Hello everyone,

Yesterday I ran into a problem during a sound editing session. I was editing material in the low frequency range around 20-100Hz and noticed nasty clicks in my speakers. I then realized it's not only the speakers but all analog outputs including headphones.

I'm running the Fireface UFXII - USB 114 Model, FW 26, Driver 09840, TotalMix 1.93

I built a session to replicate the problem as follows:

- Cubase 13 Pro, White Noise Generator (Mono) sent to Output 6 (Output doesn't matter though)
- The White Noise sits at 0dBFS with an Equalizer (Highcut at 250Hz with a slope of 24dB per Octave) afterwards to make the clicks easily noticable

It appears the clicks start to come in at around -19dbFS (Channel Reading in TotalMix). Below that the signal seems to be clean. This means I can change the frequency content to whatever I want, as long as I hit the -19dbFS the clicks will come in. Although it's harder to provoke this effect with Sine Wave content. But it works with a 50Hz Sine Wave and moving the TotalMix Fader at around this -19dBFX Threshold.

Subjectively speaking it seems there is a climax in click density at around -16/-15 dbFS. Above that the clicks become less dense again and they almost disappear completely.

At this point, I'm sending the outputs, used for this test, to my Zoom F6 for monitoring and recording this phenomenon. I now took the signal and sent it via ADAT to my Behringer ADA8200 to bypass the Fireface DA Converters. Listening to the signal now, it seems completely clean no matter what the output volume.

Changing the Ouput Levels in TotalMix for the respective channel has an effect too. My default output level is -10dBV and with this setting the clicks are the most noticable. With +4dBu they are still there and with Hi Gain it seems like the clicks are gone but it's hard to tell.

To me this effect sounds closest to a samplerate problem. I double checked everything and everything is in sync - from the Cubase Session to the Fireface Samplerate and the Behringer Converter and the Zoom F6. Everything is running at 48kHz.

This Link leads to my cloud, where you can download the files I recorded with the F6.
https://mega.nz/folder/0c9H3Srb#2t0Dry0qIQP9-Phx1CYcHQ

I hope this explains everything in as much detail as possible and there's a solution to this!

Thanks in advance