Sync drift between tape and ACID Pro 3

[linus]

I searched and can't find anyone describe this problem so I'm hoping someone can help me out.

First the problem then the detailed set-up:
Problem: ACID Pro 3 and My tascam 38 will sync up but there is a noticable drift. NOT as subtle as "flanging" but not so noticable that I picked up on it right away. It could best be described as rushing and dragging the beat making playing bass along with the drums (in ACID) a frustrating experience)

The Set-up: I created a drum track using ACID Pro 3 on my PC (Dell Pentium4/XP/M-Audio2496) and wanted to track bass guitar to my Tascam 38 with it synced to the computer. My plan was to leave the drums in ACID and just have the computer slave to the SMPTE code (via JLCooper PPS2 30FPS Non-drop, MTC to the midi in on the M-Audio).

I striped track 8 with SMPTE from the PPS2 (30F/S Non-drop and VU meter was at 0). Then I sent the SMPTE to the PPS2 converting it to MTC. MTC via Midi in on the M-audio card, ACID set up to trigger to Midi TimeCode.

When I played the tape, ACID started playing along and all seemed right in the world. I tracked bass to tape (playing along with the sync'd drum track) and it felt pretty good. When I listened back the groove between bass and drums felt good but not quite "in the pocket". It felt like I pushed and pulled a bit (phrase by phrase but not note by note). So I tracked it again and listened back... Same thing. I kept redoing the bass part over and over until finally noticed one phrase that had felt perfect when I tracked it was really off on playback. So, I dumped the drumtrack to tape and tracked bass to tape without the computer involved and the groove was rock solid.

SO MY QUESTION: I realise that MTC will allow flanging like drift but this was much worse than that. Has anyone experienced this before? What did I do wrong? Any hints/fixes?

I'll post this same question to the Sonic Foundry/Sony/Acid forum (if it still exists) and see what turns up there as well.

Thanks

[linus]

Just one other thing to mention. Has anyone else heard this?

I heard that ACID Pro 3 does not truely sync to midi time clock, just that it starts at the correct frame based on the incoming signal then freewheels independantly until the MTC stops (then it stops).

Although this would explain what I heard, this is STUPID. I have a hard time believing that this is true. If this were true it would be an INCREDIBLE shortcoming of ACID.

Help Please...

[mrc]

Hi,
I had the same problem with a fosex 8 track, and adat, with cakewalk 3 and the pps2. Sync did work with my Tascam 644, its onboard sync and a Boss Drum Machine.
Since you have Acid 3, Acid 5 is out for $149.00 up grade (from any version), and now tracks audio, does vst effects and instruments, has more and better midi features and does rewire. I have had Cubase for my main program since 3.5, and have had Acid since version 2. I bought an MTPAV to sync the adat to cubase via adat sync, but cubase didn't work with that until 3.65, even then it was dodgy, and finally just gave up on that, Now using the adat now for a secondary set of input converters behind an AI3. The pps2, 4 and 8 track are in the closet museum. The Computer is just fine with 24 bit converters and a good front end. There are plenty of plugs that will dirty up the sound, as well as tube pres. I have completely dropped the flag for tape. Hard Drives are so cheap, and the newer computers so powerful, any tape less than 2 inch is probably a waste of time. A roll of 2 inch costs as much as several hard drives, so there you are.
Good Luck,
mrc

[linus]

MRC,

Have you heard that ACID 5 fixes this problem? I don't want to spend the cash for an upgrade just to have the same problem.

[mrc]

linus,
Can't say that I have. What I was trying to say was that the pps2 and tape are the culprits. I doubt anything is really going to give you tight sync, below some really high end sync units and 2 inch decks.....and even that may be dodgy at times. I was saying that I just gave up on that whole bit and went all computer. IMHO it's all that makes any sense for most of us. On the other hand some of the complete daw hardware units can be more intitive and simpler to use, though limited in options. If you need midi and want a lot of flexability, computer daws make a lot of sense.
mrc

[apropos of nothing]

I would burn your tracks out of Acid into wav files and then use a sequencer/DAW with a reliable synch to play them.

[linus]

So I got an answer from the folks at Sony on the Sonic Foundry/Sony forum.

It turns out ACID is incapable of syncing to an external MTC. It just triggers to the presence of MTC at the correct frame and then freewheels until MTC disappears then it turns off.

In other words if I start my reel to reel with the MTC generated for that moment 00:00:30:00 (30 seconds for example) then ACID will start playing the ACID file at the corresponding frame at 30 seconds. But it will freewheel the whole time until I turn off the reel to reel (MTC disappears) and then ACID stops playing.

So ACID will be fine if I'm just adding in synth pad sounds (or other sounds with no defined percussive attacks) but won't work if I am trying to add anything with percussive attack (It won't be close enough matched to groove).

[linus]

linus,
Can't say that I have. What I was trying to say was that the pps2 and tape are the culprits. mrc

Hey MRC,

See my previous post. It turns out that ACID is the culprit and that upgrading to ACID Pro 5 won't help. Just thought you'd want to know.

However burning the files to .wav and then syncing them out of Cubase would probably work better.

[mrc]

Hi,
The best lock would be bounce the tracks from acid to tape, then they are locked, or burn them out as files, load into cubase, now that we know you have it, and just forget the tape machine. With good converters, Cubase is FAR superior to your Tascam.
mrc

[linus]

Here is the reply that the Sonic Foundry/Sony guys gave me when I asked if they would be addressing the inability of ACID to sync to tape:

In order to achieve a true slave/sync, ACID would have to resample on the fly. This will effect the quality of the audio.

We chose a trigger only mode based on the assumption that the master device would be a digital device and have common digitial clock capabilities.

Yes, this is a broad assumption, but one that prevents us from going down the slippery slope of resampling the output of ACID on the fly to a non-sample accurate clocks source such as SMPTE/MTC.

I will just have to dump things into Cubase or Nuendo and work from there.

[mrc]

Seems like you had the answer all along, but now may be a good time to sell the tape machine: http://forum.nuendo.com/forum/Forum3/HTML/007350.html

[Mr. Dipity]

does rewire.

Slave, or just master?

Slave would be worth the upgrade cost, to me.

[mrc]

ReWire Mixer and Device Support
ACID Pro software works as both a ReWire mixer/host and a device/instrument. Use ACID software as part of your synchronized workflow with compatible applications such as Sonar?, Nuendo?, Cubase? SX, Live?, or Pro Tools? software.
http://mediasoftware.sonypictures.com/p ... ureID=7951

[Phalaris]

This is most likely because of wow and flutter and your computers inability to varispeed samplerate. In sync you need two things:

1. Positional Clock - what time is it?
2. Speed Clock - how fast are we going to count?

examples would be multiple machines all referencing a house video sync black burst and then choose ones SMPTE to be master. I think some time pieces will varispeed according to incoming SMPTE which has a bit of a speed clock because it is a digital 80Bit word, but MIDI TC I think takes 2frames time to tell a midi interface 1frame of info.