Hi there, normally of course I could easily reduce volume in Audacity with amplify -dB. But since I’ve been trying to do things with more than one or two tracks, it’s not always easily working. It seemed to work for a while but now it’s started failing again.
I reduce amplification, it could also involve reducing to -14 LUFS or whatever they are as I’ve heard that should help. But it doesn’t seem to.
It looks find but if I close the file and reopen it it’s a rectangle of pure blue again.
It also sounds fine in audacity. But if I try to upload it anywhere at all it’s a mess of loud squeaks and crackles and can’t be used. Hope you can help.
Set Audacity to show clipping (View → Show Clipping In Waveform).
The Loudness Normalization effect allows you to set the LUFS level. But you have to check for clipping of the peaks and you may have to lower the volume below your -14dB LUFS target (or use Limiting) before you export.
By default, the Amplify effect won’t allow clipping but Loudness Normalization or other effects don’t check the peak levels.
If you run Amplify or Normalize with the defaults before you export you will be OK but of course that will change your LUFS level too.
Audacity uses floating point internally which means it can go over 0dB without clipping, and if you aren’t playing-back at “full digital volume” you may not be clipping your DAC and it can sound OK. But if you export as a regular (integer) WAV file it will be clipped.
Regular WAV files, audio CDs, your ADC (recording), and your DAC (playback) are all limited to 0dB. 0dBFS should be considered the “digital maximum” and your final production shouldn’t go over 0dB even if you’re using a format that allows it.
Show Clipping is actually showing potential clipping and you can get false positives and false negatives. For example, you can boost the bass and you might “see red” but it’s not clipped yet and you can run Amplify to lower the volume and it will be OK. Or your imported file will probably “show red” and you can run Amplify to lower the volume so it no longer shows red. But the distortion is still there.
I don’t understand any of that, sorry.
As far as I know Audacity isn’t doing any clipping of it (for which I’m glad.) But when I upload it to other sites they can’t work with it.
It is now I’m making things with about 3 tracks in that it’s struggling to make it in an uploadable form that works. Any ideas?
I’m uploading as mp3 because I’m used to that.
If you’re so kind as to explain what I need to me, please explain it as if it were to a munchkin.
It looks badly clipped. And you’re saying it sounds distorted…
If you are mixing 3 tracks, that would explain it. Mixing is done by summation.
…Analog mixers are built-around summing amplifiers but they have a volume adjustment for each track plus one for the master/mix so it’s more of a weighted average than a pure sum. Full DAW applications also have faders & meters for each track, plus on the master.
One way to fix that is to export as 32-bit float WAV. Then re-import and Amplify or Normalize to bring-down the volume before exporting to your final desired format. Or you can try Loudness Normalization if you check for clipping.
Or you can try lowering the tracks by about 70% (-10dB) before mixing. But I don’t know where you’re starting and it depends on where the peaks line-up so the 2-step floating point method is better.
Ooh I’ll have a go, thanks. Wouldn’t normalizing last? I open my mp3 in Audacity again at some point and it’s back to being a blue rectangle again even though it looked fine when I deamplified and maybe loudness normalized, then saved it.
Yes it will “stick” but you have to normalize after mixing. Normalizing is usually the last step and sometimes it’s an “extra step” after temporarily exporting to floating-point.
A couple more things -
Mp3 is lossy compression. The wave shape changes and the highest-peaks often end-up about 1dB higher. Even if your original doesn’t clip, the MP3 can… If the original isn’t clipped the MP3 won’t actually be clipped… MP3 can go a little over 0dB without clipping. But if somebody plays it at full volume they will clip their DAC. And if you import it back into Audacity it might show red for (potential) clipping.
Sometimes people normalize for peaks at -1 or -2dB to prevent that. Personally, I don’t think the slight clipping is audible and I don’t worry about it.
Regular volume adjustments are linear… If you lower the volume by 3dB, the peaks, LUFS, and RMS all go down by 3dB. That’s true whether you Amplify, regular peak-normalize, or loudness normalize… Everything changes by the same dB amount. (Of course if you amplify into clipping, the peaks can’t go up anymore and the adjustment is no longer linear.)
Hi there, I’ve saved as a WAV and done some other stuff and now I’d like to do the Limiter.
Please could you let me know what settings to put as a first pass over something before you would try again or a plan B?
It would be so helpful if you could let me know.
Normalize or run Amplify to make sure the level is good. That also gives you a good starting-point for the limiter.
Are you sure you want limiting?
I haven’t used the “new” limiter and it looks like they’ve changed it again (making it more understandable).
The threshold is the limit. A threshold of -3 or -6dB is probably “reasonable” to start with. If you want it “louder” you can run it again. If you over-do limiting it starts to sound like distortion.
You’d typically set the make-up gain the same as the threshold, so the peaks are back where you started, but the “loudness” and LUFS will be higher…
As an alternative to make-up gain you can Amplify or Normalize again after Limiting.
P.S.
When I say “normalize” I’m talking about regular-old peak normalization. I’m not talking about loudness normalization.
If you need 14dB LUFS, you can use a different procedure - Loudness normalize first, and then run the limiter with a threshold of 0dB (or maybe -1dB) and no make-up gain. A little limiting (without make-up gain) won’t change the LUFS much. (But you’ll have to listen to make sure it doesn’t sound distorted or over-compressed/over-limited.)
