Settings for VLC dynamic range compression

Kept Googling for this, so finally figured I should note it down on my own blog. The dynamic range compressor in VLC is a very handy tool I discovered recently. You can use it to even out movies which have both very quiet and very loud scenes so you can hear what people say and not damage your ears when the action scenes kick in.

You find the thing in VLC under Tools, Effects and Filters, Audio Effects, Compressor. Or simply just press Ctrl+E.

Update: To make the Compressor settings persist through VLC restarts, select the Write changes to config option on the Compressor setting tab.

Update: To make the Compressor on by default when you launch VLC, go to Preferences, All, Audio and Filters, and check the Dynamic range compressor box.

Following are some good initial settings you can use. Remember to hit the Enable dynamic range compressor checkbox, or it won’t do much good πŸ˜‰

RMS/peak

0.0

If threshold should apply to peaks (machine-like) or RMS values (human-ear-like)
Attack

50 ms

How quick to react
Release

300 ms

How slow to release
Threshold

-20.0 dB

When to react
Ratio

20.0:1

How much to compress levels above the treshold
Knee radius

1.0 dB

How soft the compressor should kick in. Zero will apply ratio immediately when level hits threshold. Higher values leads to softer compression closer to the threshold.
Makeup gain

12.0 dB

Fixed audio boost

As you see, I’m not quite sure what all these does, but these settings are a good start which usually gives a good result in my experience. I usually only adjust the makeup gain and leave the others as specified above.

If you know exactly what they do, don’t hesitate to leave a comment and explain it to me cause I’d love to know!

Source: ariandy1.wordpress.com

  • Helholtz

    Well, this seems rather old, but I was looking for a way to toggle the compressor on in Mac VLC, as I could only adjust settings. It helped me, as the command was Cmd + Shift + E, similar to the one provided here for Windows’.
    Also, as you suggested someone explaining the parameters you don’t know, I’ll try to be brief:
    The compressor basically drops the level of the signal whenever such level is above the THRESHOLD level, by a fixed RATIO (ex. 4:1 means that if the level of the signal is above the threshold it will be divided by four, and such). Then, it boosts all the signal by a fixed amount (the MAKEUP GAIN). The RMS/Peak parameter controls whether this threshold applies to peaks (more machine-like) or to RMS values (more human-ear-like). The KNEE RADIUS determines how softly the compressor kicks in. When it’s set to zero, it means it will apply the ratio instantly as soon as the level is above the threshold. With higher values, the compression will be softer the closer the level is to the threshold.
    Anyway, both of this parameters (RMS/Peak and knee radius) are very subtle and make little difference to untrained ears.

    Also, a good rule of the thumb in order to avoid destroying the dynamics is to keep the ratio below 10.0:1 (I like 4.0:1, but it depends on the movie). And to avoid clipping, the make up gain shouldn’t be too high (the idea is to compensate the compression, so it should be more as the ratio goes up, and less as the threshold goes up). I wouldn’t recommend using the makeup gain to boost the signal, as there are other instances in the audio chain where you can do so.

    • Thanks! Tried updating the post with the explanations. What kind of values do you usually use for the other settings? And what would you recommend for boosting the signal? I usually use this for movies which tend to have a lot lower volume than other things on my computer (YouTube, music, games, etc)

    • Don Joe

      So at which end is the RMS option, 0.0 or 1.0?

      • Don Joe

        I guess if I interpret “RMS/peak” as a ratio it means 1.0 is full-RMS and 0.0 full-peak.

  • christopherjacques

    I live in a super tiny apartment where I have to keep things quietish (I hate it) so this compression worked so well. I had to make my settings more extreme, but regardless, it’s awesome and works exactly as I’d hoped!!!

  • Rob McCathie

    I don’t see any point in using makeup gain, it’s simply amplification and we don’t want to needlessly add more instances of amplification than is required, the effect on quality can only be negative. We’ve already got the VLC volume, the system volume and your speaker’s/amplifier’s hardware volume to use, IMO you only want to have any makeup gain if you already have all existing volumes maxed and still want more.

    20:1 ratio seems fairly excessive. IMO that sort of ratio reduces the loud sounds in movies too far under the dialogue volume, making the compression very noticeable. Personally i use 8:1 (as normal default at least, maybe there was one or two movies where i tweaked it)

    Threshold is in my experience the main setting that often needs tweaking for different movies. My usual default is -25, but a movie where the dialogue is particularly low may require -30 (because what would usually be mid-level sounds still need to be compressed because of how high we have to put the volume just to hear the dialogue), and in some cases where the dialogue is a bit louder you need to come up to -20 or higher just so the compressor isn’t constantly in effect.

    my2cents

    • The Makeup Gain is to compensate for the reduction in volumes that can be caused by the other settings. Toggle the Compressor on and off to see if any Makeup Gain is required.

  • o Psaras

    Nice work. I always come back to your page every time I lose my VLC compressor settings. The only thing I change drastically is the Makeup Gain. Most of my devices need no more than 5dB of gain for the dialogues to sound the same with and without the compressor. I currently have it on 4dB for my 2.0 USB-powered speakers, but I set it even lower for some 2.1 and 5.1 I use.

    My current settings, for an apartment with medium to good sound proofness and 2.0 USB-powered speakers:
    RMS/peak: 0
    Attack: 30.2 ms
    Release: 300 ms
    Threshold: -22.6 dB
    Ration: 20.0:1
    Knee Radius: 1.0dB
    Makeup Gain: 4.0dB

    Thank you

    • Thanks for sharing! Especially the equalizer settings. I rarely use it, cause I don’t really know what to do with it πŸ˜› Not bothering neighbours is a great use though!

  • Jason

    This is EXACTLY what I was looking for. Apartment dweller with thin walls! tired of having to keep the keyboard close to react to action sequences. Thank you!

    Once I find settings that I like I’ll post!

    Great article!

  • GuccizBud

    A word on customizing these settings for yourself. The two key settings for bringing the volume of too-loud and too-soft passages in line with the rest of the movie are the *Threshold* and *Makeup gain* settings. *Threshold* is used to deal with the too-loud passages; *Makeup gain* deals with the too-soft ones. You can play around with the other five settings to get an idea of their effects, but on the whole their impact is minimal compared to *Threshold* and *Makeup gain* insofar as trying to normalize too-loud and too-soft sections.

    As such, the following is one way of proceedingβ€Š:


      
    1. Preset the followingβ€Š:
      
       ① RMS/peakβ€ƒβ€ƒβ€ƒβ€Šβ€Š:β€Š β€Šβ€Š0.0
       ⑑ Attack     :β€Š β€Šβ€Š50.0β€Šβ€Šms
       ⑒ Releaseβ€ƒβ€ƒβ€ƒβ€ƒβ€Š:β€Š β€Šβ€Š300.0β€Šβ€Šms
    β€ƒβ€‚β‡‰β€‚β€Šβ‘£ *Threshold*   β€Šβ€Šβ€Š:β€Š –.-β€Šβ€ŠdB
       ⑀ Ratio      β€Šβ€Š:β€Š β€Šβ€Š20.0β€Šβ€Š:β€Š1 β€Š(β€Šall the way upβ€Š)
       β‘₯ Knee radius   β€Š:β€Š β€Šβ€Š1.0β€Šβ€ŠdB
    β€ƒβ€‚β‡‰β€‚β€Šβ‘¦ *Makeup gain*  :β€Š –.-β€Šβ€ŠdB
      
      Note there are no values provided for β‘£ and ⑦ just yet, as their values will be determined by YOU according to
      the instructions in the steps below.
      
    2. Select a movie and set the overall volume in VLC to the level you would like it to be at when listening to itβ€Šβ€”β€Šwhich
      is to say, the level you would normally leave it at if there were no particularly soft or particularly loud passages in
      the movie.
      
    3. Find a LOUD passage in the movie and, without changing the overall volume set in the previous step, adjust β€Šβ‘£
      *Threshold*β€Š to a level which you feel is audibly comfortable, i.e. such that its perceived volume is more in line with
      the bulk of the movie rather than being noticeably louder.
      
    4. Now find a QUIET passage in the movie (β€Šsuch as a quiet dialogue sceneβ€Š) and, again without changing overall
      volume, adjustβ€Š ⑦ *Makeup gain*β€Š to a level which you feel is audibly comfortable, i.e. such that its perceived
      volume is more in line with the rest of the movie rather than being noticeably softer.

    That’s it. Give it a try, see if it does the job for you. Don’t forget to put a checkmark in the “Write changes to config” box to make the settings always apply.

    • swifterik

      Thanks so much. It’s literally these two settings that take the most effect. It still doesn’t feel like good ol’ windows volume equalization, but it finally sounds like the compressor is doing something useful.

  • n i e l s

    I had to use a bit stronger settings than what you’re listing, to get a handle on Hollywood’s dynamic-range extremism:
    Threshhold -30.0 dB (this is really what takes down the extreme noise to near conversation level – a sort of night time setting.
    Ratio 20:1 (this is the same as yours and works well)
    Knee Radius: 4dB (this preserves sound quality somewhat better than a 1dB setting)
    Makeup Gain: 16 dB (this is not completely arbitrary, as a higher setting will improve signal quality along your signal chain, by preventing signal strength from becoming too low)