Apply dynamic range compression on a region?

In Audacity, I usually deal with speeches and before I finally “master” them, I “amplify” and then apply a little “compression” so the quiet parts become a little louder too.

In Ardour, I figured that the “amplify” option is actually “Boost Gain Region”. OK, alright. What about “compression” ?

How do I apply the Dynamic compression on a region? Is there such a feature?


Add a compressor to the channel that the speech is on.

If you only need in on part of the timeline of that track, utilize automation.


or bounce the region (with processing) it to the region list then bring it back into the track. ardour 3 will have a technique for doing this in a single step. (oh, and then disable the compressor plugin or remove it).

Ok, I will look into that… slowly I am “getting” about this non destructive editing.

By the way @Paul:

I just found your clone over the internet, his nick is AlienBOB…LOL
You guys look like a lot.

It seems to me the OP may need basic information about how to use plugins. It may be entirely non-obvious to someone coming from Audacity to Ardour, what those black rectangles above and below the fader are for.


OK guys, so I have learned how to add a compressor…

I added the “Calf compressor” and I immediately can tell by the sound it changed to a more boosted gain and compression.

But I want to figure how do I “see” the waveform or apply this modification onto the waveform, so that it can change visually… is there a way?

Also, when I export the region to audiofile, none of the changes go in…


If you export the whole mix (not just a region) to a stereo file, it will have all the compression and other processing you heard while playing it back.

Adding processing doesn’t change the audio in the region itself. It just inserts a processor in the path between one place and another, usually between the the track and the master bus. The processor runs while playing back, or when exporting the master bus, which is just like playing back but saving the result in a file instead of playing it in real time.

There are some actions in Ardour that actually save their results, like pitch shifting and time stretching. When you do that the result is stored in a newly created region - but the old region is still there with its data unchanged. Those actions are done by context-clicking the region, not by inserting a processor into the signal path, so they are quite different.

I figured that if I select menu context and choose FREEZE, it will apply the effect to the audio.
However, I am getting a segfault here. If I unfreeze, it crashes (F18).
But when I re-start ardour, then the waveform appears altered.

Is there a way to refresh the waveform visualization?

@BourneShell: what version of Ardour and where did you get it from?

2.8.16 on Fedora 18 released just today. I got it from the official repos.
I would bet this is a Fedora bug for sure…

By the way, which distro do you develop on Paul ?

I was actually thinking of moving to Slackware for good…

the OP may need basic information about how to use plugins

Also to understand the difference in approach between destructive and non-destructive editing.

ALIEN Bob… it’s all beginning to make sense.

Kelleydv -
Thanks for your reply. I suspected that we might have been working from different configs and that is indeed the case.
I see, from my posting on Mantis, that there is an issue with bounce w/ processing and so I’m trying various work-arounds,
such as prepping my tracks in A2 first. If A2 bounce w/ processing works then I might just fall back and use A2… too bad you
can’t just open up an A3 project with A2.

Very Best Regards,

OS X betas right now are far from stable, be it 4 or 5, and the OS X release will likely come after the Linux release as a result. It doesn’t really surprise me there is a difference between OS X and Linux in this regards though, sorry.


PBuryk: A3 can open all the A2 sessions that we have tested with so far (though with some loss of information/settings because there are deep changes in some aspects of the program). If you have a session that does not load, it should be reported to mantis.


He was saying it is to bad the other way (A2 opening A3 sessions) can’t happen:)


I just tested with Ubuntu 12.04 LTS and Ardour 2.8.12
The glitch does not occur. Freezes and unfreezes perfectly fine!

Going to install Slackware and compile from source to see if I have luck with 2.8.16

Installed all from SlackBuilds and compiled 2.8.14 from source. Freezing does not refresh the waveform and when you right-click the waveform right after, the app crashes. On all systems, this is the line dmesg dumps… Surely something went wrong, 2.8.12 does not have that issue as I tested.

[ 5908.697222] ardour-2.8.14[30659]: segfault at 268 ip 0000000000651db3 sp 00007fffa834d9e0 error 4 in ardour-2.8.14[400000+5a3000]

Make certain all your testing goes into Mantis.