Re: Mobius latency compensation

[Jeff Larson <jeff@zonemobius.com>]

> On Mar 24, 2011, at 3:36 PM, Louie Angulo wrote:
> in playing around with both Abletons looper and Mobius as a plugin
> there is a BPM difference when i try to use Mobius as a master with
> Ableton 

The BPM that Mobius displays is sometimes different than what
the host displays due to differences in rounding.  For example,
a BPM is almost never exactly 120, it's either 120.084762537 
or 119.7983675761 or some other precise floating point number.
But applications never display it that way, they typically display
only tenths of a beat, so the first one could be 120.0 or 120.1 or 121
depending on how you round.  Also BPMs derived from MIDI clocks
are always guesses based on measuring the distance between clocks.
Because of clock jitter this distance may change slightly over time
and you have to use a "smoothing" algorithm to pick a stable tempo.
The algorithm the host uses may be different than what the plugin uses.

So while the numbers you see in the UI may be different, it is
usually close enough.  Internally Ableton is counting clocks 
the BPM it displays is just an approximation.  

Personally, I let Mobius be the clock master when I want
to slave other plugins that are sensitive to tempo but 
are not playing loops, things like delays and panners.
When I sync with pre-recorded Live clips, I 
use Host Bar sync and let the host be the master.

Jeff