Just want to make sure you’re aware of the difference between word clock and midi clock…
I’ll start with word clock…
If you want to integrate more than 1 digital audio device in your system, you will need word clock.
If you have, for instance, your Motu AV, connected to a digital mixer, and they are both running on internal clock,
ie both are clock MASTERS, you will definitely hear clicks and pops over time. This is because they are clocked independently. THe way to avoid these clicks and pops is to make 1 device a master, and the other a slave. This is achieved by connecting a word clock cable [generally BNC to BNC] between the word clock OUT of what you designate as the master to the word clock IN of the slave device, and selecting Word Clock slave on the Slave!!. Which one as master/slave??? Depends on how “good” the clock is. There are heated arguments as to the quality of different word clocks - better stereo imaging, 192 Khz vs 96kz v 48k/44.1k… At a minimum, either as Master and the other as Slave should end your clicks and pops. If you have more digital devices, a master synchronising clock with multiple clock outs should be used to feed all the digital devices in your system, guaranteeing a common reference.
For example, my system has 3 computers - Comp 1 has RME MADI and Raydat interfaces [over 100 channels of audio in and out], Comp 2 has RME 9652 [26 chnls i/o], and Comp 3 has MOTU 2408. An SSL MADI AX converts analog outputs from various synths feeding into Comp 1. THere is a DAT machine, an AKAI S5000 with 8 digital outs, a Roland XV5080 with 8 digital outs. THe AES [digital stereo] output of Comp 1 feeds a TC Finalizer 96k, which returns to the Computer to print a stereo mix. There are other digital devices in the system.
All are clocked via a Swissonic WD8…the system works extremely well, and other than pilot error from time to time, I have been very pleased with its operation for the last number of years.
NB…the only thing transmitted from the Word Clock Out, is digital audio synchronising data.
On the other hand,
Midi Clock is part of the MIDI protocol, and is transmitted with other messages through the 5-pin DIN - also know as MIDI-cable.
Midi Clock is tempo-related. A device sends 24 Midi Clock messages per quarter note. If a project has a tempo of, let’s say, 120 bpm, that means there are 2 quarter notes per second, i.e. 48 Midi Clock messages.
These MIDI clock messages are generally used to :
1] Synchronise two MIDI sequencers - you could have a software and a hardware sequencer, and synchronise them, so that they would consistently run relative to each other.
2] Control audio devices that have “timing” functions, eg delay units…Midi Clock output from a Master [eg your Cubase program] will “tell” such a device what the bpm is, and it will calculate delays accordingly. Changes in tempi on the Master will be observed on the slave device.
SO!
There is no direct relationship between Word Clock and Midi Clock…they are two completely different protocols,
Digital audio systems will work quite well without Midi clock, and trying to put word clock into a delay device will not give it tempo information!!
The answer to your first question is down to “How much” info is on the Midi line. Some years back, I would have had perhaps 30+ Midi instances [Midex 8 + 2 Yamaha 256’s etc] - ie 30 Midi cables worth, each going to and from a seperate device - in use, so as to avoid any clogging. This has been much reduced in the last few years, with plug-ins inside the DAW, and with VSL Ensemble PRO running on the slave computers via ethernet.
Sorry that this has moved away from your opening question, but you seem to be following where it’s going, so hope this helps.