MIDI Local ON creates loop in MIDI signal?


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nixward
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Watching the MIDI video, I found something that puzzled me in the explanation of the Local ON/OFF.

As far as I know, when Local is ON on an instrument, the MIDI signal goes from the instrument (MIDI OUT) into the computer, will be sent back to the same instrument (MIDI IN), BUT will not again go to the computer because this signal is not again sent through the MIDI OUT. It will only be sent out by the MIDI THRU of this instrument.
Some instruments could have MIDI OUT and THRU combined, and that's the problem that creates the loop, not the LOCAL ON/OFF but the combination of OUT and THRU.

Nick

Projectstudio in the centre of the Netherlands. See: www.nickzwart.nl

nixward
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Local OFF is the solution

To add a comment to my comment...
LOCAL OFF is THE solution for this MIDI loop problem when IN and THRU are combined. In the video it looks like the problem is the LOCAL ON but the problem is the IN and THRU.

Nick

Projectstudio in the centre of the Netherlands. See: www.nickzwart.nl

cortone
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Local On

Nick,

The video does correctly describe the bahavior of the Local On/Off parameter.

Local On/Off controls whether the instrument responds to an *Internal* MIDI signal from itself.

So, if Local On is enabled, or ON:

Pressing a key will trigger the engine within the synthesizer. The synth will respond to this whether or not there is a MIDI cable connected from the synths's MIDI Out to a DAW. IF the correct MIDI cables are attached, the DAW will also receive the MIDI signal through the MIDI Out of the synth, and loop it back to the synth (through the return cable attached from the DAW to the MIDI In of the synth). At this point, your synth is responding to two identical MIDI signals, one internally generated and one looped back from the DAW, resulting in an unpleasant loop.

If Local On is disabled, or OFF:

Pressing a key will NOT trigger the engine within the synthesizer, i.e. internally. The synth will ONLY respond if the corresponding MIDI IN/OUTs are connected to the DAW via the MIDI cables. At this point, there is no MIDI loop, as the only signal triggering the synth's engine is the one that passes out of the MIDI Out, through the DAW, and back to the synth's MIDI In.

I believe that there is a parameter within the MIDI protocol that prevents a signal from looping in the case of combined MIDI Out/Thrus, but I am not certain of this. Another gotcha that is not mentioned in the video is that some DAW software has a parameter to enable/disable the return path to the synth, essentially a Local On/Off within the software.

Cheers,
Cory

I'm XITE'd!

nixward
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Local OFF

Hi Cory,
You are totaly right, but in the video it looked like the LOCAL ON would create a constant loop so the MIDI signal going round and round, just by hitting one note.
Nick

Projectstudio in the centre of the Netherlands. See: www.nickzwart.nl

cortone
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Local OFF

Hey Nick,

Had a chance to review the MIDI section, and I see what you are saying. AP does a good job of explaining the Local On, why it is important, and refers to the repeated notes that will result. However, he continues on to discuss the repeating loop, which is where it gets off base. Good catch!

Cory

I'm XITE'd!

nixward
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I am not OFF

Hi Cory,

Thanks, I was allready wondering if I was getting crazy. I grew up with MIDI and did some serious writing about MIDI in Dutch Magazines in the 80's, I thought I was losing it!

Nick

Projectstudio in the centre of the Netherlands. See: www.nickzwart.nl

Jeremy R
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If I'm right, the local ON

If I'm right, the local ON problem is that the notes happen twice in the keyboard. I remember doing this mistake in 1995 using MIDI OUT (which ruined my early MIDI recordings cause I had no idea how to fix it), and not MIDI THRU.

B. Harrison
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Leaving it on...

Of course one could leave the Local on in the instrument and turn it off in the DAW (in Cubase this would be setting MIDI-Thru to Inactive) - this is sometimes good if you're having latency issues.

Walk softly and carry a big USB stick

marrydavidson101
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comptia security+

LOCAL OFF is THE solution for this MIDI loop problem when IN and THRU are combined.

whoami
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Even I totally agree with the

Even I totally agree with the fact that the local on would definitely create a constant loop throughout the process . Due to which the midi signals go round and round and basically hit the same note . But even though the local on is kept on there is one solution , and that would be using a delay timer to stop the monotonous loop .

imwilliam
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I come to know

I come to know some important information after reading this blog like MIDI loop problem.I had no idea about MIDI video but this article helped me a lot to have an idea about that.

gordwait
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Agreed, I don't believe it will cause a permanent loop.

At worst, it can cause the double note problem, but I agree, notes arriving on Midi In are not copied to Midi out, but are copied to Midi Thru.
(So, yes a loop could go off in a combination Out/Thru based system..)

I usually use local on, and disable the sequencer from echoing the notes back to the keyboard that sent them.

lulka
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sure?

Are you sure about that? Iäm asking because I can't get it to work with LOCAL
OFF. But I might be doing something wrong on the other hand. Not really sure..
Best
schudnac