Parallel Compression Explained

Discussion in 'Tracking / Mixing / Editing' started by audiokid, Nov 2, 2011.

  1. audiokid

    audiokid Staff

    I'm demoing an A-Design HM2 Nail this month. One of the things it does OTB very well is Parallel Compression. Here is a bit on it from Ronan
    While searching for more information on this, I found a video from MikeChav explaining how he does this by duplicating a track and then compressing it. He then tucks the compressed track underneath the original.
    Any else have more on this, please chime in.

  2. BobRogers

    BobRogers Well-Known Member

    I don't use this technique for drum compression, but I think the concept is basically the same as using a reverb bus. On the reverb bus you have a completely wet sound, so it's easy to hear the characteristics of the sound. The sound itself is too wet, but it sounds right added back to the mix in small doses.
  3. audiokid

    audiokid Staff

    Good comparison Bob!

    Compression> HP /LPF/ Shape the thwack to blend > reverb bus.

    I've never tried Parallel Compression with vocals. anyone?
  4. RemyRAD

    RemyRAD Guest

    I thought this is a technique that most everybody had tried at some point? I've used parallel processing with all sorts of signal sources. For instance, either during tracking or during Mixdown I'll frequently take a vocalist assign them to 2 output buses to the multitrack. One bus goes direct, the second goes into a limiter/compressor and is printed on an adjacent track. Then these 2 tracks on Mixdown can be mixed together in varying amounts.

    When only one track has been cut, one can take the output of the multitrack machine and plug that track (whether software or hardware) into a Patchable MULT. Wish to give me 1 in with 3 passive identical outputs. One goes back into the console, directly and the other goes into your limiter of choice which then gets patched into another console input. The 2 different signals are then mixed together to taste.

    Sometimes I may equalize the 2 tracks slightly differently from each other? For instance, I may include a little extra presence boost on that compressed track. This can add an element of dynamic based equalization. Now I'm not talking about side chaining here. That too can be done during parallel processing. And in fact this can be a nicer way to create your own De-Essing. So if you sidechain 2000-7000 Hz, boosting with an equalizer, you can have better control over the sibilance without it getting too squashed. Reverse the phase, high and low pass filter and you will have a dynamic presence equalizer and keep things from getting too squawky.

    That was only on individual tracks. When you are mastering, parallel processing with minute amounts of delay can make a mix sound bigger than life. But there are so many other techniques one can employ. Like center image downward expansion. Broader sounding stereo imaging. Central centered Mono heaping of the stereo field. It's always fun stuff.

    None of this phases me unless I want it to
    Mx. Remy Ann David
  5. chavernac

    chavernac Active Member

    My 2 cents,
    It is pretty easy to use on drums.
    It can be subtle or "less" subtle.
    If you need more punch on your drums, compress the hell out of it with an open attack and tuck the new signal under the original sound.
    Id you need more "boyancy", more vibe, more room, use a short release and tuck in under.
  6. soapfloats

    soapfloats Well-Known Member

    In one form or another, this is a technique I use often.

    Compression, Reverb, or any effects.
    I don't often use it on individual tracks, but will use it w/ group buses often.

    Ex: 8 drum channels > Drum Bus > both ST bus and "Drum Compression" bus that also goes to ST bus
    Or: Vocal track(s) >Vocal Bus > ST bus + Vox Verb

    And so on....

    I do find it useful on single mic/track sources like a vocal or bass DI.

    In general, I find it is a nice technique for balancing any two elements of a source.

    And I'm really interested in trying Remy's approach to a stereo track/mix...
  7. audiokid

    audiokid Staff

    Parallel Compression where

    Thanks everyone, I think I have a good handle on this now. Parallel Compression sounds like its idea during the sub mix for low end punch or where a final mix could be a bit to top heavy needing some low end lift. Great for helping balance or pushing the bottom in dance music, yes? It also sounds like small doses are the way to go.
  8. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

    I found it useful on slap bass that was too peaky but didn't respond well to the conventional of compression and limiting I tried. The "body" of the notes was just overwhelmed by the pops and nothing I tried sounded okay. By copying the track and limiting the heck out of it to kill the peaks then mixing that track back in, I was able to fatten up the sound without killing the dynamic feel.
  9. Red Mastering

    Red Mastering Active Member

    0:40 sec in vid he mentioned EQ - I think it's a bad idea to do parallel EQ,
    as it will do mess with phase,
    correctly me if I'm wrong...
  10. niclaus

    niclaus Active Member

    What would you consider "minute amount of delay"??

  11. JohnTodd

    JohnTodd Well-Known Member

    I use it on drums and vocals.

    My drum setup is simple: I split the track into 2 copies and run one through a maximizer set to really throttle it. Mix as desired.

    But my vocal setup is based up "The Exciting Compressor" idea. My second track is run through a Waves L3-Multimaximizer set to really throttle it while subtracting the bass and mid-range. It basically returns a squashed treble signal. Mixing it back in allows my voice to be heard on the notes that drop down softly, or in other words, I can sing more expressively without getting lost in the mix. I've been getting great results on lead vocals this way and this whole scheme is set up permanently in my "studio template" I start each new project with in Cubase.
  12. RemyRAD

    RemyRAD Guest

    Well by minute's amount of delay, I'm generally referring to only a couple of milliseconds which can thicken the sound before it starts to sound like phase cancellation. And even less than that which can be accomplished down to the sample within software. And the length of delays is largely dependent upon how it sounds to you. Sometimes some high pass filtering on one of the pair of tracks and/or even phase inversion. Whatever it takes to create a sound you want.

    Another cool thing to try on the parallel processing is to invert the phases of one of the pairs of tracks. This will cause all sorts dynamically influenced strange dynamics. It's one of the ways of creating upward expansion. This method can help to undo over zealous compression & limiting without the need for a DBX thingy or nothin'. Besides, this way you get a better way to set thresholds where you want things to start happening. We're all just Kooky glorified electronic cooks that occasionally need to fix an otherwise botched recipe & cooking effort. So I also do a lot of restoration and recovery along with transfer to digital work out there I can get. Yeah, even though this cassette recording of little dead grandma playing the piano recorded upon the AVC (Automatic volume control) $20 Chinese battery-operated mono cassette gizmo, sitting on the coffee table with the air conditioning running. Being in the commercial recording studio business is not all rock 'n roll and cookies.

    I think I'll have another NUTTER BUTTER PEANUT BUTTER COOKIE?
    Mx. Remy Ann David
  13. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

    Two milliseconds will cause cancellations at 4kHz and above, so I'd be a bit hesitant to do that. The missing ingredient in that recipe is relative levels. When there is a difference in levels the cancellation is reduced. Same holds true for the phase problems that eq could cause.
  14. niclaus

    niclaus Active Member

    I agree but I Will still Give it a try and see what happens!!!

    Thanks for the recipes.
  15. RemyRAD

    RemyRAD Guest

    Sure, cancellation at 4 kHz can occur. So invert phase and the opposite will occur but other frequencies will cancel. Hence, perhaps a need for high pass filtering to protect the low-end from cancellation. I do a lot of time delay & phase manipulation techniques quite frequently. I do a lot of restoration, recovery and have been encouraged to go into forensic audio. Unfortunately I have little desire for forensics albeit quite fascinating. I was actually invited at one point to work on recovery of a black box voice recorder from a plane crash. It was fascinating but even more repugnant to me than doing TV news & politics shows. I mean you're hearing people who died. So if I don't want to record death metal, why would I want to hear a blackbox recording unless it's made by Joe Co.?

    They're small so get 2
    Mx. Remy Ann David
  16. Red Mastering

    Red Mastering Active Member

    you made my day!, and it was gloomy here in London,
    rainy day...thanks:)

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