Re: Sooperlooper or Mobius? Going back to software.

[kkissinger@kevinkissinger.com]

The buffer sizes are set in the ASIO driver software that comes with  
the RME800.

Cubase, in turn, measures the latency and does the correction  (and  
also displays the latency values.)

For live looping, one must consider the "round trip" amount (that is,  
the sum of the inbound and outbound latency).

Indeed, there is some processor latency, too -- however I've never  
noticed it with my computer (4gig ram and a 3.4ghz CPU).  The only  
time processing latency becomes a factor is for granular effects   
(i.e. pitch-shifting).  Most pitch-shifters allow you to specify the  
grain size in milliseconds.

However, I am now off on a tangent -- and while I'm there...

I will comment on one last year's pet projects: namely to sync  
external loopers with my laptop via MIDI Clock.

I lost a lot of time and energy trying to get this to work -- and  
finally abandoned the notion and decided that when I use a laptop, I  
will loop with the laptop, and when I use an external looper, I will  
NOT use it with a laptop (or at least, won't try to sync it to the  
laptop).

The problem has to do with the computer's MIDI Clock stability.  When  
I experimented with the LP1 and my laptop, I discovered that I could  
get drift and glitch free performance when I reduced the PCI load to  
the bare-bones minimum.  That is, I minimized all windows, and reduced  
the bandwidth to my RME800 to the minimum number of channels I needed.

However, with windows open, there is more data traveling across the  
PCI buss to the video card  (I've already disabled all networking  
devices except for USB and Firewire).  This caused the MIDI Clock to  
be just unstable enough to cause occasional and unpredictable glitches.

In the past, I never could sync my RC50 to the laptop -- likely the  
same issue.

Computers sync up with SMPTE Clock ok -- and will likely work ok with  
MTC (Midi Time Code), but computer-based MIDI CLOCK hasn't worked well  
for me.

I have had some success using the delay on my (vintage) DPS-V55 to  
record short loops on the laptop.  The laptop sends TAP messages (via  
MIDI) to the DPS-V55 and then records the resulting taps to a short  
loop.  Once the loop is recorded, the DPS-V55 has done its job -- the  
loop plays and that is that.  (In other words, no need to sync the  
DPS-V55 and the laptop).

However, MIDI Clock works great for sending out clock pulses that  
otherwise aren't sync'd.  I've been messing with my RC50 -- sending  
MIDI CLOCK from the RC50 to my analog (modular) synth's MIDI to CV  
converter.  The converter converts the MIDI START to a "reset trigger"  
and the MIDI Clock messages to Clock Triggers.  I use these triggers  
to step my sequencer and Voila! -- my synth plays in sync with the  
RC50, tracks all the tempo changes, etc.

OK OK... I probably should create a video or something to demonstrate  
this stuff -- I'll add it to the "do list".

Forgive my tangent here... the issue of latency leads to the issue of  
hardware, external devices, and sync and then my mind runs amok.

-- Kevin








Quoting Warren Sirota <wsirota@wsdesigns.com>:

> I think you have to set the buffer size in *both *the client   
> applications *and
> *the control panel for the interface. Not sure, but it can't hurt!
>
> On Wed, Jan 14, 2009 at 1:30 PM, Per Boysen <perboysen@gmail.com> wrote:
>
>> What is this "firefox"? Not the web browser I guess....? (sorry for
>> not following fully here)
>>
>> Generally, on Mac the settings for whatever external audio interface
>> you are using is to be found within the audio application that makes
>> use of that piece of hardware. To take the FireFAce as an example:
>> it's not, as you seem to believe, in the RME console you set the
>> buffer - it is in MainStage, in Mobius, in Bidule, in Cubase etc. So
>> when using many applications together you should make sure that all of
>> them is set to the same audio interface buffer.
>>
>> Per
>>
>>
>> On Wed, Jan 14, 2009 at 7:06 PM, L.Angulo <labaloops@yahoo.com> wrote:
>> > well it would be nice to be able to do this with the firefox,like with
>> the RME,there you have the fireface settings you can tweak nicely but 
>there
>> is no way to do it with the firefox on a mac,or perhaps i am missing
>> something,anybody using this two?
>> > cheers
>> > Luis
>> >
>> >
>> >
>> >
>> >
>> >>
>> >> Yes, of course it has! If you change the audio buffer in
>> >> the driver it
>> >> will affect latency. When using my RME FireFAce400 I set
>> >> the buffer to
>> >> 128 in MainStage. And the same in Mobius. And the same in
>> >> Bidule. If
>> >> different software that deals with the audio hardware does
>> >> that with
>> >> different buffer settings you get a wobbly system. In
>> >> Windows, on the
>> >> same MacBook I used to set all audio applications to 256
>> >> samples
>> >> buffer for the audio hardware. That felt the same as 128 on
>> >> Mac. It
>> >> seems Windows XP is a little faster, not having the
>> >> "security zone
>> >> buffer" of OS X. I'm not technically interested so
>> >> these are just the
>> >> way I've heard more tech minded folks explain it.
>> >>
>> >> Greetings from Sweden
>> >>
>> >> Per Boysen
>> >> www.boysen.se
>> >> www.perboysen.com
>> >
>> >
>> >
>> >
>>
>>
>
>
> --
> Warren
> http://www.ubetoo.com/Artist.taf?_ArtistId=6679
> http://www.warrensirota.com
>