Audio crackles when midi and audio in same session

Hello,

In one GP session I try to process my midi keyboards inputs and apply audio effects from my Motif XS Rack at the same and have audio crackles.
I have tried many conf and can’t explain what is wrong.
The crackles seems to appear during midi activity but I haven’t noticed to many messages in the monitor.

  1. First config (KO):
    Arturia Keylab61 (USB midi) → GP → Motif Rack XS (USB midi)
    Motif Rack XS (audio) → X32 console (USB card) → GP → X32 console (USB card) → Monitors

In this configuration I have audio crackles even with high buffer value (1024).

  1. Second config (OK):
    If I do the same thing with two separeted GP session I have no problem, even with low buffer size (128)

Arturia Keylab61 (USB midi) → GP (session 1) → Motif Rack XS (USB midi)
Motif Rack XS (audio) → X32 console (USB card) → GP (session 2) → X32 console (USB card) → Monitors

Thanks for your help.
José

After trying others configs I have the same problem.

  1. KO : audio crackles even with buffer = 2048
    Crackles
  2. OK with buffer = 128
    No-crackles

The midi ports ‘express 128’ do they require there own ‘tailored’ drivers, or do they use the standard Windows drivers?

They require there own drivers.
I have the exact same issue with Motif XS Rack USB midi interface, with yamaha drivers.

I suspect some conflict between the midi drivers and the audio drivers, although I cannot confirm that myself. Maybe someone else on the forum has the same device(s)?

Edit: Never mind. I think a midi feedback loop is more likely.

MOTU MIDI Express? It seems that you have an additional MIDI patchbay that you didn’t describe in none of your above described configs. If the MIDI out of the patchbay is configured a MIDI out+thru, you could va he a MIDI loop which would cause some troubles like crackles.

Did you try to put a GP MIDI monitor between the MIDI in express and the MIDI out express?

When are your crackles coming from ? From some plugins or from one of your hardware synth?

He seems to be sending incoming mid on port 8 right back into the MOTU on port 8

Exactly, which depending on the internal routing could cause MIDI loop issues.

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Thank you very much for your help, I have fixed the issue.

You were wright, there was a midi loop, not from MOTU Express, but from a “thru” option in the Motif Rack XS editor.
In some circonstances, the USB was overloaded by Motif USB midi inputs/outputs and produced issues over others audio and midi devices. It can explained why the problem occured in so different configs.

Finding the loop finaly drives me to the real problem. From the Motif manual : the only working Midi input port for instrument is “port 1”

Page 18
"• Port 1
The tone generator block in the MOTIF-RACK XS can recognize and
use only this port.
When playing the MOTIF-RACK XS sounds from an external MIDI
instrument or computer, you should set the MIDI Port to 1 on the
connected MIDI device or computer"

Modifying the “Motif editor” keyboard input, and disabling “thru”, has fixed all issues :slight_smile:

MOTIF Rack XS is realy an impressive expander but it’s also a complete nightmare to use without tools like Gig Performer !
Realy happy to find a solution to continue to use this powerful device.

Best regards,
José

Yes, it’s hard to tell you more about the problem if we don’t know exactly how your devices are wired and what kind of crackle you get at which audio output. However, connecting a MIDI input to the same MIDI output is risky if the output merges a MIDI thru. There was indeed a MIDI thru involved elsewhere, so I’m glad if I could point you to the issue. :wink:

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