MIDI Latency

[marshborn]

Hey guys, long time listener, first time caller. I have been chasing (and failing miserably) a MIDI latency issue that only shows up after a session starts to get some tracks rollin. Upon start of a fresh session, the latency is non existent. MIDI instruments respond instantly to the RD300 (I know I know I know, it was a pawn shop buy for the weighted keys and midi functionality). But at a certain point in the day, latency gets so bad the keys are unplayable. If I save and start a new session, it's gone. I'm running a 2017 iMac Pro (1T SSD, 16G) with PT2020.12, Slate Digital VRS8 (using the MIDI in port), buffer at 64, low latency monitoring on, yada yada yada. It's been an ongoing nightmare for months now. Before the VRS8, I had a MOTU, same issue. Before the MOTU was a Digi003, same issue.Bought a USB MIDI device, same issue. I can't for the life of me figure it out. Any insight would be greatly appreciated. I'm getting tired of dumping an MP3 of my session and importing it into a new session just so I can lay down keys. Only to fly them back in. Thanks in advance!

[musicman691]

MIDI latency has always been an issue in PT. Are you saying it increases as your recording day goes on? Never heard of that. I do a LOT of MIDI recording with my ancient Motif 7 into a Motu MIDI Timepiece AVUSB and have no issues with latency changing through the day. Are you sure it's not audio latency that's changing? Not heard of that either but had to ask.


When you tried your USB MIDI device (what was/is that?) how did you connect to your iMac Pro?


Is this happening with all your softsynths and are they synthesis or samplers? Any UVI Falcon stuff?

[marshborn]

I have a Roland RD-300 and an Akai MPKmini as my main MIDI controllers. I thought at first maybe the Roland was the issue but it happens on both devices. The audio latency doesn't seem to be an issue. The USB is an M-Audio 2x2. No Falcon stuff.

[ChuckS]

Using any plugs on the Master? If so, try eliminating those.

[ArKay99]

Just wondering... Have you opened the system resources window and looked at the cpu load, disk usage, memory allocation, etc.? Have you verified delay compensation parameters in Preferences? Also, IIRC there is a MIDI offset parameter somewhere. Have you tried turning off DC? Turning it on? Latency drives me nuts, so I get it. However, if its delta is growing there must be some mechanism that is multiplying the error. Maybe verify it's not something with Local control and a monitoring issue. Just spitballing here. These are the things I would try, and have when I've run into issues like this. When you're getting the latency and it's a long lag, how do the recorded data, notes, etc. line up? against the other audio tracks in the timeline?

[marshborn]

You've got to be joking. Removed my masters plugins and it's fixed. Thank you ChuckS! It's seriously been months of smashing my face against the keyboard asking "why god! What have I done to deserve this!". I suppose as the tracks start to come together, I start adding master bus processing and that's why it seems like it's the track count. Thank you guys for saving what little sanity I have left! Cheers DUC!

[JFreak]

MIDI 1.0 standard says there is 24 clock ticks per quarter note. How long that is obviously depends on tempo, but let us assume 120bpm for easier math. That would mean 2 beats per second or one beat per 500 milliseconds. That would make 10.4 milliseconds per tick which is the accuracy of MIDI 1.0 spec.

I hope you can live with that while complaining sub 5ms monitoring latency is too much.

Also because MIDI is serial protocol any message requires 1ms for transmission, and most notably can only send one message at a time. This means if all your 16 channels are transmitting at the same tick it is up to 16ms latency on the last channel to receive message, and MIDI latency comes on top of that. So in real life one of your channels may have +26ms latency.

Interesting to see how MIDI 2.0 changes things.