Groove Pump Compression System

Monday, May 15th, 2006 | 2:27 pm and filed in Reason, peff, Combinator, Tutorials.


Over the weekend, I was up late, chatting with my friend, DJ Kage, and the subject of sidechain compression came up. Actually this was the third time it’s come up in the past 3 weeks, and something triggered the idea of how to create a rhythmic pumping compression side chain configuration. In a bit of a whirlwind on Sunday Morning, I put together a set of different beat pumping - over compression combinators designed for dance, trance, house, or any style of electronic music with a 4/4 beat.

With some hardware compressors, the attack time can be stretched out for a long duration, however with the MClass Compressor in Reason, you’re limited to about 100 milliseconds. This is fine for mastering, but it’s ineffective for this production technique of “pumping” a beat. Then it dawned on me: simply delay the sidechain signal using a DDL-1. This would allow for the extra time needed to successfully create the pumping effect.

At first, the configuration was comprised of a frequency dependent sidechain where a low pass filter is tuned to isolate the bass frequencies of a kick drum, then delayed by one step before returning to the Compressor sidechain input. Kage commented “Think Daft Punk!”, and so the combi’s were aptly named “Daft Pump”.

The Daft Pump is not 100% effective as a single patch, primarily because it is a frequency dependent compressor, and requires the end user to tweak the sidechain signal for optimum performance. This eventually led me down another path where a kick drum track was introduced into the sidechain from a ReDrum. This independent sidechain signal is optimized without requiring the user to tweak filter or limiter settings. Thus, the “Groove Pump” was born - a sort of keyed compressor/gating effect that’s controlled with it’s own sequencer.

The Groove Pump and Daft Pump basically have the same signal processing chain, the difference is the sidechain processing. On the Groove Pump, the Redrum kick track is delayed and processed with a MClass Maximizer, and then connected to a MClass Compressor sidechain input. The delayed sidechain signal ducks the signal passing through the Compressor a step (+ a bit more) late to induce the pumping effect.

The Groove Pump Compression System Refill contains 16 Groove Pump Combis and 16 Daft Pump Combis, and two example files that demonstrate the effect. These are effect combis so remember to set the Reason 3 browser to “Show All Effects” when attempting to load them.

Download the Groove Pump Compression System Refill (3Mb)

Groove Pump Parameters

Pump Offset controls the delay time in milliseconds of a second DDL-1. This allows for a slightly longer lag before the compression is applied to the passing signal.

Pump Intensity controls the intensity of the compression effect. Higher settings will increase the ducking effect and reduce the signal dramatically. .

Attack controls the compressor attack time to shape the rate of gain reduction. Short attack time will create a very sharp drop in levels, while higher attack times will set a gentle(r) sloping level reduction.

Release controls the compressor release time. This shapes the recovery time from dipping levels back up to normal levels. The minimum setting is 50 ms, and so a sharp release is not possible, but it allows for a longer recovery time - the time for the trough to rise back up to normal loudness.

Upbeat - Dwnbeat Switch adjusts the first sidechain delay stage between 1 step (Off) or 2 steps(On).

Knee Switch enables the Soft Knee feature on the MClass Compressor. This changes the pumping from a hard linear gain reduction (Off) to a gentler curved slope (On).

Peak Shaper Switch enables a second MClass Compressor to compensate for the heavy over-compression induced in the first stage of the effect.

Impact Switch enables a MClass Maximizer set as a peak limiter for the effect chain. The soft clip feature induces the subtle distortion and adds more of an impact to the passing signal.

You can also try making modifications to the patch by changing the kick drum pattern. Keep in mind the kicks are delayed so they should be programmed at the normal intervals and not at the position where you want the pumping to occur.

Another modification is to bypass the first DDL-1 and increase the adjustment range of the Pump Offset (Rotary 1) to 500 to 700 milliseconds. This provides a way of getting precise pumping points between beats.

Modifying the Daft Pump Sidechain Signal

For the adventurous, using the Daft Pump Combis can be an interesting way to learn about sidechain compression. The first step to working with this effect is to tune the filters so that the sidechain efficiently keys in on the kick drum signal.

The following project uses a Hip-Hop loop with several layered bass frequencies. The objective is to filter and EQ the sidechain in an effort to isolate just the kick. The pumping effect is then keyed to the kick. The following project explains the process in PTR-3 fashion. Before and After RNS files are also provided as well.

Download the “DaftPumpTweak.rns” File

1. Open the File and Play the loop to hear the initial state. What you’re hearing is basically the loop with too much compression. The sub bass is massive, and the sidechain is keying in on all of the bass causing the MClass Compressor to stay closed all of the time.

2. Click on the “Show Devices” button of the Daft Pump Combi to expand the rack.

3. On the MClass Compressor labelled “Main Pumper” enable the “Solo Sidechain button”. If it’s not still running, play the song to audition the massive bass on the sidechain signal. You can hear the main sub-bass, and the occasional thump from the kick. The aim is to isolate that thump and filter out the sub-bass.

4. Increase the Filter Cutoff Frequency on “Filter 1″ to about 48. This opens the filter a bit so that more of the kick thump passes.

5. Select the ECF-42 and insert an MClass Equalizer. Continue to play the loop as you make the following adjustments.

6. On the Equalizer, enable the Low Cut (HPF) and Low Shelf. Decrease the Lo Shelf Gain to -18.3dB, Frequency to 271.2 Hz, and Q to 2.

7. On the Equalizer, enable the Parametric 1 stage. Set the Param 1 Q to 32, Gain to 18.3dB, and Freq to 89.0 Hz.

8. On the Equalizer, enable the Parametric 2 stage. Set the Param Gain to -18.3dB and Frequency to 47.7 Hz.

9. Select the Equalizer and create an ECF-42 Envelope Controlled Filter. This should be inserted after the EQ to filter off some of the snare hits. Set the EQ mode to LP24, and frequency to 44.

10. On the MClass Maximizer labelled “Sidechain Limiter” adjust the Output gain to 10.7dB, then adjust the Input Gain to 10.7dB. This provides a suitable amount of make up gain for the filtered down sidechain signal of the isolated kick.

11. On the Compressor labelled “Main Pumper” Disable the Solo Sidechain button, and play the song to hear the compression pump the signal behind each kick.

12. Save the file for future reference :-)

Download the finished “DaftpumpTweaked.rns” file

13 Responses to “Groove Pump Compression System”

  1. Flandersh Says:

    Great lovely work man! Have worked on a bassline that have a really cool ducking effect myself…

  2. Mark Says:

    Fantastic. Just what I was trying to do !!

  3. ReasonFan Says:

    Wow thats awesome!!! good job Kurt.

  4. maustaste Says:

    Wow! Amazing ! Great ! & Nice to use ……….
    Very intressting. i ve done a new refill called ethnotica and use it experimently with yours . what can i say ? only wow!


  5. Ant Says:

    ya! I bought your book some time ago. It’s great to see you continuing the teachings and experimentation via your site. Kinda an ongoing lesson :)

    I’ve only used the sidechain in the traditional manner so far: route continuous sound like pad or loops to compressor, then sidechain a split of the kick into the comp to create that pumping effect. pull out the kick and viola a whole mass of sound escapes the kicks clutches and wham you have chaos. Bring the kick back in and pow…you have a fat pumpy beat :)

    It will be fun to try this new complicated method. How you you get your head around all this?

    all the best

  6. Phillip Says:

    Thank You Very Much ! ! ! ;-)

    With Much Gratitude Dude ! ! ! ;-)

    You’s Da Man ! ! ! ;-)

    One Love.

    God Bless.

    Learning for a lifetime. ;-|

  7. Peff Says:


    I’m not too familiar with the compressor plug-ins in Nuendo, but I’m sure there’s a way to achieve a similar effect. You might have to render the sidechain signal to an audio track, then refer the Nuendo compressor sidechain input to the rendered track.

    With the Groove Pump patches, the compression only works while a song is running. Sorry, I assumed that everyone understood this with Combinators that rely on pattern devices like the ReDrum and Matrix.

    The Groove Pump is a processing effect. The kick drum isn’t meant to be heard, it’s simply there to provide a signal to shape compression. If you’re more comfortable with the live processing of the Daft Pump, I would recommend honing your tuning skills and relying on the audio chain.

  8. Decio Says:

    Hey, i´ve got some problem and maybe you can give me support…
    I had save some of the patches on my hd, but reason don´t recognize them and also don´t recognize the .cmb files inside the refill… do you know what´s going on???

  9. Peff Says:

    Assuming you’re using the full version of Reason 3.0, and not a demo or the adapted version of 3.0, you might be having problems with the browser because it’s looking for instrument patches. Change the field to effect patches, and they should show up.

  10. DerKollo Says:

    Hi there,

    i got some problems with my sidechain…
    May be some of u guys know what i’m doing wrong.
    My Problem:
    I made a song with 2 or 3 Sounds which are “triggered” by the sidechain-function. On this day and the day after, all was good and functional. ;)
    But now after reinstalling Windows and Reason all sidechains do not work! The Sound go’s through! It is not possible to trigger the sound anymore… Whats happening?
    Had somebody the same problem?
    I don’t know exactly weather the version i had installed before was 3.0.3 or allready 3.0.4 …could it depends on that?

    Thx, for all coming help!



  11. Decio Says:

    Well, thank you so much!!!
    Exactly, the problem was that I was looking for instruments, not combinator patches…

  12. Walter Cordone Says:

    Gracias Peff, los patches de compresión son maravillosos.

  13. hammondclassics Says:

    That was fantastic.I could never think it that way

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