Compressing the input signal


Any suggestions? You could say ‘Ardour2 Manual’ but what benefit do you truly get from that honestly?

You could say 'Ardour2 Manual' but what benefit do you truly get from that honestly?
Seriously? You're questioning what benefit there is in having menu options that actually describe the thing they do?

You’re assuming that this would mean anything to most people who read it. Hang out on IRC for a long time, and you will be disabused of this notion. We probably just need to remove the link entirely, which is a shame because it was a nice effort at a tutorial-ish manual.

@stratojaune: Unfortunately only one of my mixers, a Presonus, has the option of post-compressor/pre-fader on the direct channel outputs. My other mixer, Soundcraft Si Expresssion, always sends the direct out before the compressor. Guess I’ll be learning more about busses as paul suggested in his post to this thread on Thu, 2015-04-09 15:15.


Sadly that will not help you really. If you are doing live recordings and using the compressor to prevent clipping, using a bus in Ardour (After the AD stage) will not help prevent clipping at all, it will just compress it. You need to compress before the clipping happens.

Really the best option is to set gain structure appropriately. Obviously you will always get oddball peaks in live performances, but is there a reason your gain structure live is set in a way that peaking is a serious problem? If you are finding you need more volume, can you turn up the gain on your amps/speakers instead to allow you to lower the gain added by the console/preamps?


Actually it is worth noting that in both the Presonus and the Soundcraft the compressor is still after the AD stage, so even those won’t help you much. You have to do it between the preamp and the AD (Analog to Digital converter). In some consoles the analog insert points are exactly there for this reason, they are before the AD stage but after the preamp, so that might give you an option.



If you haven’t already, try out the meterbridge window in Ardour (Might be just the RCs/nightlies that have it). It will change your workflow when doing gigs like that, VERY high resolution when made full screen, and you can arm recordings from it as well.

Also don’t forget that with 24 bit conversions(Well realistically 20-21 bit), you can set your gain pretty conservative and not have to worry about noise floor, this applies to both your recordings and live as well.


I have plenty of headroom with amps and speakers and don’t overload the analog preamps. It’s more about what I have time to pay attention to. What looks like a good recording level during a sound check (if I’m lucky enough to get one) may be obliterated during the performance.

On the other hand, today I recorded a country rock band doing a rehearsal and it was very predictable. The mixer window in Ardour was a nice way to monitor pre-fader channel levels and adjust the preamp gain on my mixer. It had more resolution than the limited number of LEDs on the mixer and the peak-hold marks were nice. Will export some samples tomorrow.

Another solution to the specific problem of a source with mad dynamic range is to record the same source simultaneously on two tracks, one 10-20dB higher than the other. Some professional tape recorders used to do this. Afterwards you choose which to use or switch judiciously between the two during editing/mixing.
That way no compressor is needed.

True, but this is a problem when dealing with live recording, which it sounds like mashworth is. For one thing it requires two preamps on the console, and requires you to monitor the input levels of two different channels instead of one. Generally it just isn’t to good an idea unless you have someone dedicated to doing that, then a passive split on the XLR, and careful phantom power management is needed. It just generally isn’t worth the hassle compared to getting the gain right on the single channel to start with.


Who has lots of experience doing tracking of live performances;)

Compressor plugin settings? When I export a normalized file from the Ardour export dialog a sharp peak in amplitude will control the average level final output mix. This has been a problem with one particular recording that has a very dynamic drummer. I’m looking for suggestions on how to set a compressor plugin to mitigate the problem. I want to avoid editing many tiny regions of the drum tracks individually.

Here is what I tried so far. I created a stereo drum buss and routed the drum channels to it selecting which ones I wanted to patch to the left and right inputs of the buss. I added a Calf stereo compressor plugin to the drum buss post fader. I adjusted the compressor to a relatively fast attack, high ratio, peak detection and sharp knee. This triggered a meter display that indicated compression. It was helpful to view the moving dot in the compressor display and the peak hold meter on the Master fader bus to see how this affected my final output. Here are a few questions.

  1. Will the compressor plugin still be applied to the drum channels if I add it to the drum buss pre-fader? That will allow me to raise and lower the drum buss volume without resetting the compressor input level.
  2. What attack and release values are effective without sounding obnoxious.
  3. What ratio?
  4. How sharp a knee?
  5. Other ways to deal with this problem?

The drums also bleed into vocal and horn mics but I don’t want to use the same compressor settings on them.

  1. Yes
  2. Depends on the material. Snare and Kick I tend to do fast attack and fast release (Pop/Rock music). Toms as well, though their timing may drift a bit.
  3. Whatever is appropriate, this and threshold depend on the recording/drummer in question.
  4. See #3, but chances are a sharper knee will be fine for this and more likely what you want.
  5. A brickwall limiter is often used as one of the last plugins on the master track to help with this, you could also play with one on the drum track, just be careful about overdoing it.

Of course the standard disclaimer of less is more when dealing with compression applies.