Academy Dashboard Forum Production Digital Recording A very basic question about recording levels (gain, peak, rms)

  • This topic has 2 replies, 3 voices, and was last updated 1 year ago by Donald MacTavish.
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  • #90530
    Camilo Flores
    Participant

      So, I have a very basic question and I haven't been able to find an answer.

      I used to record without worrying about level and db and gain, etc just focusing on how good it sounded and afterward controlling the volume by lowering the faders (I use Logic by the way).

      Now that I'm starting to consider self-producing/mixing my own songs I'm beginning to see a lot of information but I haven't seen this (I guess) very basics doubts that have been plaguing my mind.

      1.- When you talk about gain staging at per example -12db per track, does that means that when I'm about to record should I move the gain knob of my interface (Scarlett 4i4) until in the Logic track (using the pluging Level Meter) I got a Peak at around -12 db? And I have to achieve this with all the instruments and voices I'm recording? Or for example, can I record more hot, avoiding clips and whatsoever and then just move the volume fader until it says in the little square above -12db?

      2.- What is RMS? In this forum someone mentioned that in a question about gain staging and I've been searching and I kind of get that is like a metering of "average loudness" rather than the peak stuff but I'd like to understand the concept in terms of recording and mixing. Should I gain stage based on RMS and not on Peak (Thinkin' about the Logic plugins for Metering)?

      Thanks you in advance

      • This topic was modified 3 years ago by Camilo Flores.
      #103967
      Eddie Lagos
      Participant

        I'm wondering the same thing, especially about #1

        #103970
        Donald MacTavish
        Participant

          Hi

          Gain staging is critical to prevent overloading the channel or the mix bus.  Originally it was based upon the optimal levels for analogue gear to prevent undesirable distortion.  If you use any plugins that are modelled after analogue gear gain staging is even more critical.

          Here is some basic math to help you understand the topic:

          1.23 volts = +4 dBu ( referred to as reference level for balanced xlr signals ) = 0 dBVU (RMS) = -18dBFS  ( Digital )

          RMS means Root Mean Square and the math is RMS / 0.707 = peak value Zzzzzzz...

          Best way to understand this is to add a Meter plugin and set for RMS and PEAK.  Watch how they respond to the signal, peak will be higher.  RMS is an average over time as opposed to short term peaks.

          The goal of gain staging is to make sure that the signals are at ideal levels for mixing. As a *basic guide* you should be sending tracks to the mix with peaking between -12 and -18 dBFS so the mix bus does not become overloaded. If you have 2-4 tracks this is manageable but if you have 20 - 100 the solution is with sub-mix busses to maintain control and sanity.  If every track is peaking at -1 dBFS the sum on the bus will be in the red. ( History: Analogue mix desks were happiest with the faders around zero and the faders taper allowed finer adjustments +/- zero... nerd out!) )

          You want to monitor peaks since they are the highest level for the signal. In Logic the little box you mention is the peak for the track.

          To address your questions 1):

          1) Try to record all audio with peaks around -12 to - 18 dBFS ( no plugins impacting the signal ). This will give you lots of headroom to add plugins and manage gain staging. Use the preamp in your interface as well as instrument volume controls to set the signal.  The "fader" in Logic has no impact on the recording level.  As you add plugins watch the gain if if a plugin is adding lots of gain manage that with the different "gain" controls for the plugin. For software instruments the same is true and you often need to turn the "volume" control down a bit.

          2) I think I answered above.

          Lots of good tutorials on YT about gain staging that can help you understand the topic. Once learned it becomes second nature.  Avoid tutorials that push everything into the red and advise to make it "loud".  Personally I have found the more you learn and understand analogue techniques the better your digital outcomes.

          Prost

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