MIDI Clock Latency - CME WIDI Master | L6 Helix

rushak

Hi ST3 Family,

I did a search and couldn't find a related topic to what I'm experiencing. Wondering if anyone else has experienced MIDI Clock sync/latency issues with a Helix (or another modeler) using a WIDI Master?

Ideally, I like to run 1 Helix preset for a setlist and have ST3 send MIDI CC to change snapshots, etc. along with the MIDI clock per song to my Helix. My goal is to be 95% free of tap dancing on the pedalboard and amazingly, ST3 has it more than covered! I just can't figure out how to get the MIDI clock to be reliable. However, I run into varying results via USB (more consistent) and WIDI Master. The tap tempo light on the Helix is never constant and varies during playback, but I never really heard anything off with my delay effects until I started using the WIDI Master. I can hear the tempo changing during ST3 playback of a single song which produces an undesirable effect. I've notice that if the tempo is fast, maybe over 200bpm...the tempo seems to be half the speed based on the visual cue I see on the tap tempo light.

I've tried changing the WIDI Master to "low jitter" mode with no change in results. I also updated the WIDI Master firmware to the latest with no change in behavior.

Not sure if the root issue lies within the Helix, WIDI Master, or ST3. For reference, I used to use a POD Go via USB and the tap tempo light would exhibit the same symptoms of not being constant at times. I never heard any tempo artifacts in my time based effects so I just chalked it up to a POD Go quirk.

Thanks for your time,

Jason

peter

Unfortunately the way midi clock works is by sending midi packages with a very high frequency (24 packets per quarter note). So with a tempo of 120 it will send 48 midi packets per second and the receiver will calculate the tempo based on the time between 2 packets. Now depending on the implementation of the receiver there might be some averaging done to prevent unintended tempo changes but that means that intended changes are delayed. So this a tradeoff that each product needs to make.

With bluetooth the jitter is very high compared to a cable connection. So tempo calculations are very unreliable.

Maybe you can set the tempo with a CC message at the beginning of a song. That would always work well.

rushak

Hi Peter,

Thanks for the insight and it certainly makes sense. I did try sending time-coded CC commands (converted bpm to seconds)that emulates the tap tempo FS of the Helix, but those results weren’t consistent either. That seems to be the only option to control the tempo via MIDI with the Helix outside of clock sync. Certainly not the end of the world as I can just manually tap tempo as needed. I’ll continue to play with it when I time permits.

Thanks,

Jason

peter

Looking at the manual I guess you could use the CC 64 command to change tempo between 64 and 127 bpm. A bit limited but better than nothing I guess.