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External clock deactivates all Latency offset functions ?!

Posted: Fri Jul 13, 2018 9:48 pm
by Angstrom
Hi,
when I use an external clock in Live it deactivates all the Delay Compensation functions, this means my synths are out of time!

All the Latency compensation functions are greyed out when EXT clock is used. So that means no track delays, no Automatic Latency Compensation. No Hardware offset in the External Instrument and Effect devices! In the external instrument plugin the latency hardware offset parameter is un-selectable, and in the Options menu both Delay Compensation and Reduced Latency When Monitoring are also greyed out and unselectable.

My external clock is a Beatstep Pro, and if I play a sequence on the beatstep - to my synth rack and that then goes into Ableton ... this sequence is in time. What that shows is that the clock is OK. Arturia and Ableton are in sync. SO the clock is OK, the synch is OK, but Ableton has made the audio out of time by deactivating LAtency Compensation!

The Arturia also has a midi passthrough mode when the sequencers are muted MIDI can pass through from Ableton to the analog synth racks and that Audio is normally delay compensated, but as I said ... all Delay Compensation is disabled.

If I press the Ext toggle ( top left of Ableton) to revert to internal Ableton clock, the PDC instantly kicks back in instantly and the synths are all in time. All the track delay and Latency functions are activated again

its really annoying

why does Delay Compensation switch off when an external midi clock is active? They are unrelated surely?

HAs anyone solved this?
Surely many people are using an external clock AND needing Delay Compensation? What's the solution?

Re: External clock deactivates all Latency offset functions ?!

Posted: Fri Jul 13, 2018 10:03 pm
by Stromkraft
Angstrom wrote: Surely many people are using an external clock AND needing Delay Compensation? What's the solution?
A wild guess is Ableton have to fix this. All limitations when Live is in sync need to go. Why must there be any? Grrrr.

Re: External clock deactivates all Latency offset functions ?!

Posted: Fri Aug 03, 2018 11:51 pm
by dr.mysterium
Maybe I'm confused by your question,
but might I ask how would Ableton communicate this latency back up the midi cable to the Beatstep?

The Beatstep cannot see into the future to delay itself from playing after you press play.
Your asking ableton to delay certain tracks so all tracks are aligned. If it is not controlling the Beatstep then it cannot delay it.

A solution would be for the Beatstep to have a selectable millisecond delay function attached to the midi play function.
Does the Beatstep have this function?

Are Abletons 'per track delay' functions (hidden below each fader) hidden as well in your scenario?

My suggested solution is utilizing Ableton as the master clock and Beatstep as the slave. Perhaps possibly route the midi from the Beatstep back into Ableton or through your midi interface to other instruments.

One could also route the Beatstep USB/MIDI in/out directly into an iOS device using an iOS midi/USB interface, then using the LINK APP select this interface to 'Link' the Beatstep to Ableton via Link. With Ableton Link ALL devices are the MIDI Master.

Another solution might would be to use the Yamaha Bluetooh MIDI dongle to interface the Beatstep with IOS (similarly as described above) or directly with the computer running Ableton.

Re: External clock deactivates all Latency offset functions ?!

Posted: Sat Aug 04, 2018 12:11 am
by Angstrom
You are misunderstanding. Clock is completely different from audio stream latency. separate in every way,

Imagine 4 tracks in Ableton,

BASIC SCENARIO - ALL SEQUENCED FROM ABLETON
a Drumrack (0 ms latency)
A bassline with a lookahead compressor on it (10ms latency)
A complex VST (20 ms latency)
An external audio input from an analog synth ( 7 ms latency)

We run the set and Ableton puts everything in sync (it offsets the lowest latency streams to the longest latency). The audio streams are in sync

ABLETON MASTER CLOCK SCENARIO - ALL SEQUENCED AND CLOCKED FROM ABLETON
Same as above, but in this case Ableton is sending out midi clock signals to an external sequencer which plays the Analog synth which then comes back into the 4th track.

Once again - We run the set and Ableton puts everything in sync (it offsets the lowest latency streams to the longest latency) ... But we notice the external sequencer is a little behind the beat. So we go into Lives MIDI out preference for that MIDI output and set the clock offset for that MIDID channel.
Result: The audio streams are in sync .

The CLOCK is completely unrelated to the AUDIO stream latency, if the audio streams are in sync with each other the clock merely has a relation to them as a unit. As a coherent unified stream.


---- PROBLEM SCENARIO - ABLETON CLOCK SLAVED TO AN EXTERNAL CLOCK

In this case we still have the same track stream latency relationships. [0, 10,20,7]. and we have the clock offset , which is distinct from our latency corrected streams,

BUT .... Ableton deactivates every single AUDIO offset despite them being still the same as the previous examples. Picture those streams as if they are a render -because they are locked in relationship together , those 4 tracks are in sync with each other. All we change is an incoming "what is the tempo" midi message.

So we send into live "please set the tempo to 120BPM, and here is a pulse to keep you on time" . Nothing weird. Just a simple midi message setting tempo and bar position.

And Ableton for some reason then disables every single function of the AUDIO STREAM including trackdelays,all of the fully correct latency automatic corrected delays, the play through optimisation, the manual track delays. everything is deactivated and unselectable.

I want to be very clear here.
Audio latency is UNREALATED AND SEPARATE from the clock signal latency.
And in Ableton there is facilities for both clock offset and audio stream offsetting. They are distinct.

But - When an external clock is activated ableton scraps all the PDC calculations which are just as correct as the were a nanosecond previously.


Please, if you are going to comment please try it. Activate the button marked EXT. see what happens to your audio latency controls, your track offsets. Or any latency based AUDIO function

To be VERY clear - there is no need to communicate the latency back to the beatstep. Clock latency and the audio stream latency are distinct entities with a parameter setting the offset between them in prefs->midi

Try it.