Sloppy midi playback of VST drums: SOLVED

[smckee]

Well this is embarrassing--and apologies to those who spent time replying--but I just discovered that I had left the Cakewalk FX Quantize in the effect rack of my drum channel, with Random enabled and set at 15%.   If you're having trouble like I describe below, check that you don't have this effect on.

 

When I record midi for a VST drumkit, during playback, I am hearing variable timing issues.  It  may playback correctly one time out of 4 or 5 playbacks.  You  might notice it on a string patch for instance, but on a drum track--particularly on rolls--the "feel" of the drums is inconsistent.  I have experimented with buffers and  quantization.  I've edited rolls with quantization turned off in an attempt to subtly (or not so subtly) massage the feel of the roll.  Nothing is working.   Playback seems to be the issue--not input errors.   I know that midi is not perfect, but this goes beyond inherent midi imperfections.  Any suggestions are appreciated.  Thanks!  

My rig is a Lenovo Windows 10 Laptop, Cakewalk by Bandlab, and an Apollo x8p.

 

 

Edited March 11 by smckee
SOLVED

[David Baay]

Which drum kit, and are you monitoring the kit's brain through CbB or directly, or using a VSTi?

Either way, I would record the audio from MIDI playback, sync the first audio transient with the first MIDI event, and see if there's a significantly variable timing discrepancy between later MIDI events and their corresponding transients. There should be virtually none with a VSTi and if you're monitoring the kit's brain, jitter in the MIDI interface and the brain's response would usually be on the order of only 2-3 ticks (1.0-1.5ms at 125bpm) which shouldn't be noticeable.

EDIT: Seems I wasn't reading carefully and missed that playback is through a VSTi and maybe you're just recording MIDI from a keyboard rather than electronic drum kit as I originally thought. My suggestion still applies in any case: check the audio transients of a realtime synth recording against the MIDI to verify what you're hearing is real. Then maybe try a freeze/fast bounce to see if it's different.

Edited March 9 by David Baay

[John Vere]

 

[smckee]

On 3/8/2024 at 5:43 PM, David Baay said:

Which drum kit, and are you monitoring the kit's brain through CbB or directly, or using a VSTi?

Either way, I would record the audio from MIDI playback, sync the first audio transient with the first MIDI event, and see if there's a significantly variable timing discrepancy between later MIDI events and their corresponding transients. There should be virtually none with a VSTi and if you're monitoring the kit's brain, jitter in the MIDI interface and the brain's response would usually be on the order of only 2-3 ticks (1.0-1.5ms at 125bpm) which shouldn't be noticeable.

EDIT: Seems I wasn't reading carefully and missed that playback is through a VSTi and maybe you're just recording MIDI from a keyboard rather than electronic drum kit as I originally thought. My suggestion still applies in any case: check the audio transients of a realtime synth recording against the MIDI to verify what you're hearing is real. Then maybe try a freeze/fast bounce to see if it's different.

Yes, I'm recording vst drums via a midi keyboard.  I will look into this, although I am definitely hearing problems-fast doubles on the toms for instance, sometimes drag on playback,  at other times, they almost flam.  I will check that it's not an issue with the VST-Modo drum.  Thanks!

UPDATE: Checked it with a different drum VST: same results.  I looped a section where the toms do a kind of Latin style feel, and the doubles lag noticeably on some playbacks, not on others.  (The "almost flams" I mentioned hearing were caused by me going in and nudging the doubles together to try to tighten them, but overdoing it.)   I'm not hearing anything in the way of too-fast doubles--just an obvious lag on some playbacks.    

UPDATE WITH IMAGES: 

I selected a region of the vst drums, and exported it to audio six times, then imported all six into a blank project.  See jpeg "TOMS"  Not only do none of the exports line up with each other, but the space between the two Tom hits (center of the jpeg) varies quite a bit.  It's clearly audible on playback.  You can't nudge these tracks together to line them up with each other.  In contrast, my Vocal clip of the same region, exported six times and stacked up, matches exactly, as you would expect, and sounds like a single vocal take on playback.  It could be that Cakewalk does not consistently render visual representations, but the visual discrepancies on the Tom jpg do reflect what I'm hearing.     

Edited March 10 by smckee
Updates

[Starship Krupa]

On 3/8/2024 at 5:27 PM, smckee said:

I had left the Cakewalk FX Quantize in the effect rack of my drum channel, with Random enabled and set at 15%

At least it's nice to know that it works pretty well.

[David Baay]

Good one.