• en5ca
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Topic: TotalMix FX Auto Level distortion

Hi! I'm getting subtle, yet audible distortion when using Auto Level function in TotalMix FX.

I'm taking 24-bit input signal via ADAT. In practice, I have no control over the level at source. In my situation, sometimes the input level is relatively low, closer to -40 dBFS RMS.

Using Auto Level function in TotalMix FX, I'm able to some extent 'dynamically' normalize the level to around -20 dBFS RMS with +18 dB Max. Gain, Headroom +12 dB and Rise Time 5.0s. But, as stated, this results in somewhat audible distortion. Even, when the source level is already closer to target, and Auto Level isn't doing much.

If I manually adjust the gain from dynamics with 1:1 ratios to bring up lower level material, I get no such distortion.

'Tightening' the Rise Time in Auto Level seems to make this a bit worse, but at any practical settings I'm not able get a clean sound with Auto Level.

Is this a common known 'feature' of Auto Level, I just have to accept? Using RME UFX+.

2 Reply by MC

  • MC
  • MC
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Re: TotalMix FX Auto Level distortion

Can you provide the original signal and the distorted one as small, several second long wav files for download?

Also define distortion. Any level controller adds 'distortion', as it dynamically acts on the signal, modifying it. Is that distortion as in THD, or as in amplitude modulation?

Regards
Matthias Carstens
RME

MC's Website

  • en5ca
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Re: TotalMix FX Auto Level distortion

MC wrote:

Can you provide the original signal and the distorted one as small, several second long wav files for download?

Also define distortion. Any level controller adds 'distortion', as it dynamically acts on the signal, modifying it. Is that distortion as in THD, or as in amplitude modulation?

Hi! Thank you for responding.

Not entirely sure how to define the distortion. Example files are with +18 db max gain, 12 db headroom and 1s rise time. I also might just have misunderstood the operation of Auto Level, and maybe it just operates a bit more heavy handedly than I assumed. Yet, similar difference test done with the regular TotalMix FX compressor yields cleaner results, even when set to fastest time values and highest ratio.

https://drive.google.com/drive/folders/ … qt9_XhOlCi

4 Reply by ramses (edited by ramses 2021-10-23 16:06:09)

  • ramses
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Re: TotalMix FX Auto Level distortion

> I also might just have misunderstood the operation of Auto Level

Maybe this thread from 2012 answers some or all of your questions: Thema: Auto Set & Auto Level - The Difference
https://forum.rme-audio.de/viewtopic.ph … 159#p69159

https://forum.rme-audio.de/viewtopic.ph … 160#p69160
Jeff: AutoSet acts on the preamp gain setting, Auto Level acts on the digital signal in TMFX.

https://forum.rme-audio.de/viewtopic.ph … 168#p69168
Jeff: Auto Level does not affect the recording level, only monitoring, as it acts on the signal inside TMFX.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
  • en5ca
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Re: TotalMix FX Auto Level distortion

ramses wrote:

> I also might just have misunderstood the operation of Auto Level

Maybe this thread from 2012 answers some or all of your questions: Thema: Auto Set & Auto Level - The Difference
https://forum.rme-audio.de/viewtopic.ph … 159#p69159

https://forum.rme-audio.de/viewtopic.ph … 160#p69160
Jeff: AutoSet acts on the preamp gain setting, Auto Level acts on the digital signal in TMFX.

https://forum.rme-audio.de/viewtopic.ph … 168#p69168
Jeff: Auto Level does not affect the recording level, only monitoring, as it acts on the signal inside TMFX.

Hi! Thank you for the hints, but I'm not sure if this is related. I'm not using Auto Gain, or gain for that matter (except for comparison). My 'issue' is that Auto Level seems to introduce more artefacts into sound than I expected when Auto Level has to work with extremes; e.g. to bring up 'obviously too quiet' material.

6 Reply by MC

  • MC
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Re: TotalMix FX Auto Level distortion

The Compressor settings used have a much higher release time, so there is less pumping in pauses. Else everything as expected. Just use what works better for the specific source. Extreme voice compression (here about 13 dB more volume) is surely not a good example of using the ALC feature.

Regards
Matthias Carstens
RME

MC's Website