Replicating Audacity's "soft limit" function

Hi all,

So in my professional life I master audio books, and lately a new client is demanding I use Adobe Audition CC. I suppose it’s because they want to do export direct to Pro Tools for multi-voice projects.

I love the tool inside Audacity that allows me to soft limit to, say, -2.9dB. I’ve tried for weeks without success to replicate this function in Audition. The new version of Audition has a hard limit function, but it keeps clipping my audio. Poking around the Internet, I see lots of discussion that says a “soft limit” can be replicated using a compressor, yadda yadda, yadda, but I wonder if that’s true because a compressor brings up the background noise where the soft limit doesn’t. :confused: :confused:

So, can anyone explain to me in rice and beans what Audacity’s “soft limit” does, and how I can replicate it using standard steps in another software? I’m still using Audacity for other projects, I promise.

Would your client mind if you open the file in Audacity to run the limiter? Will your client know? Does the client get to say what tools you use?

see lots of discussion that says a “soft limit” can be replicated using a compressor,

That’s sort-of true. Limiting is a kind of fast compression. But, it’s tricky to get any two effects to behave exactly the same… You probably can’t get the same-exact result with the Audacity and the Audition compressors.

There are lots of 3rd-party VST plug-ins, some free and some you have to pay for. You should be able to find something that works with Audition and does what you want. Compression and limiting are some of the most common effects (along with EQ and reverb).

a compressor brings up the background noise where the soft limit doesn’t.

It’s (usually) not the compression, it’s the make-up gain. The same thing will happen if you apply make-up gain with limiting.

Hard & soft knees …

We had Leveler that used a simple “knee” and would progressively squash waveform peaks as they got higher and higher. The newer “dynamic” Limiter worked so much better that Leveler was consigned to the bin behind the camper until a bunch of us rose up as one, dragged it back inside and insisted it be reinstated. The reason for this was its distortion. There is no better way to simulate taxi, 2-way radio and air traffic voices than multiple passes through stiff Leveler.

"Roger, Lufthansa 26, clear for departure Two Four Right. Good day."

This effect works so well because 2-way radios use a very similar technique for voice processing. It was a marriage made in heaven. Leveler is now available under Effect > Distortion.

Effect > Limiter has very little apparent distortion because it’s a look-ahead processor that very rapidly turns the volume up and down to achieve the effect. It’s not just whacking off peaks. That’s why it has dynamic adjustments such as the “hold” setting.


The “Limiter” effect is described here:
“Soft Limit” and “Hard Limit” produce the least amount of crunchy distortion.

And not to take the tools in a vacuum, AudioBook Mastering 4 combines three tools into a suite.

Effect > Equalization runs a rumble filter to eliminate room and microphone error rumble.
Effect > RMS Normalize to set overall RMS (Loudness).
Effect > Limiter to clear up any peak errors.

If you recorded in a quiet room, you’re done.

The suite is applicable to many different recording techniques and can’t be heard working in normal operation.