1 Topic by Manuel (edited by Manuel 2022-01-04 01:46:36)

  • Manuel
  • Manuel
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  • Registered: 2007-10-03
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Topic: Pre-fader vs Post-fader loopback?

I have read the UFX II and UFX+ implement post-fader loopback, whereas the UCX II and the old UFX implement pre-fader loopback. I only have experience with pre-fader from the old UFX. This is a feature I use frequently so it's important to me. I'm a bit confused because it seems RME chose post-fader in their flagship audio interfaces (UFX II and +) and then they've gone back to pre-fader in the UCX II which was released afterwards, so I have a couple of questions:

1. Which is easier to work with? I have a feeling post-fader is not gonig to be very helpful because I might need to adjust the output level and that would affect the recorded audio (so what do I do, disconnect the monitors?), whereas the pre-fader signal wouldn't be affected and to me it would make more sense to record that.

2. Is the return to pre-fader in the more recent UCX II RME's way of saying "yup, pre-fader is officially the better implementation, we tested it in the UFX+ and II and we didn't like it, so we are bringing it back in the UCX II"?

2 Reply by ramses (edited by ramses 2022-01-04 07:21:26)

  • ramses
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Re: Pre-fader vs Post-fader loopback?

Only few people seem to have a real preference to use either loopback pre- or post-fade.
Most doesn't seem to have noticed that a difference in implementation exists and simply use it.

I also learned that one guy would like to use loopback post-fader, if I remember right to be able to record the exact output signal / with FX. So, tastes and demands are different.

-> https://forum.rme-audio.de/viewtopic.php?id=33261

To be honest, I can not even remember anymore, whether somebody asked or whether I stumbled over this topic "by accident" when reading several manuals to this topic (its documented in every manual, how the implementation is).

I mentioned in my blog article

-> https://www.tonstudio-forum.de/blog/ind … mentation/

about the different implementations, that post-fader could be a disadvantage if you have an active monitor connected to that output, as you might need to raise the fader to 0dB to "catch/record" the signal in full dynamic, but then it would be too loud. You would like to mute, but as soon as you mute, there is no signal to be looped back. So the only solution would be to disconnect the active monitor for the time being. But not every output has an active monitor connected, so you run into this problem only in this case.

But even this case could be solved by copying a submix to another output and to set fader to 0dB there and not to mute (because nothing has been connected), if you have a free channel to do so.

Ideal would be, IF technically possible at all, if RME would make the implementation of loopback switchable, then everybody could use, what he prefers and maybe best on a per channel base.

BTW I added the information which loopback implementation different recording interfaces have to make it easier to find, see: https://www.tonstudio-forum.de/blog/ind … B-MADIfac/
Direct Link to Excel: https://www.tonstudio-forum.de/index.ph … -04b-xlsx/ (see line 73 and 99 therein).

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13