On Sat, 2 Jun 2018 00:12:58 +0200 Robin Gareus <robin@xxxxxxxxxx> wrote: >On 06/01/2018 11:45 PM, Will Godfrey wrote: >> On Fri, 1 Jun 2018 22:50:50 +0200 >> Robin Gareus <robin@xxxxxxxxxx> wrote: >> >>> On 06/01/2018 09:00 PM, Will Godfrey wrote: >>>> Something just occurred to me. >>>> >>>> Does anyone know if this is transmitted any faster if going computer to computer >>>> rather than between hardware devices. So do you get lower latency? >>> >>> You have more bandwidth but not usually lower latency. >>> >>>> Also what about keyboards that work entirely as MIDI over USB connecting to a >>>> computer? >>> >>> Depends on the keyboard. >>> >>> It seems that may chipsets still use the 31.25kbaud (probably because >>> you can get USB to physical MIDI ASIC cheap off the shelf). >>> >>> You can check with jack_midi_dump (or similar). Elbow press/release >>> 30-40 notes on a keyboard and check if most individual note events are >>> spaced less than 1ms apart. If they are, then the interface is faster >>> than physical MIDI. >>> >>> ciao, >>> robin >> >> Now why didn't I think of that? >> Thanks Robin :) >> > >I just tested with a M-Audio Oxygen 49 (which only has USB MIDI) > >I've used an A4-book to press/release 14 white keys, recorded it with >Ardour. The 14 note-off events span 220 samples (@48kHz, ~4.5ms). > >So the device has a higher bandwidth than physical MIDI (approx 3 >times). I can't say anything about the latency though. > >All other devices that I have here do have an physical MIDI port (5pin >DIN) and are only 31.25 kbaud have ~2.0ms round-trip latency. > >Cheers! >robin > >PS. note-on events are spread out further because I didn't manage to >press the book (or elbow) down accurately enough. That is actually very interesting, and useful. With hardware MIDI a two-handed 4 note chord (so 8 total) has a 'ripple' of at at the very least 8mS. Although a musician is likely to be more varied than that, something like a drum machine wont, and this effect can be very noticable. it would suggest that where you have a keyboard with both options you should use USB for preference. I have a Miditech pro49 that has that combination, so must check to see if that's true, or if the two outputs are locked together. -- Will J Godfrey http://www.musically.me.uk Say you have a poem and I have a tune. Exchange them and we can both have a poem, a tune, and a song. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx https://lists.linuxaudio.org/listinfo/linux-audio-user
