Audiobook editing Hints and Tips

Is this the format and settings to follow and the sequence to follow ?
I found these at Audacity Hints and Tricks - KozCo

AudioBook Processing Tool Notes (Audacity 2.1.0)

LF Rolloff (rumble filter)
– Select the whole clip or show by clicking just above MUTE.
– Effect > Equalization: LF Rolloff for speech, about 5000 Length > OK

Noise Reduction
– Drag-select Room Tone, silence or the flat area between spoken phrases.
– Effect > Noise Reduction: Profile
– Select the whole clip or show by clicking just above MUTE.
– Effect > Noise Reduction: Settings 6, 6, 6 > OK

– Effect > Amplify: New Peak 0.0 > OK.
– Effect > Limiter: Limit -6, Hold 10 > OK.

Audio Compressor
– Select the whole clip or show by clicking just above MUTE.
– Effect > Normalize: [X]Remove DC, [X]Normalize to -3.5 > OK
– Effect > Compressor: Thresh -20, Floor -40, Ratio 2:1, Attack 0.2, Release 1.0, > OK
– Effect > Normalize: [X]Remove DC, [X]Normalize to -3.5 > OK

Thank you Koz

That was then.

Forever we were struggling with tools that could only set two of the three ACX AudioBook standards, Peak and Noise, but not RMS (loudness). And then Steve wrote one.

So the process is much shorter now (although it doesn’t seem like it from the step-by-step). Record in a good, quiet room, Export a safety WAV, Set loudness and apply the peak limiter. Run ACX-Check. If you did a good job of recording your voice, you’re done—out the door. If you miss it by a little, you can use the other two tools. But if you really recorded trash, you’ll be recording it again better.

You may want to reverse Noise Reduction and LF-Rolloff. You can’t hear gentle noise reduction, but you can hear LF-Rolloff working. Once you start using LF-Rolloff, you should keep using it through the whole show for consistency.

Limiter is built-in, but you have to download and install the other two. SetRMS is as close as you can get to actual computer programming. It’s an XML program you have to copy and paste as it says in the instructions. In general, you use it once, it “sticks,” and you don’t have to paste it again.

If you make it to the last two tools, rolloff and noise, record a test and post it on the forum.

We can tell you what’s wrong with your work.


I remember now.

AudioBook Processing Tool Notes (Audacity 2.1.0)

That’s not a how-to. That’s just a list of tools I posted because I could never remember the settings. You should never need all of them. I’ll change that note. Also, I wrote that before I wrote the Mastering thing and before Steve wrote SetRMS (which you note isn’t listed).


Thanks Koz for the response.

Is the Audio Compressor Step normalize - compressor - normalize skipped or unimportant?
I don’t ACX but are these hints and tips for “cutting spots” (old radio lingo)? I might take a crack at that. I don’t have the patience for whole book reading.


I updated the Audacity notes.

The mastering page is the whole thing.

I don’t think compressor is mentioned at all in there.

Many of the older tools and fancy applications went away when SetRMS was written. We always had to get the proper voice volume by working around the barn with the other tools and sometimes multiple passes. Now, it’s all in one step. Well, two, actually. SetRMS will shove your loudness around so the AudioBook loudness specification is met. This is very likely to leave some of your expressive peaks and vocal ticks too loud for either audiobook or even distortion specifications (clipping). While the show is inside Audacity, it’s not subject to clipping, so run Effect > Limiter at those settings to bring everything into compliance.

Please note nowhere is noise mentioned. This whole dance only works if you have a reasonably quiet studio and microphone. If you don’t, then we just left simple processing and mastering in the dust.

And just to make this as complicated as possible, if you’re reading for broadcast, then it’s up to you to meet their sound file specifications. ACX AudioBook just happens to be a convenient, well-documented standard. I can’t believe anybody would turn that down, but it’s not up to me.

There was a poster who was preparing a broadcast radio show from home in Maine. His delivery was finished MP3 played in one of their studios. He was cutting the show at home with MP3 music and after broadcast, the station tried to make an MP3 podcast. Too many MP3s. The podcast turned to audio garbage. We told him they had to let him deliver in something higher quality.

That’s the kind of wacky problems you can have when working from home.

I was the audio dude for a broadcast radio program partially shot in Los Angeles. They provided me with a list of requirements and I went down the list and satisfied them all. Since I was recording in a soundproof conference room, our segment went straight to air with no corrections.