How to Run the MIDI Loopback Test


Does anyone know how the MIDI loopback test should be done? I am external MIDI synth ( Yamaha PSR) with Port 1 having MIDI In and MIDI Out and Port 2 with only Out port ( without MIDI in). The synth is connected to iMac via USB.

I am sending some MIDI events from Cubase to PSR and playback to MIDI via Port 2’s MIDI out. I would like to check the latency.

I was wondering how can I carry out the test? I have set the synth and External Instrument. But I’d like to calibrate the delay between the Synth and iMac. Here’s the test I am referring to:

Thank you,



As far as I can see, you should set it up this way:

  • play out

  • In: All MIDI Inputs

  • Out: Yamaha PSR

  • record in

  • In: Yamaha PSR

  • Out: Not Connected

Enable record on the record in track, and keep it recording.

Then select the MIDI Events of the Record In and Midex8 tracks, and open them in a MIDI Editor. Compare the results.

Thank you Martin. I will give it a shut and send a feedback.