Calculating Compressor Attack and Release Time?

Discussion in 'Recording Gear and Equipment [BG]' started by 3alfa3, Mar 3, 2018.

  1. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    If I generate audio track in Software (Cool Edit Pro for example :) ) and that Track contains 5 Second sine tone following with 10 Seconds of Silence (and multiply this to get 1-5 Minute total duration), can i visually determine attack and release times (selecting peak for attack and decay for Release and take measurement from Time Bar) after i play this track thru Compressor Pedal and record compressed File to take measurements?

    I would like to see if marks on my Compressor Pedal for Attack and Release are in the ballpark, because, i have Feeling they are way off (Attack Time seems to be much longer than markings).

    Is it possible to get a meaningful result this way?
     
    Last edited: Mar 3, 2018
  2. J Posega

    J Posega Cat Dad and Dingwall Enthusiast Supporting Member

    Jul 16, 2005
    Los Angeles, CA
    I don’t know, but my recommendation is ignore the markings and use your ears.
     
  3. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    I just did a test:
    First picture is attack time, and second is release time. Third picture is Chart I found on Internet which explain attack and release times.
    I set Attack on Compressor to 0,20ms and Release to 100ms.
    Release time is OK: 113ms measured.
    But Attack time is 70ms instead of 0,2ms - 350 Times greater!!!

    Did I correctly measure the attack time (look at the first Picture)?

    attack.PNG release.PNG 600px-Audio_Compression_Attack_and_Release-2.svg.png
     
  4. saabfender

    saabfender Inactive

    Jan 10, 2018
    Indianapolis
    I'm sorry but no. This is no way to adjust your compressor. That's not how they work. As has been said, you adjust them by ear. I've used rackmount compressors with five parameter adjustment for forever. I don't think I've ever used the markings to set it up.
     
  5. toowrongfoo

    toowrongfoo

    Nov 25, 2017
    As simplistic as that sounds, it's true. If you don't know what a good bass setting is, make sure you start with the most gentle settings, season to taste. Sometime in VST's I get lucky and find one of those "whoa" settings in the presets.
     
  6. toowrongfoo

    toowrongfoo

    Nov 25, 2017
    Also, keep in mind, not all compressors are created equal. I've got more than I should and they are all different. Famous bass comps are the DBX160, the LA-2A and maybe even a Distressor. There are WAY more, but that is a starting off point.
     
  7. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    I just wanted to check if markings on pedal are in ballpark. I do have a prefered setting for my needs most of the time (see picture) :)
    If my Method is OK, Ratio, attenuation in db and release time are OK. But Attack Time is debatable.

    This is my setting (attenuation is between -3 and -6db most of the time). If i slow Attack time just little beyond this, transients are unusable long. In Auto mode, they are less accentuated than in Manual mode with Attack Time as fast as possible (0,15mS if marking is correct for manual mode).



    ....and i DO like Transients to be heard (thats why i use Daddario Prosteels - i like bright sound), but they last too long if i slower attack just a liitle beyond this.

    Sorry for my bad English :)

    IMG_6532.JPG
     
    Last edited: Mar 4, 2018
  8. saabfender

    saabfender Inactive

    Jan 10, 2018
    Indianapolis
    That looks wrong. Release should not be that fast. The GR lights are your friend; watch them.

    Here's a short video. The guy's talking perfect sense and it's about a minute and a half. The narration is a little hard to hear but listen closely.

     
    Zooberwerx likes this.
  9. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    Geez, just use your ears not your eyes. The only advantage of numbers (either arbitrary or actual times) is for consistency when setting the compressor up. When using software...not just compression, but also EQ, distortion and other FX...I like to close my eyes and listen carefully while I adjust (I use a knobby controller not the mouse).

    If you want the compression to be more obvious (squashed): short attack, long release

    If you want it more transparent: long attack, short release.

    What to listen for:

    Does the attack of the note sound unnatural?
    Does the sound "pump" in volume?
    If compressing while playing, does it feel like you are fighting the compressor to express dynamics?
     
  10. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    I do, of course. But this topic is not about that. It is about getting data and compare it with markings on Pedal. ;)
     
  11. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    Thanks for the link.....


    About Release time.....
    i like it as fast as possible (without distortion, which i am not getting with this pedal no matter what) so next Note is "new Note" - to preserve Transients. I play fast - up to 8-10 strokes per second sometimes. Slower release times are too slow for that in regard of preserving Transients. For 10 strokes per second, i need 100ms release time, or Compressor will not release before next Note. And that is just Numbers -i do it by ear, and find that 100ms is OK for me. Slower than this, I am "squashed" most of the time. I did experimented with longer release times, but always come back to 100ms (100ms is minimum for this pedal, not 150 as printed, as explained from Robert Keeley himself and my measurements confirmed that)
     
    saabfender likes this.
  12. saabfender

    saabfender Inactive

    Jan 10, 2018
    Indianapolis
    So why are you using a compressor at all? Is there a law in Croatia we are not aware of? The function of a compressor is to shave off transients, where most of the high-frequency content lives. It's what they do.
     
  13. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    There are some ridiculous laws in Croatia, but Compressor is excluded from that (so far) :D

    The function of compressor is not to shave off transients (but it can be used that way). It is for controling dynamics.
    Transinets can be shaved off OR can be emphasized.
    I like them to be emphasized along with moderate dynamic control overall.
    Finding attack time to do that without pumping and swelling is what im after.
     
  14. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    Btw, can we put music, compression etc aside. Topic was created to determine if that was right way to calculate attack time. Math, not Music ;)
     
  15. saabfender

    saabfender Inactive

    Jan 10, 2018
    Indianapolis
    I misspoke. That's not necessarily a compressor's function but it is their mechanism by which they control dynamics. It is literally how they work: minimizing the transient peaks so the rest can be louder, the whole thing using less dynamic range. It's curious to me why someone with no experience with compressors is arguing this point with someone who has a couple decades of experience live and in the studio using compressors.

    EDIT: The math is irrelevant.
     
  16. 3alfa3

    3alfa3

    Mar 14, 2016
    Zagreb, Croatia
    That would be true if attack time is 0. But its not. Attack time is all about Transients and how long Compressor wait before doing anything.
    And Math IS relevant in this Topic, because, Question in first post was just that - how to measure, not how to feel or hear.
     
  17. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    Different compressors have different attack/release behavior so looking at numbers on the screen and transferring to pedals is not necessarily going to get you close, esp. if the pedal is not marked in units of time. Good luck.
     
  18. Eliminating or reducing the attack on bass takes away from the natural sound of the instrument; it's the attack that defines the note and is important for timing. Generally you want to preserve the attack, but compress the sustained portion of the note, which does two things: It allows the weaker notes to pass through without any compression, but stronger notes are compressed to match the level of the weaker notes. The makeup gain is then increased to bring everything back up to a usable volume level. This provides and even punchy sound.

    It is also possible to overcompress by using too high a compression ratio. This sucks the life out of the bass line because it no longer has any dynamics, and not allowing the bassist to have any control over the dynamics. An example of this sound would be a cheesy, cheap keyboard bass.

    The release time is important too, as another member pointed out; if the release time is too long, it will still be compressing when the subsequent note occurs, killing the attack.
     
    petrus61 likes this.
  19. Basically keep turning knobs until your head explodes and remember, while attack and release times are important, the times marked on the knob are arbitrary and meaningless...

    That’s what I’m getting from this thread.
     
    saabfender likes this.
  20. You got it. The indications on the controls are just to give you and idea of where you are at with the settings, but there isn't any strict formula for adjusting the parameters.
     
    saabfender likes this.