Like many, I have SHOW CLIPPING turned on, which display clips in RED.
When editing an audio, sometime I only reduce overall Gain (like with Ctrl+A) by 0.25 or 0.5 dB and then fix CLIPS with the Pen Tool one at at time. What about a function find next clip´ and then another function zoom in to clip´ or `zoom in to sample´ so you can go right to work with the pen tool. That would greatly speed-up manual Pen Tool fixing across the audio.
Thanks,
-Ed
If you have to fix clipping frequently, you’re doing something wrong. Why is clipping a frequent problem for you?
Oh, well I’m sent MP3 lectures to edit for uploading and many of them are clipped. Also I record and monitor radio shows real time using VLC player as a receiver and Audacity as a recorder. The gain (volume) settings are adjusted to accurately monitor (so I believe) their shows, with the ability to send real time level feedback via IM.
So there are several reasons. I HATE to amplify (attenuate) the whole file just because some peaks are 1-2 dB above the `rails´. Hence attenuate file by 0.25 to 0.5 dB which takes care of most clips, and then fix remaining clips with pen tool. Thing is, it’s a LOT of mouse wheeling to zoom in on each clip. For badly clipped sections, I use Selection tool, zero crossing, amplify (attenuate)
So how about a find next clip and zoom in to clip? 
-Ed
How about using Soft Limiting to bring everything close to the rails without affecting the overall volume? This is the final step in the AudioBook mastering suite. Rumble Filter, Set Loudness and gently roll down (limit) all the tips that go over.
People are producing paid audiobook work with those corrections.
The suite has you limiting to -3.5dB because that’s the requirement for audiobooks plus a little safety. You can put that step at whatever value you want, but note conversion to MP3 can create peak distortion.
http://manual.audacityteam.org/man/limiter.html
https://forum.audacityteam.org/t/audiobook-mastering-version-4/45908/1
Koz
and then fix CLIPS with the Pen Tool one at a time.
Are you actually hearing distortion, and are you making it sound better? Or, are you just making yourself feel better?
Audacity doesn’t really know if you have [u]clipping[/u]… It warns you of potential clipping.
As you probably know, MP3 is lossy compression. When you open it in Audacity (or any “normal” audio editor) it gets decompressed. If you then re-export to MP3 you are going through another generation of lossy compression and the “damage” does accumulate. You may not hear any quality loss but that’s something to be aware of. But, you could end-up with worse sound after trying to fix it. If you’re not re-exporting to a lossy format, that’s not a problem… the 1st generation damage was already done. Or if you have to edit the files anyway, you can’t avoid it.
You could also make the sound worse by re-drawing the waveform. Judge the sound by how it sounds, not by how it looks! 
As Koz says, MP3 will “distort” the peaks (it actually slightly changes the whole wave shape). That makes it difficult to automatically find clipping:
1. Truly clipped waves are no longer totally flat-topped (and flat-bottomed) after MP3 compression.
2. MP3 can go over 0dB without clipping.
3. MP3 compression makes some peaks higher and some peaks lower (without causing clipping). If you rip a CD and make and MP3, or download an MP3 from Amazon, it’s not unusual to get peaks over 0dB and Audacity will show red (potential clipping).
Audacity uses floating-point “internally” so Audacity has virtually no upper (or lower) limit and it also can go over 0dB without clipping (but it will show red).
…If you play the over-0dB MP3 at full digital volume, you will clip your DAC (which is hard-limited to 0dB) but I’ve never heard of a case where that slight clipping was audible. WAV files and CDs are also hard-limited to 0dB so they will clip if you “try” to go over.
Some people do normalize to -1dB or so before MP3 compression but I don’t worry about it.
So there are several reasons. I HATE to amplify (attenuate) the whole file just because some peaks are 1-2 dB above the `rails´.
If it’s going over 0dB, it’s obviously not clipped at 0dB. It could have been clipped during recording, but can be hard to tell without zooming-in and looking at the waveform (after attenuating it so you can see the over-0db peak).
If the file is truly clipped, reducing the volume won’t fix it. Attenuation doesn’t change the wave shape. But if you reduce the volume, Audacity will no longer show real or potential clipping.
What about using Clip Fix (http://manual.audacityteam.org/man/clip_fix.html)?
It won’t help with badly clipped audio, but for minor clipping it will probably do a better job than drawing by hand, and certainly be very much quicker.
That was a good read, and I understood all of it. Yeah… pretty much obsessed with getting rid of Audacity RED marks.
The thing is… the guys are producing their shows with low-end software. See Butt software… https://danielnoethen.de/ – and their levels are ALL over the place. They don’t understand or use limiter/compression plugins, and the show dynamic range can be dreadful, i.e. very low passages and grossly over driven spots.
And I have to review these and `clean them up´.
-Ed
I tried out the Limiter function last night and it worked Great the first time!
Before:
After:
Here are the settings:
The two Effects that have, or will save the most time are Truncate Silence and now Limiter.
Thanks,
-Ed
Since your goal is entertaining production with as little distortion as possible but nobody is going to shoot you if it’s a little off, you may be the customer for Chris’s Compressor. This is a stand-alone show processor that can closely approximate broadcast compressors and processing.
I used to record a radio show off-air in Los Angeles and I would just change the overall volume a bit to listen while hiking. Full stop. They started to offer the show as an on-line download and it didn’t have the FM radio background noise and other distortions. But it didn’t have the broadcast compressors, either and it was almost unlistenable from the terrific volume swings between the performers. One mumbled in his beer and the other had a laugh that registered as an earthquake event by seismometers .
Does that sound like some of your shows?
I change the first value Compression ratio from 0.5 to 0.77 and the show is very nearly identical to the broadcast version. No further effort needed.
https://theaudacitytopodcast.com/chriss-dynamic-compressor-plugin-for-audacity/
There is one known problem. It’s a look-ahead compressor and it doesn’t like the end of the show because it doesn’t have anything to look ahead to. Make sure there’s some show or other sound “sticking out” past the end before you run Chris. Then you can cut it off.
I just used to not perform the last trim/edit at the end of the show, run Chris and then finish it.
Koz
Yeah that’s a good description of a HUGE dynamic range.
The compressor is installed. Not too sure about the Compress Ratio units.
Does 0.5 mean 2:1 compression?
Now I see there’s a load of 2.1.3 plugins disabled. I don’t think those exist on the HD anymore.
Should we talk about them here or start another topic?
I’m using real-time compression in VLC and it works great, but it creates a little clipping.
Here are the settings I’m using for streaming audio.
And set Ratio between 4.0 and 6.0:1 depending on how LOW some parts are.
-Ed
The compressor is installed. Not too sure about the Compress Ratio units.
Does 0.5 mean 2:1 compression?
Not a clue. I presented the problem to the forum along with samples of the work and someone posted those settings. They worked.
Chris is intended to work by itself. It’s a stand-alone compressor.
You will also notice Chris will push the overall volume up. I don’t know anybody who complains about that.
This is a before and two afters: 0.5 and 0.77.
Note the theme song at the left more than doubled but the higher vocal peaks only went up a bit.
Koz