I was wondering if you would be able to elaborate a little about the control "RMS average" control which is used in Digital Peak Meter Pro and dynamics . I understand that this effects the rms half of the envelope follower ( some call it envelope detector).
The manual simply states that this control controls the RMS computation time.
IS this similar to "windowing " in FFT?
I noticed that if I watch the resultant envelope in DPMP and increase the time used that the resulting envelope is much more smoothed out an moves farther and farther away from the representation of the peak .
I understand that RMS is all about averaging and that this result is to be expected . What I am curious about is ...
1.) Can you tell me what the reasoning was behind the choice of the default value ?? ( 500ms on DPMP and 700ms in dynamics)
2.)Is there any relation ship to how the settings on the RMS envelope follower will be sensitive to different frequencies Dependant upon the window /time settings ???
3.) and "rule of thumb" you might recommend when setting this control ?? ( besides the usual "use you ears" retort !!!.
Thank you
Question about RMS size
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Blue Cat Audio Blue Cat Audio https://www.kvraudio.com/forum/memberlist.php?mode=viewprofile&u=39981 - KVRAF
- 6349 posts since 8 Sep, 2004 from Paris (France)
Hi,
the rms average parameter indeed controls the length of the RMS window. The RMS envelope is an average. Setting this length is equivalent to setting the attack and release times for a peak envelope follower, except that for RMS it's symmetrical (hence the single value). That's why higher values results in smoother envelope.
1) The default value is different on both plug-ins because for the DPMP it is mainly used for visualization. That's why we chose a shorter value. On the Blue Cat's Dynamics plug-in 700 ms is a long enough value for a smooth average and it lets you hear clearly the difference with the peak mode.
2) In most signals there are many harmonics so that there is no audible relationship between the length of the RMS window and the frequency content (the RMS average works in the time domain). The rule of thumb is that the longer the rms window, the smoother the envelope, that's it.
3) The RMS envelope is used to detect loudness (as opposed to peak envelope for peaks). So in most cases you will be using rather large values (compared to peak). In some particular cases you will want to decrease the length of the RMS window for an envelope closer to the peak envelope, but with the RMS shape (if you look at the shape of the RMS envelope in the DPMP, it is very different from the peak envelope). Typically, RMS compression will be used for "leveling", so you will want to adjust the rms window to the appropriate length for your material: short if you want the compressor to adjust the level very often, and long if you want to make the compressor respect the original loudness of the sound.
Hope this helps!
the rms average parameter indeed controls the length of the RMS window. The RMS envelope is an average. Setting this length is equivalent to setting the attack and release times for a peak envelope follower, except that for RMS it's symmetrical (hence the single value). That's why higher values results in smoother envelope.
1) The default value is different on both plug-ins because for the DPMP it is mainly used for visualization. That's why we chose a shorter value. On the Blue Cat's Dynamics plug-in 700 ms is a long enough value for a smooth average and it lets you hear clearly the difference with the peak mode.
2) In most signals there are many harmonics so that there is no audible relationship between the length of the RMS window and the frequency content (the RMS average works in the time domain). The rule of thumb is that the longer the rms window, the smoother the envelope, that's it.
3) The RMS envelope is used to detect loudness (as opposed to peak envelope for peaks). So in most cases you will be using rather large values (compared to peak). In some particular cases you will want to decrease the length of the RMS window for an envelope closer to the peak envelope, but with the RMS shape (if you look at the shape of the RMS envelope in the DPMP, it is very different from the peak envelope). Typically, RMS compression will be used for "leveling", so you will want to adjust the rms window to the appropriate length for your material: short if you want the compressor to adjust the level very often, and long if you want to make the compressor respect the original loudness of the sound.
Hope this helps!
