Audio artifacts in recording

[naiqiy]

Hi everyone, I'm new to ProTools and recording in general. I did a multitrack recording of 16 channels (various instruments and vocals) in ProTools via USB from an Allen & Heath QU16 desk.

Listening back to the audio recordings, I noticed an audio artifact that I haven't been able to identify and hence haven't been able to find a solution to rectify the issue. Here are some tracks of the artifact (one at 0, one at +15, and one with keys playing): https://drive.google.com/drive/folde...usp=share_link

The artifact happens every other second and has a somewhat fixed rhythm to it. This "appears" on all the 16 tracks that were recorded and at the same time.

Would appreciate any insights into this issue and possible solutions.

Thanks.

Here's the signal flow:
Instruments/Vocals > Stage Box > Allen and Heath QU16 > (via USB) MacBook Pro (M1 Max, 32GB, macOS 12.3) > ProTools Artist (22.10.0.134)

[Darryl Ramm]

My first guess would be GSM phone interference. Get everybody to leave their phones turned off. Potentially check all your wiring/devices to work out where signals are getting in, electric guitar and bass are always leading suspects. If you are recording keyboard analog audio are you/should you be using a DI box/DI input and balanced audio cables.

[nednednerb]

Yeah, my guess is phone or wireless interference too of some sort.

I took a look at that audio in RX 10. Each click is not exactly the same in terms of bandwidth, duration, and dynamic. By that I mean, some are slight longer or shorter and have more or less level in different frequency.

Regarding that, I could use some automatic tools and manual tools to help a bit, but I think it would take hours and hours to work on a bunch of tracks like this, without any easy one button fixes. It could do in a pinch if audio quality didn't matter too much, but those keys sound nice, so the artifacts would be a crying, distracting shame.

I am quite confident it would likely never be totally perfect and the ordeal of attempting manual removal would therefore become very frustrating, circular, and unfulfilling.

Unfortunately, fixing the issue and re-recording is in your best interest, in my opinion.

[JFreak]

Originally Posted by Darryl Ramm

My first guess would be GSM phone interference.

This. And it reveals where you have saved pennies on cabling.

[BScout]

Originally Posted by JFreak

This. And it reveals where you have saved pennies on cabling.

No. GSM noise is often picked up by the copper traces inside equipment which act like an antenna for GSM frequencies. You can spend all the money you want on well-shielded cables or star-quad and it isn't going to eliminate that. The circuits themselves are the ones that are the issue (you could build faraday cages around all that equipment but that is a laborious task)

Best solution is to make sure GSM phones are kept far away from audio equipment.

[Darryl Ramm]

^^ Yes, it's not low frequency stuff like power line harmonics, or inductive motors noise etc. so can potentially get in anywhere, but sometimes single ended instrument cabling do help couple the RF signal in.

[naiqiy]

Thanks everyone for taking the time to check the audio sample out and for replying. They're really good insights. I have another opportunity to do a multitrack soon. I'll take the advice given and see what happens.