big dual mono problem

[jim jedlicka]

ok, here's the deal. I have a grace 101 and I'm one of the examples I'm trying to do is record a drum machine stereo into the grace by recording 1 side of the drum machine at a time, since the grace is only mono. I'm using protools as the sequencer.

Ok you figure so what.... Well ok, I press the space bar and record a 5 bar loop for the left side of the drum machine. Take the cable out and plug it into the right side. Ok the right side is now recorded.

Now I play it back and it sounds like there is some sort of phase problem going on although it's really not out of phase. Or it also sounds like there's like a sort of auto panner effect going on throughout the 2 tracks. Now if you pan the 2 tracks up center you get this flanging effect. I tried beat detective moving it by samples etc.... no luck. Anybody have any ideas on what the heck is going on and how to fix this?

[Rail Jon Rogut]

How are you expecting to get sample accurate synchronization with your drum machine?

Rail

[jim jedlicka]

I was synching it by midi.
It's not just a problem with my external drum machine. If you try the same experiment with say a softsynth and I want to run the softsynth through the grace to get the characteristic of the grace. I had the same problem running a drum track I had on the wavestation plug using a drum sound as well as the polysix, again going through the grace one at a time, and got the same effect. I mean yeah... it would be nice to have 2 of these but I got to work with what I got. There's got to be a way around this.

[Rail Jon Rogut]

MIDI will not give you anything close to sample accurate synch. For the second pass not to phase with the original pass, the systems (Pro Tools and the Drum Machine) would both have to be running at the exact same speed on both passes.. and without using something like video black burst you're dreaming if you expect it to be consistent.

Rail

[jim jedlicka]

lets forget the drum machine example. Explain then why I can't even go out of protools with a stereo playing(real time, not recorded-one at a time- mono out) soft synth through a direct box and back into protools without getting the same effect. That's seems to me that protools is not even synching with it's self in this regard. Correct? Or what variables am I missing here? I mean, I don't have this problem at all if I do the same thing to straight already recorded audio tracks. If you don't want to explain the whole thing that;s cool, I'm sure it's complicated. Maybe you could give me some links on the dynamic behind my problem. I remember running into this problem on my fostex dmt8 10 years ago and here it has presented it's self to me again.

Thanks for the info given so far.

[DigiTechSupt]

Jim - the problem with the softsynth is that the synth itself is not going to play EXACTLY the same thing every time. Some variations in the sound due to LFO's, envelopes, etc. will cause the sofsynth to be slightly different on every playback. The only way to have it play exactly the same thing every time is to record it as audio to a track - which is why you don't see the problem with pre-recorded tracks.

[steve at Your Heaven]

A possible hack that might help, if I understand the problem,and if the midi device is consistent:

- Set up to record as [eg] 6 bar loops instead of 5 bars, with your desired loop at the start of bar 2.
- Put a short (midi instruction for a single impulse like) sound that is identical for the left and right recordings somewhere in bar 1 [eg beat 4 of bar 1].
- Record your two tracks as before.
- Line up the recorded identical impulses on the two tracks, see if that gets your desired result.
- Group the two regions together, trim the excess and the impulse.