Timing Jitter Loop Back Test Setup(Participation Request)
This test uses an electronic drum kit since it can be controlled using audio. By hooking up an audio output to the input of a drum sensor, you can trigger a "drum hit" that the E-drum module will convert to midi.
This can be represented by the loop
[Reaper] Click Track -> [Audio Interface] Line Out -> [EDrums] Sensor -> Module -> Midi Out -> [Audio Interface] Midi In -> [Reaper] Recorded Midi Track.
With such a setup, we can compare the latency between the click track in reaper and the final recorded track.
Having done so, my results are around 6ms average and 11ms max jitter. From reading online, this seems to be a bit unacceptable.
I've written a python script that computes the jitter between midi note clusters(notes within 50ms or so are considered to be in the same group) in a midi item. Once the track is recorded, you'll have to add the midi notes by hand(or glue a pre-created midi click to the recorded one).
I'm interested in what kind of results others gets.
The gear used in the test: i7-6700k, 16GB DD4 mem, etc; US-1800 Audio Interface, Roland V Drums.
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The test was just hacked together when I get the bright idea to use the drums as a way to do midi loop back timing test using audio as a controller(since the drums I have do no have an input which can then). One can achieve a similar test that only includes the audio interface(loop back on the midi ports). I suppose that is the next test to do, as it will allow one to know the jitter the midi drums have themselves, which allows one further break down the analysis.
If someone has an improved testing method with scripts to do the calculations or ways to improve the jitter, I'd appreciate it. Obviously as a drummer, it is important to minimize all latency and jitter issues as milliseconds matter.
(I have a theory that if you have x ms latency and use an E drum kit, then when you practice, you compensate by x ms to "be on the beat". Then when you get on an acoustic kit you tend to rush by x ms because the latency is not there. This is generally not a big deal until you start trying to sync stuff up with an acoustic kit and your constantly in front of the beat, yet your fine on your e-drums)
Last edited by Airal; 09-04-2016 at 04:49 PM.
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