Did some latency testing on MIDI echoed on the MIDI Out vs MIDI Thru ports of the Yamaha VL70-m.
Data appears on the MIDI Thru port before the MIDI Out port by about 6-7 msec. Significant difference! I had planned on using the VL70m as a MIDI splitter, but thought I would test this first, and … Glad I did!
I’m on a crusade to reduce latency in my rig, so all corners are going under the microscope. This one I thought might be of particular interest to others …
The Yamaha unit does echo MIDI In to the MIDI Out port, but there is a configurable option to filter based on channel. I should have noted that the VL70-m for this test was in VOICE mode with System/NoteFilter set to Thru.
I am guess that the configurable options require a rather lengthy trip through the processor to do this filtering.
Yes, anything involving processing is going to add the latency of processing unless Yamaha are really clever and have a way of doing it in hardware.
I used to run my old gig rack of Nord G2, Motif Rack ES, FS1r and A4000 (at the time) as a MIDI IN / MIDI Thru chain, with a PC with Cantabile on the end of the chain and I never noticed any latency. If all of those devices had “soft” MIDI throughs as opposed to “hard” MIDI throughs then it would have been noticeable. But a hardware MIDI through would have sub microsecond latency, probably much less in the order of nano seconds.
I did measure the loopback latency of the MIDISport USB <=> MIDI conversion, and it is almost exactly the reported 6.71 msec latency of the VL70-m MIDI In => MIDI Thru time … so the actual latency is around 0.02 msec - but it is too small for a reliable measurement by my system … I guess I would need a scope for that …
Just tested the latency of a little Mackie Mix 5 mixer at around 320 nanosec … not really sure what contributes to that latency (internally to the mixer) …