Elektron Musical Instruments

Correction to my last post below: my numbers are WRONG.  I used an incorrect conversion method.

These should be the correct time data points from my MD tests:

MD triggering itself (MAXIMUM): 97 samples ~= 2.2 ms
MD triggering itself (AVERAGE): 64.428 samples ~= 1.461 ms
MD triggering MC-80 (MAXIMUM): 90 samples ~= 2.041ms 
MD triggering MC-80 (AVERAGE): 30.533 samples ~= 0.692 ms 
MD triggering Nord (MAXIMUM): 64 samples ~= 1.451 ms
MD triggering Nord (AVERAGE): 20.333 samples ~= 0.461 ms

Here is the formula I used:

T_deviation (sec) = Sample_deviation (samples) / Sampling_frequency (Hz)

So for the max deviation, for example:

T_deviation (sec) = unknown
Sample_deviation (samples) = 97 samples (as measured in Sound Forge 6)
Sampling_frequency = 44100 (file recorded at 44.1kHz)

Therefore, T_deviation = 97/44100 = 0.0022 seconds = 2.2 milliseconds

I also double-checked this conversion in Sound Forge (even though Sound Forge truncates after the thousandths decical place in the time display) and it checks out OK.

Therefore, I should change my statment of the MD triggering external MIDI devices: I think the average deviation between quarter notes is minimal if the external MIDI device has a tight internal engine, because a half-milli-second of "slop" is below the human hearing threshold.  However - the maximum deviation of 2.2 ms of the internal MD engine is definitely within the realm (although definitely at the hairy edge) of human perception limits.

However, all of this does not cover a more realistic scenario where the MD is playing multiple MIDI notes over one MIDI cable simultaneously, or playing multiple sounds internally.  Whether or not I feel like going and doing those sorts of measurements... not really.  That's not really my job.  ;-)  Though I hope someone out there is taking this as seriously as I am!

Sorry for any confusion caused by my initial message.
Scott



  ----- Original Message ----- 
  From: Scott 
  To: elektron-users@yahoogroups.com 
  Sent: Monday, April 16, 2007 11:43 PM
  Subject: Re: [elektron] timing


  Exactly.  You would think that would be the case, but things are not what they always seem sometimes.

  The disenchanting part is that the timing gets better when using the MD to trigger other devices over MIDI.  This suggests, as I mentioned, that the slop is not only due to some random bug in Elektron's sequencer code, but it's also due to the internal synthesis engine of the MD.  This leads me to speculate this could be an impossible situation to improve to a level where it would match devices like my MC-80 or Dave's MPC.

  Here are some more interesting numbers.  Instead of looking at "maximum deviation" of samples between quarter notes, consider the average deviation:

  MD triggering itself: 56.375 samples ~= 19 ms
  MD triggering MC-80: 30.533 samples ~= 10.5 ms 
  MD triggering Nord: 20.333 samples ~= 7 ms

  Ironically enough, I recall setting my "MIDI offset" in Ableton Live to right around 19ms when I had Live synced to the MD.


    ----- Original Message ----- 
    From: Patrik Rydberg 
    To: elektron-users@yahoogroups.com 
    Sent: Monday, April 16, 2007 3:37 AM
    Subject: Re: [elektron] timing




    Scott skrev:
    > 
    > 
    > MD original triggering its own internal rimshot: 97 samples / 33ms (once 
    > every 4 measures)
    > MD triggering the MC-80 rimshot: 90 samples / 31ms (once every 4 measures)
    > MD triggering the Nord pulse: 64 samples / 22ms (once every 4 measures)
    > 

    Interresting...

    > Returning to the MD, however, reexamining the numbers:
    > 
    > 33ms internal MD sound
    > 31ms external MC-80 sound
    > 22ms external Nord sound
    > 
    > It seems there could be as much as 33% of the MD's overall timing slop 
    > could be due to the synth/sample playback engine, whereas the remaining 
    > 67% could be due to the sequencing engine. This is by no means an 
    > exhaustive scientific study, however, a preliminary one whose results 
    > are a bit intriguing...

    Well, the way I see it, if the Machinedrum is running on internal clock, 
    triggering its own sample engine from its own sequencer, the timing has 
    every possibility to be very accurate, not just as good as triggering 
    external synths via midi. Using MIDI, you have all the problems with the 
    midi protocol. Internally, between the MD sequencer and synth engine, 
    why use midi? Compare the situation to a DAW. When triggering external 
    midi stuff they are sloppy, but when triggering VSTi:s the timing is 
    sample accurate.

    /Patrik
    www.cutpaste.org



     

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