1 Topic by Emirb (edited by Emirb 2020-06-24 11:18:08)

  • Emirb
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Topic: What reference level should I use?

Hi,

I was reading the manual (yepp it is true smile) for my RME UC and I am a little curious to know what reference level I should use. (Lo Gain, +4dBu or -10dBV)

I am mixing 100% ITB.

I make some analog recording, acoustic guitar, Moog sub phatty, vocals. (Preamp: Avalon VT737SP)
I use Cubase 10, the Avalon is connected to rear intput (one of the 5-8 intputs, cant remember exactly).

I really dont know what reference level is right for me and the way I work? Is there a right or wrong? And why are there options here?

2 Reply by ramses (edited by ramses 2020-06-24 11:55:54)

  • ramses
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Re: What reference level should I use?

The analog inputs and outputs of different devices are designed for different use cases.
There are analog ports which are desiged to work at lower consumer levels, which you can find e.g. at HiFi devices (cinch).
There are also analog ports which are designed for studio work where cables usually can get longer why signals work at a higher level and balanced cables are in use.

You device gives you the possibility to select a proper reference level to achieve two things

a) to match with the level of the other side of the cable
it makes neither sense to overload the other circuit, not to send it a too weak signal, so that the other circuit can't work in an optimal range for best SNR and dynamic

b) to make it possible for AD/DA converter to work at optimum SNR and dynamics

Look e.g. at this Excel, how many dB SNR you can loose if you operate your device at a suboptimal reference level:
https://forum.rme-audio.de/viewtopic.ph … 24#p155724

There is also a nice example regarding this in the ADI-2 Pro/DAC manuals, see ch 21.3 here:
http://www.rme-audio.de/downloads/adi2profsr_e.pdf

There are devices that allow you to set the reference level per port or only for a whole bunch of inputs or outputs.
Some devices support up to 4 different reference levels which gives much flexibility.

In your use case you most likely only have to take care of phones and monitors.

For phones you will most likely not need the highest output, so that you can turn the faders towards 0dB in a range between approx -30 - -10 dB. Depends of course on your phones (impedance, effectivenes of drivers).

For monitors you also might need to use the lowest output level, so that 0dB do not roast your ears or speakers.

See also this interesting article from Matthias Carstens about level matching:
https://forum.rme-audio.de/viewtopic.php?id=25399

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

3 Reply by fl (edited by fl 2020-06-24 14:03:43)

  • fl
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Re: What reference level should I use?

For your Analog Inputs, do you only use the Avalon pre-amp or the synth? It might be an idea to plug the Moog Phatty into Input 1 or 2 on the front panel, with the UC's mic pre gain turned all the way down and then brought up to where it's an acceptable level (be sure that Phantom power it turned off too), rather than one of the fixed 1/4" TRS inputs on the front or back. The Avalon should go into the rear Inputs, as you have done already.

It's very likely that for the Avalon, the proper Input Gain setting on your UC will be +4 dBm, although you might want to try the "High Gain" setting and then turn the Avalon's gain down to compensate, and see whether you get lower noise overall with this setting. If you're using a microphone which requires a lot of gain, like a Shure SM7, or almost any other dynamic mic, you could play with this to see which gives you the lowest noise on your recordings. Things might be pretty quiet already, so for testing, carefully turn up your monitors to a level where you can hear the noise floor, and then see which gives you less (or nicer sounding, at least) - Avalon with higher gain with the UC at +4, or Avalon lower with UC at "High Gain".

For the Analog Outputs, that well be determined by what you're feeding signal to for monitoring. Most self-powered speakers are looking for +4 dBm (although some are switchable), although some additional level control is useful for your speakers so you can turn things up and down, whereas most consumer hi-fi amplifiers already have Volume Knobs, and want to see -10 dBu at their inputs.

Frank Lockwood
https://LockwoodARS.com
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