signal and clipping. The first step to try then is to decrease the "gain" of the signal going into the PC. There migth be a volume control on the line out or something similar.

A probable better solution is to purchase a simple external sound card for the PC. Check brands such as Behringer for exempels.

You might notice that the Zoom will vary a lot in volume because the speakers are not at the same distance from the mic. This matters less in the room with the PA as there you can hear the direct sound. But on the internet feed this can become quite annoying. One solution to this is add a component called "compressor" in the signal chain. There are hardware compressors you can buy. It is possible for the mixer person to "ride the faders" in order to kompress. There are software compressors as well, but I am not sure if they can be used together with ZOOM.

I used to have a small combined mixer with USB outputs that had compressors in the input channels. You might search for something like that as a solution. Maybe something like the Behringer Xenyx Q802USB. Note this is not a recommendation as I have not used that exact unit, only a pointer in direction.