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SOLVED: How should I interpret these MIDI specifications?

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Johan
Posts: 4
Active Member
Topic starter
 

I have an old Roland E-15. This is from the user manual:

What can I expect from the synth according to this. The manual mentions that it's a multi timbral synth. I'd expect it to receive several midi channels, one instrument per channel. This is what omni means, right? The synth has some built in music station capabilities, where you can create multi track music. And this "GS" page refers to its midi capabilities. But in the MODE section, it mentions only Mode 3. And in the page foot it says Mode 3 is OMNI OFF, POLY. Does this mean the synth only except note on messages from one channel at a time, and therefore only one instrument patch can be used at a time.

I'm working on a laser string guitar, where I wish to let each string trigger note on events on its own channel. Each string could create only one tone at a time, but two strings could produce the same tone as two separate note on events, as well as two separate note off events (actually note on with velocity 0). I'd also like to be able to assign different instrument patches to different strings.

 
Posted : 01/02/2020 2:41 am
JohnG
Posts: 225
Estimable Member
 

It's confusing isn't it?

I must admit I interpreted the MIDI specification this way when I read it (all those years ago)!
But OMNI on/off seems to refer to the channel on which the device can receive the "mode messages".
I have (somewhere) an ancient Roland SC-8850 which can receive polyphonic data on up 4 MIDI connections simultaneously, i.e. 64 channels (via USB 1).
And that works just fine the way you want to implement your guitar controller. It too is Mode 3 or 4.

Have you tried downloading the complete MIDI specification from the "specs" page?
Here: MIDI spec.
You need to register first, it's free, then scroll down until you see "Download the Complete MIDI 1.0 Detailed Specification Document (1996)"
You can have it all for free as a pdf these days. (I had to pay for my printed copy.) 🙁

 
Posted : 01/02/2020 3:42 am
Andrew Mee
Posts: 49
Admin
 

You are close ? the Omni mode refers to how the midi device handles channel data in the message.
Simply put Omni on means that channel data is ignored and the device recieving the MIDI data will play sounds regardless of channel.
Omni off means that channel data is used and each channel can have a different sound etc.
Most devices are mode 3 (omni off/poly)

 
Posted : 01/02/2020 8:25 am
Johan
Posts: 4
Active Member
Topic starter
 

Thanks, that is good to know.

 
Posted : 01/02/2020 1:30 pm
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