Re: MIDI sync with Time Signature Retention

[Matt Walsh <matt1walsh@gmail.com>]

Thanks folks. This is very helpful. I think I have isunderstood some things and left some other pertinent info out. ;)

I will not be changing time signatures; but I will be doing a lot of 5,6,7.  A scenario: I set up a 2 bar loop on my MPC60 at a tempo of 130 BPM in 5/4. I create a rhythm/synth/sample track. The loop on the looper should be the same as the loop on the MPC. Time signature as such is actually not important. It just needs to be 10 beats at 130 BPM. The looper should also responding to the Play/stop commands on the MPC, so it should already be playing the empty loop in sync with the MPC loop. 

When I hit record I am essentially "punching in" over the synth. I will be feeding a mixer and singing/playing drums over the MPC base track.

Is this clearer? Again, thanks for all the help!

Best,
Matt

On Fri, Sep 17, 2010 at 1:53 AM, Dustbunnies <mech@m3ch.net> wrote:

At 12:50 AM -0400 9/17/10, Matt Walsh wrote:

I'm somewhat new to audio looping. I have been doing a form of looping by building up tracks with my Akai MPC60 and sampler. I am thinking about syncing some audio loops into the mix, as it were.

So I am thinking of getting a real-deal audio looper. It will need to slave to to the Akai, and it will need to be a piece of hardware. Thing is, it will not only need to slave tempo, but will need to slave time signature as well. I'm not opposed to having to load a patch that has this data in it, if need be. But it definitely needs to respond to play/stop commands and stay in sync with the MPC.

Thoughts?

You may be out of luck as far as hardware goes, since I believe that almost all hardware units respond to Midi Clock Sync and MMC (Midi Machine Control) commands.  IIRC, Time Signature is a rather esoteric specification buried in MTC (Midi Time Code), which there is little reason for audio loopers to implement.  (Even back when I did a lot of soundtrack and post-production work, we never bothered with that function.  In fact, I'd forgotten it existed until I just did a search)

MTC is mainly useful when syncing to SMPTE.  In most setups, you'd want to be able to shuttle to different parts of a composition and have all the instruments immediately know which section of the score at which they should begin.  Since most loopers merely record an audio loop then replay it over and over (yes, I know I'm oversimplifying here guys) there's little advantage to MTC over Clock Sync + MMC, so most manufacturers don't bother with it.  In fact, I can't think of any hardware loopers at all that support it off the top of my head.

I'm curious, though, why this is a requirement?  Are you going to be recording a loop in realtime and then suddenly changing its time signature?  If so, then there are perhaps some other functions that might assist you with doing that rather than using the MTC spec.  For instance, changing 4/4 to 3/4 would be rather easy by simply truncating the loop.  4/4 to 7/4 would be a 2x multiply, then a quick truncate from 8 beats to 7.  Many other time signature changes are going to be very difficult with recorded audio data, however.  But, then again, merely changing the time signature via MTC spec isn't going to do any deep editing of the lines either.

If you can give us some idea why you need this over just standard Clock + MMC, maybe we can help with a more comprehensive answer.

FWIW, a few hardware loopers I know if that support Clock are the Looperlative, EDP, and Repeater.  Probably a couple more I'm forgetting too.

       --m.
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