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;version 4
;control target “Target RMS level” float “dB” -20 -40 -6
;control mode “Normalize stereo channels” choice “Linked stereo,Independently” 0
(setf target (db-to-linear target))
(defun mean-sq (sig ln)
(let ((j 1) (total 0))
(when (> ln 1000000)
(setf j (round (/ ln 1000.0)))
(setf ln 1000))
(setf msq (snd-avg (mult sig sig) ln ln op-average))
(dotimes (i j)
(setf total (+ (snd-fetch msq) total)))
(/ total j)))
(defun rms-mono (sig target ln)
(mult sig
(/ target (sqrt (mean-sq sig ln)))))
(defun rms-stereo (sig target ln)
(mult sig
(/ target
(sqrt (/ (+ (mean-sq (aref sig 0) ln)
(mean-sq (aref sig 1) ln))
2.0)))))
(if (= mode 1) ;independent
(multichan-expand #'rms-mono track target (truncate len))
(if (arrayp track) ;joined stereo
(rms-stereo track target (truncate len))
(rms-mono track target (truncate len)))) ;mono
\
The above I’m calling “SetRMS” for lack of a better name. It directly adjusts RMS (Loudness) to ACX without all this beating about the bush with other tools.
In the above message, it’s all the text without the top and bottom blank spaces and equal signs. You will need to drag-select the text (computer code) and Copy it using your computer Copy command.
– Open DB Chapter 1 Edited.wav in Audacity.
– Select it all by clicking just above MUTE.
– Effect > Nyquist Prompt > Paste > OK. The little window should fill up with lots of parens, punctuation marks and semi-English words. > OK.
– Target RMS -20.00, Linked Stereo > OK.
– The show will sit there staring blankly at you for quite some time, but in the background, SetRMS is pounding away figuring out where to put the corrected blue waves. I have a reasonably fast machine and it took 20 seconds. If yours is slower, you may be able to make tea.
If you get a response panel or other error message, it failed.
The blue waves will get much taller and some of them may expand off the timeline window. This is normal. If you have View > Show Clipping enabled you will see a forest of thin red warnings. That’s normal, too. I’m using Audacity’s odd ability to gracefully manage over-range sound without damage.
– Effect > Limiter: Soft Limit, 0.00, 0.00, -3.50, 10.00, No > OK.
Limiter is a more finished tool than SetRMS. It has an annunciator panel and will tell you where it is in the process.
– Analyze > ACX Check.
Listen around 10 minutes at “Rob? You called him Rob!!” That’s where the tools had to do the most work. That was your theatrical expression phrase.
Koz