As the last editing step on my LPs, I like to run Effect>Amplify to -0.5 dB (the default of 0.0 results in clipping, even w/o choosing to allow clipping). On single artist recordings I can usually do the entire LP at once, but on my compilation albums I usually have to apply the effect individually, since each title requires a different percent increase, ie, I can’t use CTL-R. This requires changing the amount numerous times.
Is there a way to get Amplify to remember the previous choice I entered? I note that some Audacity boxes do remember.
If by this you mean that you get red lines showing the clipped points you are both right and wrong. If you are seeing the red lines it is because you have activated “Show clipping” in the Preferences. What “Show clipping” does is to show you all the points where the sound has touched or exceeded 0dB. If you amplify to 0dB and any sample points do then sit at exactly 0dB, you will see red lines - but you will not yet have clipped the recording.
And rather than just using Ctrl+R to repeat the last effect - be aware that in 2.0.1 we introduced the ability for the user to define their own keyboard shortcuts for effects (for my LP transcriptions I have shortcuts set up for Amplify, Normalize, Fade-in and Fade-out - I find these extremely useful).
That’s true, but then we could get into arguments about “inter sample peaks” and the capabilities of DACs and so on. I prefer to normalize to a little below 0 dB. Apart from anything else, if your clear of the red lines then it is easy to see at a glance that you’ve not “overcooked” it. Right or wrong I find it reassuring to not see red lines
No arguments with that. When I first used v2.0 and discovered that it normalized to 0dB I was alarmed. I immediately set it to normalize to -1.0 dB in order to leave a little bit of headroom “just to be on the safe side”
CORRECTION: with Amplify the values are not remembered. When you invoke Amplify it calculates each time the amount it can amplify to take the maximum peak to 0.0 and then populates the dialog box with those values.
Apologies for the earlier misleading comment
TIP: this means that you can invoke Amplify to get the dialog box (and not do the amplification) to ascertain what the headroom in your recording is.
If you run the Amplify effect (Effect menu > Amplify), the amount of amplification before clipping is recalculated.
If you “Repeat Amplify” (Ctrl+R) then it will amplify by the same amount as last used.
For example, if you have 2 tracks:
Track 1 has a peak amplitude of -6 dB
Track 2 has a peak amplitude of -3 dB.
If you apply the Amplify effect to track 1, it will offer to amplify by +6 dB to make the new peak level 0 dB.
If you apply the Amplify effect to track 2, it will offer to amplify by +3 dB to make the new peak level 0 dB.
If you apply the Amplify effect to track 1, it will offer to amplify by +6 dB to make the new peak level 0 dB. If you then select track 2 and “Repeat Amplify” it will amplify track 2 by +6 dB and the result will be a peak level of +3 dB (if the track is 32 bit float format) or clipped by 3 dB if the track is an integer format (16 or 24 bit).
If you select both tracks and apply the Amplify effect, it will offer to amplify by +3 dB. (this is the maximum amplification that can be applied without any of the selected audio exceeding 0 dB or clipping).
Both tracks will be amplified by +3 dB, resulting in track 1 having a peak amplitude of -3 db and track 2 having a peak amplitude of 0 dB.