MIDI Latency Adjustment syncing 2 Lives

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Chalupa
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MIDI Latency Adjustment syncing 2 Lives

Post by Chalupa » Fri Mar 04, 2005 2:24 pm

is there a formula for adjusting the midi latency to synchronize
2 computers using Live (master>slave) ?
or do you have to always do it by ear?

if the computers have the same audio latency, do you have to compensate at all?

Chalupa
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Post by Chalupa » Fri Mar 04, 2005 5:47 pm

bump

sqook
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Post by sqook » Fri Mar 04, 2005 5:52 pm

Funny, I was just wondering about the same thing the other day...

Actually, I guess this isn't the exact same question, but I think this would probably cover midi sync issues, too.
Last edited by sqook on Fri Mar 04, 2005 5:55 pm, edited 1 time in total.

Machinate
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Re: MIDI Latency Adjustment syncing 2 Lives

Post by Machinate » Fri Mar 04, 2005 5:54 pm

Chalupa wrote:is there a formula for adjusting the midi latency to synchronize
2 computers using Live (master>slave) ?
or do you have to always do it by ear?
Do it by ear, never trust your calculator, machines LIE!
Chalupa wrote: if the computers have the same audio latency, do you have to compensate at all?
See above :wink:
Seriously though, just turn on the clicks of both computers, and tweak the offset until you hear them start to phase out each other.

If they sound alright, you're there.

Chalupa
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Post by Chalupa » Fri Mar 04, 2005 5:55 pm

i see the same questions
but i dont see any answers
i understand the way to connect the two machines and tell one to send sync info and the other to recieve it
but how do you figure out how to adjust the midi latency except to do it by ear?
theres got to be a precise way to do it but i dont understand how to figure it out :(

Machinate
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Post by Machinate » Fri Mar 04, 2005 6:25 pm

Chalupa wrote: but how do you figure out how to adjust the midi latency except to do it by ear?
Well, that's a different question than the one you asked. Why, can't you get it to work by ear? And why are you yelling?

My guess is that machines vary. SoundCards vary. Midi interfaces vary, so latency varies accordingly. There may be some secret formula out there, just waiting to be discovered, but I'm afraid the by-ear-approach is all I can offer you. That formula would prolly be way too chaotic for us, anyway.

monarkeys
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Post by monarkeys » Fri Mar 04, 2005 6:34 pm

I'm not sure there is a precise way to do this.

I can tell you that it will take about 1/3 mS to send a MIDI clock tick message down a wire - a MIDI note on message takes about 1 mS.

So I would expect that you'll have to set the latency on the master to be at least 1/3 mS longer than the slave.

Other than that, there may be some latency for the MIDI out of the master computer, and the MIDI in of the slave - I'd expect those to be really small, but you never know. Then there's the issue of how well Live syncs up to incoming clock ticks, and whether or not there's any delay in their algorithm.

Ear is probably the best way to do this, but if you're really concerned, then you could do it by eye...
Create a clip that is a single percussive hit - load it on both computers - the exact same clip. Set up a test session and load the exact same session on each computer. Then take the audio outputs of both computers and run them into two different inputs on any computer - a third one if you have it, or either of the other computers if you don't. Make sure you are actually running the hardware audio outputs thru a patch cable and into actual hardware inputs - don't do any kind of shortcut like using Live's mixer to route the out to an in.
Then playback the two clips and record the two inputs - have a look at the result with your favorite audio editor - you should be able to measure the time delay from one to the other, and then you can adjust latency accordingly.
One point of interest would be to see if the time delay is consistent, i.e. if you measure the delay between the first hits on each machine, is that the same as the time delay between the second, third, fourth hits etc...

If I have time I'll try this at home.

Chalupa
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Post by Chalupa » Fri Mar 04, 2005 6:47 pm

sorry i didnt mean to yelled it didnt know it was going to make that big of words
i guess i will just do it by hearing
i was hoping there was an equation to make it easier but i there is not one
thanks for your helping eveyrone

plonkman
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hmm..

Post by plonkman » Fri Mar 04, 2005 8:11 pm

have an external source generate the timecode... they would both be slaves.
"Knickers!" - Syd James 1913 - 1976

sweetjesus
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Re: hmm..

Post by sweetjesus » Fri Mar 04, 2005 8:12 pm

plonkman wrote:have an external source generate the timecode... they would both be slaves.
As Fingaz would say.. 'werd'

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