Dan_E10
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How to keep outboard synths and VST's in sync?
Hi all,
I'm have a modular analog synth that I'm using to supplement soft synths. I've noticed that when playing the modular from midi tracks in Sonar X3, it plays just slightly after vst's. When I record the modular to an audio track, delay compensation works correctly and the recorded audio clip lines up perfectly. However, it gets to be a pain to have to bounce tracks to get them to line up with the vst's when I'm still in the process of editing the midi tracks.
It seems that for the most part the midi offset delay in preferences works well to get the outboard synth to line up with the vst's during playback. However, I've noticed that if I switch projects, the offset that worked for the first project now doesn't work at all for the second project. The modular is again out of sync with the vst's. I've found that the delay I need to add also varies with the ASIO buffer used. Reducing the ASIO buffer to the minimum (2 ms) helps somewhat, but it's still not perfect and I get more drop outs at that setting.
From reading other threads here such as the midi jitter thread, I'm guessing this is one of those complicated "many links in the chain" problems where midi and audio drivers as well as the OS all affect the outcome. Anyway, I'm wondering if anyone here has some tips on how they keep their outboard and virtual synths in sync. Does it usually just work, or do you have to do some testing with each project/session to determine the midi delay you need to use?
I'm on Win 7 64 bit using an old Emu 1820M by the way. The 1820M only has beta drivers available for Win7, but they work for me more or less. I don't have an external clock, the 1820M is providing all timing. Sometimes I do feel like the midi clock drifts slightly from the audio clock as well, but this isn't repeatable for me.
Dan
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lfm
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 08:55:02
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I use Metaplugin for that - making a general movement of a synth as I calculated it needs to line up. http://ddmf.eu Among the best $50 I spent, apart from Sonar Artist. What I do is let the gui be as default, all audio just run through. Then set the field for latency to whatever samples you need to report to host. As I remember it's about 350 samples for my Hammond. So setting this Metaplugin on a track your report 350 samples, but no such delay is performed. Meaning a recorded clip will be put 350 samples early by host. I usually render external instruments early, after recorded - not having to keep external gear on while finalizing it all. EDIT: Forgot about the Time+ field on midi tracks. There you can adjust to make audio for that track to line up. So much simpler in Sonar than many hosts.
post edited by lfm - 2015/04/15 10:22:21
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tlw
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 09:23:24
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I generally find things "just work", or very nearly. How far out is the audio compared to the MIDI?
Hardware synths take differing amounts of time to respond to MIDI, so I might need to slightly nudge audio to get spot-on agreement with the MIDI source track but it's a very few milliseconds at most and usually just a few samples.
I run at a 48 sample audio buffer and use Sonar's track echo function for monitoring by the way. That's around a 5ms round trip for the audio.
Things that might mean sync varies between projects include using plugins at the tracking stage that require plugin delay compensation. That's generally anything with a look ahead function and convolution reverbs. Another issue might be if you are daisy-chaining hardware using MIDI thrus. As each thru will delay the MIDI a little and MIDI is a serial protocol so data intended to each synth in the chain will get sent to one synth then the next etc. that can also affect MIDI timing. Finally, no MIDI clock is perfectly stable and like any MIDI application in Windows, Sonar's clock does wander a little.
If the MIDI sync is consistently out there's a setting in preferences you can adjust to have Sonar automatically compensate. In my case it's not much use as I have several synths connected each of which has a slightly different MIDI processing time plus I've two MIDI interfaces which also slightly differ in processing time.
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dcumpian
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 10:15:19
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Can't say I've ever noticed any variance between the timing of VSTi's and external synths while playing back midi tracks. Something doesn't sound like it is working correctly. See if you can borrow another midi interface and see if that tightens up your timing with the VSTi's. Not all midi interfaces work well, particularly if it is an afterthought to an audio interface.
Regards,
Dan
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John
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 10:18:38
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I use VSTis and hardware synths routinely and can't say there has ever been any sync problems. It just works.
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bitflipper
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 10:23:23
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It sounds as though your problem might be that you're monitoring the synth through SONAR, where the lag between generating a MIDI note on your controller and the synthesizer responding is going to be variable due to different latencies in different projects.
If that's it, then the solution is to monitor your synthesizer in real time. Most audio interfaces feature a so-called "zero-latency" monitoring mode, wherein its analog input channels are routed directly to the interface's output or headphone outputs. Check your interface's documentation.
 All else is in doubt, so this is the truth I cling to. My Stuff
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 10:53:14
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The 1820m has very low MIDI transmission delay compared to most USB interfaces, so assuming the synth has a decent response time (usually no more than a few milliseconds for modern hardware), any sync issue should be mostly due to audio latency. The Timing Offset can be used to address this, but can have undesirable side-effects since MIDI grid is offset for recording as well as playback. Ideally you should just keep your ASIO buffer as low as possible, and it shouldn't be a significant problem.
With ASIO buffer at 2ms, the RTL will be under 6ms and the MIDI transmission/response time will be adding maybe 5ms to that. Soft synths will be subject to the same outbound audio latency, so the discrepancy should only be on the order of 8ms, which is more on the order of a large phase error than a timing error. Bumping the ASIO buffer to 3-4ms would only add another 1-2ms to the discrepancy.
if the timing is really audibly off, then something else is going on like PDC. If you're using FX plugins that require PDC, you'll need to enable the PDC Override for live inputs so the hardware synths aren't affected. This really the only thing I can think of that would account for differences between projects too.
I loved the performance, flexibility and sound of the 1820m, but I had pretty significant problems with the beta x64 drivers.
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 11:21:57
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tlw
I generally find things "just work", or very nearly. How far out is the audio compared to the MIDI?
I seem to need to use a timing offset of between 0 and 80 ms in the "Full Chase Lock" synchronization setting. It varies by project and also by ASIO buffer size. The minimum buffer I can choose is 2 ms but I need to use about 8 ms to avoid pops and crackles in the audio. tlwHardware synths take differing amounts of time to respond to MIDI, so I might need to slightly nudge audio to get spot-on agreement with the MIDI source track but it's a very few milliseconds at most and usually just a few samples.
I run at a 48 sample audio buffer and use Sonar's track echo function for monitoring by the way. That's around a 5ms round trip for the audio.
Things that might mean sync varies between projects include using plugins at the tracking stage that require plugin delay compensation. That's generally anything with a look ahead function and convolution reverbs. Another issue might be if you are daisy-chaining hardware using MIDI thrus. As each thru will delay the MIDI a little and MIDI is a serial protocol so data intended to each synth in the chain will get sent to one synth then the next etc. that can also affect MIDI timing. Finally, no MIDI clock is perfectly stable and like any MIDI application in Windows, Sonar's clock does wander a little. The plugins used in one of my test projects were the Sonitus delay and BreVerb. Perhaps things were not equals between the tracks used for the outboard synth and the soft synths. I am not needing to chain multiple midi thru's yet, but I will soon. I'm sending midi out to a midi-CV converter which is monophonic. I plan to add a couple more channels with a second midi-CV converter so I'm hoping that doesn't add some more sync headaches. thanks, Dan
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 11:26:27
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bitflipper
It sounds as though your problem might be that you're monitoring the synth through SONAR, where the lag between generating a MIDI note on your controller and the synthesizer responding is going to be variable due to different latencies in different projects.
If that's it, then the solution is to monitor your synthesizer in real time. Most audio interfaces feature a so-called "zero-latency" monitoring mode, wherein its analog input channels are routed directly to the interface's output or headphone outputs. Check your interface's documentation.
Thanks bitflipper. I am monitoring through Sonar. I'm kind of stuck doing this since I'm using delay and effects a lot at the composition stage. A zero-delay monitoring mode would bypass all fx applied in Sonar correct? The midi tracks I'm working with right now have been input with the staff view and PRV so any midi controller contributions to the sync shouldn't be a factor I'm hoping. Dan
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 11:29:28
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lfm
EDIT: Forgot about the Time+ field on midi tracks. There you can adjust to make audio for that track to line up. So much simpler in Sonar than many hosts.
I wasn't even aware of this! This may be a much easier to use option than the timing offset field I've been modifying in preferences. I'll have to try this. Thanks! Dan
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 11:33:14
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brundlefly
The 1820m has very low MIDI transmission delay compared to most USB interfaces, so assuming the synth has a decent response time (usually no more than a few milliseconds for modern hardware), any sync issue should be mostly due to audio latency. The Timing Offset can be used to address this, but can have undesirable side-effects since MIDI grid is offset for recording as well as playback. Ideally you should just keep your ASIO buffer as low as possible, and it shouldn't be a significant problem.
With ASIO buffer at 2ms, the RTL will be under 6ms and the MIDI transmission/response time will be adding maybe 5ms to that. Soft synths will be subject to the same outbound audio latency, so the discrepancy should only be on the order of 8ms, which is more on the order of a large phase error than a timing error. Bumping the ASIO buffer to 3-4ms would only add another 1-2ms to the discrepancy.
Reducing the buffer to 2ms does help, but doesn't completely eliminate the problem. brundleflyif the timing is really audibly off, then something else is going on like PDC. If you're using FX plugins that require PDC, you'll need to enable the PDC Override for live inputs so the hardware synths aren't affected. This really the only thing I can think of that would account for differences between projects too.
I loved the performance, flexibility and sound of the 1820m, but I had pretty significant problems with the beta x64 drivers.
I was assuming PDC wasn't a factor since I wasn't using convolution reverbs but maybe that's not the case. I will try the PDC override you mention to see if it makes a difference here. thanks everyone! Dan
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 11:58:22
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If you disable record latency compensation and record the hardware synth driven by existing MIDI and playing a patch with a fast attack, how late are the audio transients relative to the MIDI events in milliseconds with the ASIO buffer at 2ms? And what synth is it, exactly?
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bitflipper
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 12:08:13
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Dan_E10
bitflipper
It sounds as though your problem might be that you're monitoring the synth through SONAR, where the lag between generating a MIDI note on your controller and the synthesizer responding is going to be variable due to different latencies in different projects.
If that's it, then the solution is to monitor your synthesizer in real time. Most audio interfaces feature a so-called "zero-latency" monitoring mode, wherein its analog input channels are routed directly to the interface's output or headphone outputs. Check your interface's documentation.
Thanks bitflipper. I am monitoring through Sonar. I'm kind of stuck doing this since I'm using delay and effects a lot at the composition stage. A zero-delay monitoring mode would bypass all fx applied in Sonar correct? The midi tracks I'm working with right now have been input with the staff view and PRV so any midi controller contributions to the sync shouldn't be a factor I'm hoping.
Dan
True, that's the downside of zero-latency monitoring. However, many audio interfaces have an effects loop for inserting hardware effects, allowing you to hear them without actually recording them. Because they're not being recorded, you can get away with cheap second-hand delays and reverbs that can be found on Craigslist or eBay for $40-50. Then you'll have the best of both worlds. If that's not an option, consider printing your delays live, old-school. I use this fairly inexpensive unit for that purpose. It's stereo and emulates dozens of different classic devices, including delays, reverbs, chorus, flangers and tremolo.
All else is in doubt, so this is the truth I cling to. My Stuff
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 12:14:27
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The 1820m has onboard FX that could be used for direct-monitoring with a delay. But I still think the OP should be able to get this ironed out such that input monitoring doesn't add intolerable - or even noticeable - latency. Something's funky in the setup.
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 13:03:33
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brundlefly
If you disable record latency compensation and record the hardware synth driven by existing MIDI and playing a patch with a fast attack, how late are the audio transients relative to the MIDI events in milliseconds with the ASIO buffer at 2ms? And what synth is it, exactly?
I will try this. The synth is a synthesizers.com modular analog. It doesn't have a midi interface, only control voltage inputs on most of the modules. I'm using a Kenton Solo II midi - CV converter to drive it. I send midi from Emu's first output port to the Kenton and then wire up patch cables from the Kenton for pitch, velocity, and gate signals used by the modular. I'm assuming (hoping) the latency of the midi-CV converter to be constant. Dan
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 13:23:51
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Hmmm... could definitely be some extra latency in that chain. I did a quick check of the Kenton's documentation and didn't see any reference to latency, which is a little surprising and suggests they might not wan't to talk about it. Your test results should tell the tale. EDIT: I found synthesizers.com's own MIDI-CV converter promises latency < 1.5ms, which is very reasonable, but it's not clear how fast the synth responds in turn.
post edited by brundlefly - 2015/04/15 13:35:13
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tlw
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 18:43:07
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I would have thought response to CV would be pretty much instant, with the MIDI-CV conversion taking up much more time unless the synthesizers.com envelope triggers aren't very quick or are slightly delayed to avoid clicks and pops if the attack is set to zero. Even so 80ms is one heck of a MIDI timing error for anything, never mind the kind of quality that synthesizers.com are known for.
I've a real mix of synths, a mix of digital and analogue with MIDI+CV control, hooked up via MIDI either to a MOTU MIDI interface, the UFX MIDI ports or directly connected via USB plus AD2, Session Drummer and DimPro and my out-of-sync problems against are in the order of a few milliseconds. Small enough to be inaudible. Sonar's transmitted MIDI clock does wander a little (or so my MachineDrum claims) but not enough to notice unless I'm looking at the MDs tempo display. I can monitor through Sonar while putting delays and modulations on stuff without any problems at all with an audio buffer of 48 or 64 samples. Though RME drivers and hardware are particularly food for low latency performance my old UA-101 could manage around 10ms round trips without problems.
I suspect MIDI discrepencies in the order of 80ms has something to do with plugin-induced latency somewhere. Or possibly something about the specific modular patch....
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/15 22:27:53
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brundlefly
If you disable record latency compensation and record the hardware synth driven by existing MIDI and playing a patch with a fast attack, how late are the audio transients relative to the MIDI events in milliseconds with the ASIO buffer at 2ms?
Assuming I correctly disabled record latency compensation and am measuring the delay accurately, it looks to be a total latency of 6.9 - 7 ms for an ASIO buffer of 2 ms. The frustrating thing is that tonight, the sync between the outboard synth and the soft synth I'm using is much better. Still, I was able to hear a slight difference between the virtual and outboard synth when playing 8th notes with sounds set to very fast transients. After playing around with the Time + field at higher latencies I was able to get the virtual and outboard synths to align fairly easily. At the 2 ms ASIO buffer, I could not hear a difference in the timing of the virtual and outboard synths. Can anyone tell me what the units of adjustment of the Time + field are for a midi track? Are they ticks? thanks, Dan
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lfm
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Re: How to keep outboard synths and VST's in sync?
2015/04/16 02:36:22
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Dan_E10
Can anyone tell me what the units of adjustment of the Time + field are for a midi track? Are they ticks?
thanks,
Dan
As I remember it's ticks.
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/16 09:54:42
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That makes sense, thanks.
So far I'm ready to chalk my problems up to PDC as well as attempting to use diferent ASIO buffers. From my testing so far, I definitely need a larger time offset on the midi tracks to keep things in sync as the ASIO buffer goes up. I guess that makes sense as the round trip latency on the outboard synth increases at double the rate of the softsynths if I'm understanding it correctly. Double the ASIO buffer results in double the latency for softsynths, but 4x the latency for monitored signals. The Time+ field seems to work a lot better than changing the time offset in preferences since it only affects the desired midi channel. My midi-CV converter doesn't seem to be a large contributor to the overall latency, adding about 3 ms.
From this point forward, I'm going to stop worrying about this and just make some Time+ adjustments or turn on PDC overrride if things start to sound out of sync.
thanks everyone,
Dan
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/16 11:13:54
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Dan_E10
I guess that makes sense as the round trip latency on the outboard synth increases at double the rate of the softsynths if I'm understanding it correctly. Double the ASIO buffer results in double the latency for softsynths, but 4x the latency for monitored signals.
Actually the factor is a little less than 2x for both because there's a fixed component of both input and output latency that doesn't change. And the discrepancy only increases by the absolute change in buffer size. For example, at a buffer of 4ms, your round trip is about 10ms with 2ms for A/D/A conversion and PCI bus latency, and half of that, 5ms, is output latency to which soft synths are subject. If you double your buffer to 8ms, your RTL goes to 8+8+2= 18, and outbound is 9ms. So soft synth latency is up by 9/5 = 1.8x, and RTL is up by 18/10 = 1.8x. But the change in the discrepancy is just the change in the buffer size, 8-4 = 4ms; the discrepancy (not including MIDI) was 10-5 = 5, and is now 18-9 = 5+4 = 9ms. In any case, I agree that the really heinous error you reported initially would have had to be due to PDC. The garden-variety discrepancy you've measured shouldn't be a problem at lower buffer sizes where you need to be for the tracking phase of a project, anyway. And with an apparent MIDI transmission/response delay of only 4ms, even at that 8ms buffer size, a discrepancy of 9+4 = 13ms shouldn't be a problem while tracking, and will be mostly corrected by record latency compensation when you finally record the outboard synth. Clear as mud? 
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/16 12:02:16
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Haha, thanks for the correction brundlefly. Yes that makes sense, I wasn't thinking it through clearly. What I probably should have written is just that the discrepancy increases as the buffer increases. Before getting into this problem, I was assuming that increasing the ASIO buffer would just delay everything together. It took me be surprise when I increased the buffer to eliminate some clicks and pops from soft synths and then the hardware synth was not in sync with the rest of the project. This makes me wonder if there's a better way to compensate this. It seems like something like an "outboard synth" instrument track with automatic round trip delay compensation might be nice feature to have to avoid having to manually measure and adjust the Time+ field for midi tracks associated with outboard instruments. I guess record latency compensation does this pretty well, but it would be nice to have on the playback side for cases where you aren't ready to bounce tracks yet and can't use a small ASIO buffer. Dan
post edited by Dan_E10 - 2015/04/16 12:23:52
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/16 13:02:46
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I've often thought it would be nice to have per-input latency compensation and a way to link MIDI tracks with audio track for external synths as is done for soft synths. I know some other DAWs do the latter and I even entered a formal feature request for the former to address the difference between digital and analog input latency. But it's never really been enough of an issue for me to really push for it. In fact, I rather like the "airyness" that results from having slightly different delays on layered hardware synths.
Ultimately, I prefer the KISS approach of just keeping the ASIO buffer as low as possible, and not worrying about any timing discrepancies that I can't readily hear with the "naked ear" (i.e. unassisted by zooming the timeline to see alignment errors), or that aren't unpleasant. And by the time PDC-inducing plugins are being added to the project, the synth audio should already have been recorded.
But if I really wanted to address it in a particular project, I think I would try routing all the ITB audio tracks to a "Compensation Delay" bus and adding an appropriately configured delay plugin (i.e. 100% wet) to the bus, rather than trying to compensate individual tracks one way or the other.
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/20 09:24:01
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After some more testing with this it feels like two steps forward and one step back. Working with an ASIO buffer of 14 ms to avoid pops and clicks from the softsynth end of things, I measured a delay of about 17 - 21 ms between the midi notes and the recorded track. Using a midi grid of 960 ticks per quarter and a tempo of 120 bpm, I get a time+ value of about -33 to -40 ticks needed to line up the audio with the desired note on times. However, using this time+ value does not get the outboard synth to completely line up with the softsynths during playback. I need to use something closer to the total round trip delay to get things to sound like they're lined up. Doing this makes playing the outboard synth live from the compensated midi track sound like the bounced track with record latency compensation turned on (and no time+ offset).
This makes me wonder if Sonar is doing some kind of delay compensation automatically on the soft synths even though I have PDC override on. I would have thought I'd only need to compensate for the record and midi latency but not the playback latency as I thought that the softsynths would be subject to the playback latency as well. If not, so be it as long as it's consistent. I will have to play around with this some more unfortunately because after closing the project to work on some other projects, and then reopening it, sync between the outboard synth and the softsynths seems slightly off again. The strange thing is that bouncing the track to audio with record latency compensation on seems to consistenly result in a track that lines up subjectively with the softsynths. However live playback of the midi track while monitoring the outboard synth seems to give slightly different results each time. After updating to the X3e patch, I found I could run lower latencies without clicks and pops so hopefully a lot of these headaches just go away.
Dan
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lfm
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Re: How to keep outboard synths and VST's in sync?
2015/04/20 10:00:57
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Dan_E10
....and then reopening it, sync between the outboard synth and the softsynths seems slightly off again.
What do you mean in terms of ms or samples - how much is it? I made some experiments thinking now I should make this line up in a perfect way. So I rendered external synths one time, and got one result, another time and got another result. Then I came to think of that deviation was within the period length of the sound produced by the note I used as reference. What was noise, and which little cruising on audio should be reference and line up? A normal A - 440Hz - period length 2.3ms - 110 samples at 48k. Is it 82 Hz, like open 6th string on guitar - 12ms - 576 samples. Is it a bass note an octave down form that - 24ms - 1152 samples. So what do I use as reference - the start of the waveform to align with grid? And how do an external synth generate a note sound? How long is attack time of that sounds ADSR - also matters when you actually see part of a waveform to align with the midi you see on grid? So what is the delay of synth to respond - and what is part of patch you are playing? A fade in of 10-15ms is common to work as non-pop sound to arrive. The external synth has it's oscillators running(seems to on my Hammond anyway emulating free running tonewheels) - and a midi note arrives. It can be different which part of waveform you see first. So trying to get sample accurate alignment might not be possible, and you have to adjust depending on synths and even patch used. But you should use a fast attack patch to get overall propagation delay for synth to respond.
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/20 10:23:27
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Hi lfm, thanks for the response. lfmWhat do you mean in terms of ms or samples - how much is it?
I'm measuring in milliseconds and then converting to ticks to determine what value to use in the time+ field. lfmI made some experiments thinking now I should make this line up in a perfect way.
So I rendered external synths one time, and got one result, another time and got another result.
.....
The external synth has it's oscillators running(seems to on my Hammond anyway emulating free running tonewheels) - and a midi note arrives. It can be different which part of waveform you see first.
So trying to get sample accurate alignment might not be possible, and you have to adjust depending on synths and even patch used.
But you should use a fast attack patch to get overall propagation delay for synth to respond.
Yes, I agree sample accuracy is not possible in this case. I'm just shooting for a tracking that sounds subjectively in groove with the softsynths. For testing this, I'm using a patch with a fast attack, the attack stage is set to minimum on the outboard synth, and a midi note somewhere around middle C. I realize there will be some variability when zooming in on the audio and midi tracks due to things like free running oscillators being in different spots at each note on. However, the inconsistency I'm experiencing here is larger than that. I'm actually hearing the track from the outboard synth sound slightly out of sync from the softsynths when played live and monitored through Sonar. This implies to me that it's more than a variability of a few msec. The weird thing is that every time I bounce the track using record latency compensation, I get something that sounds completely in sync with my softsynths. So it seems that Sonar is correctly using the reported ASIO latency to arrive at the bounced track. For some reason there seems to be some variability in the latency of the live monitored tracks during playback that is preventing me from using the time+ field to consistently remove it. As I stated above, I can set time+ to a value that makes the outboard synth subjectively sound in sync with the soft synths. Then later, after reopening the project the outboard synth no longer sounds in sync and I need to find some new value to use in time+ to get it to sound right. It looks like that last test I need to do is measure latency at the beginning of a session and then later at the end of the session to see if it's really changing all that much. Dan
post edited by Dan_E10 - 2015/04/20 10:33:10
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/20 12:07:04
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Dan_E10
Working with an ASIO buffer of 14 ms to avoid pops and clicks from the softsynth end of things, I measured a delay of about 17 - 21 ms between the midi notes and the recorded track.
First, I think you need to find a way to get your ASIO buffer down without getting pops and clicks. Your 1820m should be able to take just about anything you can throw at it with a buffer of no more than 6-8ms. Unless your projects are extremely plugin-heavy, you shouldn't be having to run a buffer much higher than that. And if you can't run a basic project with a few soft synths and FX in it at 2ms, you should start by downloading a free DPC Latency checker like DPCLAT or LatencyMon (Google them) and making sure you don't have high or variable/spiking DPC latency. Trying to compensate MIDI-Audio delays starting with a large ASIO buffer is bound to be a losing proposition, especially when using per-track time offsets in ticks that vary with tempo. As I said earlier, the best solution is just to get all the latencies down to a point that it's not bothersome and doesn't need to be corrected. You should be able to do that with anything resembling current PC hardware, although the fact that you're running a PCI-bus interface suggests your PC might not be state of the art (since most current mobos don't have PCI slots). What are your PC specs?
SONAR Platinum x64, 2x MOTU 2408/PCIe-424 (24-bit, 48kHz) Win10, I7-6700K @ 4.0GHz, 24GB DDR4, 2TB HDD, 32GB SSD Cache, GeForce GTX 750Ti, 2x 24" 16:10 IPS Monitors
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/20 12:52:16
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Hi brundlefly, Thanks for the response. brundleflyFirst, I think you need to find a way to get your ASIO buffer down without getting pops and clicks. Your 1820m should be able to take just about anything you can throw at it with a buffer of no more than 6-8ms. 8 msec was the value I set my 1820m's buffer to for the last few years. I've only recently started increasing it to 14 msec after upgrading to X3. It seemed X3 was heavier on the CPU in my case and required a larger buffer to avoid clicks/pops. Since I was running mainly midi tracks entered straight from either PRV, staff view, or step sequencer I figured low latency wasn't really a necessity. After wrestling with these sync issues, I can see that low latency would simplify things even when not playing synths live from a keyboard. After updating to X3e, I wasn't getting clicks and pops at 8 msec buffer so it looks like that may have been resolved. I'm keeping my fingers crossed on this, because my click/pop issues in X3 seem to go away temporarily whenever I reinstall drivers and then come back after a few days. Hopefully the X3e update has fixed this for good. brundleflyTrying to compensate MIDI-Audio delays starting with a large ASIO buffer is bound to be a losing proposition, especially when using per-track time offsets in ticks that vary with tempo.
As I said earlier, the best solution is just to get all the latencies down to a point that it's not bothersome and doesn't need to be corrected. You should be able to do that with anything resembling current PC hardware, although the fact that you're running a PCI-bus interface suggests your PC might not be state of the art (since most current mobos don't have PCI slots). What are your PC specs?
I built my computer in 2011. As I remember PCI slots were getting scarce even back then and I had to narrow down my motherboard search to find one that had them to keep using my 1820M. My PC specs are: Win7 64 bit Intel I5 2500 4 Gb ram Asrock motherboard P67 Extreme 4 Dan
post edited by Dan_E10 - 2015/04/20 13:01:29
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brundlefly
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Re: How to keep outboard synths and VST's in sync?
2015/04/20 13:54:17
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Definitely check your Deferred Procedure Call (DPC) latency - not to be confused with audio latency. This is measure of your CPU's responsiveness to requests to service the ASIO buffers; if it's too slow or highly variable, you get dropped buffers that cause the pops and clicks.
I had already retired the 1820m sometime before X2/X3, but based on my experience running it under everything from S6 to X1, I'd be very surprised if its performance were affected significantly by a change in the version of SONAR alone, though X3 did see some changes to the audio engine - mainly around the "Always Stream Audio Through FX" functionality vs. the old "Play FX Tails" option.
SONAR Platinum x64, 2x MOTU 2408/PCIe-424 (24-bit, 48kHz) Win10, I7-6700K @ 4.0GHz, 24GB DDR4, 2TB HDD, 32GB SSD Cache, GeForce GTX 750Ti, 2x 24" 16:10 IPS Monitors
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Dan_E10
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Re: How to keep outboard synths and VST's in sync?
2015/04/20 15:40:27
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I'll check the latency as you recommend and see if it looks like it's spiking. I had looked at the "Always Stream Audio Through FX" settings as some others on this forum reported getting dropouts after upgrading to X3 from X2. Unfortunately, it didn't have an effect in my situation.
Dan
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