audio midi sync drift

Cubase
#1

I am starting a new project, and am having problems with sync on playback. I use cubase studio 4 and presonus firestudio 26x26 on windows XP machine. This setup has worked fine in the past.

Did some test recording of guitar over cubase click track and also some EZDFH (vst) midi drum loops. The problem seems to be audio-MIDI sync. The audio and midi drift after about 8 bars or so.

While recording, my playing is in time with either the click or the midi drum loops. On playback however, the guitar starts off in sync, and then usually ends up ahead of the midi. Also, the click track and the midi drum loop do not sync either. They are off from the very beginning of playback. I have tried multiple sample rates, buffer sizes, external sync via SPDIF mic preamp, different timecode control within cubase (internal, ASIO) and all have same problems.

I also have an M audio midisport 2x2 connected to the computer via USB. this is a new addition since the last time I recorded. It was on but but not being actively used (no midi coming in or out of computer) during the test recordings. not sure if that could be an issue.

#2

Not at my machine right now but I think there’s a preferences option to “Use System Timestamp”. I believe I’ve read about this fixing MIDI to audio timing problems.

#3

I looked through all available menus and didnt see anything about “use system timestamp”. I have cubase 4 studio. are you sure this is an option in 4? If not, is there a comparable option in 4?

Also, I notice that the “ASIO time overload” meter on the transport panel occasionally lights red. What is that meter? Could that be a problem? Sounds like it may relate to my problem. The regular ASIO usage meter is barely getting above 15% in this particular song. Project is brand new, and not a whole lot going on yet. The CPU and the presonus firestudio should not be even close to being overutilized. I even rendered the EZDFH track and then unloaded the vst. ASIO meter is way low, but the ASIO time overload meter on the top left of the transport stil “clips” regularly in this project.

#4

I know it’s there in Cubase 4.52I dont know about Cubase studio 4. Also not sure about the “Asio Time Overload” thing you mention. In 4.52, there are two meters that can be displayed in the transport bar. One is ASIO performance, the other , as I recall, is CPU performance.

If I understand it correctly, the ASIO performance meter kid of summarizes how hard the ASIO driver is working to deliver audio to the hardware (not sure if this a precise description)…In my experience, if you’re see’ing ASIO overloads when trying to playback audio (could be recorded audio or streaming samples) it’s due to insufficiant data transfer rates from the hard drives or not enough proc power in the system.

Could you provide more specific info on your system? What cpu/speed/amount of memory, number of hard drives and type etc…? Have you contacted Steinberg tech support?

#5

Device Setup- MIDI port config is where you find Timestamp. This is needed for Presonus kit. Emulated ports are required for the MIDISport, if you use that.

#6

thanks for the replies all. Found the time stamp thingy. checked both the windows midi and direct music. this doesnt appear to be the main problem, although its good info.

I dont think my problem is actually drift on playback. its sample loss during recording due to the ASIO time overload thing. I turned on ASIO warnings in preferences, and then did some testing. During basic playback of just very simple song (2 mono audio tracks, 1 stereo, and 1 midi vst), the song would stop with the error message: ASIO overload/audio drop out. Muted the midi track/vst and it still did it.


I did some audio over audio recording, to take MIDI completely out of the equation. no click track or anything. During recording, my playing was in time to the audio track I was playing over. when I played back these tracks together, they became out of sync, over time. Started out perfectly in sync, but by the end of the 2.5 minute jam, they were probably a quarter note out of sync, at 135 bpm. Does audio drop out mean I am actually losing audio data while recording?

I installed the latest presonus drivers, which helped a little. I now find that buffer size can basically eliminate the ASIO time overload clip, when playing back just the audio tracks at 256 or higher. But this is crap. I used to record audio with a 128 buffer with multiple vsts playing back at the same time, with no drift, on the exact same rig (but before new driver install and some other minor changes). I think the original drivers/firmware that came with the firestudio in 2007 are better than the ones out now…

any thoughts on all this?

#7

Did you re-start Cubase after checking the box? That audio is out too is strange. Are you sure you’re not monitoring different sources between record and playback?

#8

yes I did restart cubase after checking the timestamp boxes. during playback, the ASIO time overload meter still clips, and the 2 audio tracks in question are still go out of sync with each other. This is of course built into the original recordings, and wont change simply by checking some boxes. Having tried any new test recording yet. Ill do some test recording tonight and see if those boxes might have fixed the audio to audio sync problem.

for that particular test, I was monitoring audio playback through my monitors, and monitoring my recorded signal by being in the room with my amp. obviously no latency when monitoring by listening to the amp itself. also, if monitoring setup was the problem, the 2 tracks would be out of sync from the beginning, and would be off by a constant amount. in my case, they start off in sync, then fall apart. the longer the uninterrupted recorded track is, the further it gets out of sync. short takes do not become noticably out of sync. this tells me its some sort of data loss during recording. if a clip is short and you only lose a few samples, it might not be noticable. over a long take, you lose many more samples, and therefore by the end of the take you are way off.

sound right? I think it all goes back to the ASIO time overload thing. increasing buffer size seems to help this, but I still want to know what the real problem is. I really hate workarounds. This crap is supposed to work. This rig used to work quite well, and could handle multiple vsts and low buffer sizes during monitoring and playback. now it craps its pants when I try to monitor 3 audio tracks while recording with a 128 buffer.

some details on the system: xp machine with 2G ram, AMD athlon 64 2.2 ghz, presonus firestudio, cubase studio 4. not sure about the HD, but its the same HD as ever. All the gear is exactly the same. The only thing that changed since it used to work well is this: had to send in the firestudio to presonus cuz it lost its firmware. when I got it back, it was with updated firmware and a new version of the drivers and VSL interface. I believe I reinstalled cubase as well, from the original disk. Also had to update the stupid elicenser thingy.