Audio & MIDI Synchronization with M-Audio Delta Interfaces

Hello everyone.
 
I've searched around for answers to this and while I've found a solution, I haven't found out why it's happening or what you can do about it.  I've been using Pro8.5 & it also appears in X1.  I've not tried X2 yet but judging from the link below, it still happens.  I can't try X3 as I'm not licenced for that just yet!
 
Basically, if I record/bounce MIDI to audio, be it internally from a VSTi or an externally recorded synth, when I play it back, the audio plays slightly ahead of any other MIDI instruments whether they are a VSTi or other external hardware synths!
 
Now, I've absolutely no latency problems with my soundcard or dropouts, etc, as all my MIDI VSTi's & external synths all play in time with each other so that's not it!
 
Also, all the MIDI data has been quantised and as I've said, that's not the problem as that all syncs up and sounds on beat so I know my interfaces are working fine.
 
What I've discovered is if I use the "Timing Offset" setting and specify a delay of about 40ms, everything plays in time without any drift either!  If I don't adjust this setting, ie, I leave it with no offset, then when playing back the recorded audio with the original MIDI file outputting to a VSTi or hardware synth, there's a fraction delay going on which is perceivable as you hear the recorded track fractionally before the MIDI sounds.
 
I hope this is making sense.
 
Does anyone have anything to add?  Have I missed something during the set-up phase?
 
Just for the record, I've run the wave profiler and my soundcard buffers are at 2 and audio latency settings are at about 11ms which I've lowered as I'm not getting any problems.
 
The solution to the problem is here: http://www.cakewalk.com/Documentation/default.aspx?Doc=SONAR%20X2&Lang=EN&Req=Dialogs2.056.html
 
I'd really like to know why this is happening and whether anything can be done about it.
 
Many thanks for any input.

There is a trial version of X3 available for those needing a version for testing.

If it is a record latency compensation issue, existing recordings won't be affected by the change to ASIO. You'll need to do some testing with a new project or new recordings in an existing project to see if it makes any difference.
 
But if you have multiple interfaces using different drivers, you would have to stay with WDM to have access to both. If they use the same driver, I think you should be able to switch to ASIO and still have access to I/O on both interfaces, but I'm not sure about that.

I think you'll find that most manufacturers, including M-Audio, recommend using ASIO if the host supports it. An ASIo buffer of 128 samples is low enough not to be bothersome when recording hardware but high enough to accommodate most projects. If it's too low, you'll start to hear get pops and crackles on playback from dropped buffers.
 
Automatic latency compensation should have compensated for whatever latency was in effect at the time, whether using ASIO or WDM drivers, but if something was wrong and audio was not compensated properly in some projects, manually compensating those recordings as needed is really the only solution.

DPC latency is a measure of how fast your CPU can respond to a streaming request from SONAR. Under 200 microseconds is reasonable, but not stellar - mine is in that same range. A lot depends on the quality of the interface and its drivers; the Delta's a pretty old card, so I'm not sure how well it handles very small buffers, but you can certainly try 64 or even 32 samples and see how it goes.
 
The Cori Yarckin and Javier Colon demos that came out with X2 and X3, respectively, make good performance benchmarks. With all synths and FX unfrozen, I have to run a 256-sample buffer on my old Quad Core to get smooth playback with either of those. I do pretty much everything else at 128, and can go to 64 in very light projects. Whatever buffer you are able to run those projects at, you can probably comfortably go to half that for everyday work, assuming your average project is not that complex, and maybe a quarter when you want the lowest possible latency for tracking.
 
As you say, lower is better if the machine can handle it, but at a certain point, your CPU will working hard enough even at idle that you'll just be wasting energy, generating a lot of heat, and causing your fans to make more noise.
 
Click the ASIO Panel button on the Driver Settings page to get access to the buffer setting, which is your main latency control. The Manual Offset is for entering a value to dial in your Record Latency Compensation in conjunction with the automatic compensation to get sample-accurate compensation of the clip position for the Input latency. This happens after recording is stopped, and doesn't affect the realtime latency. Download the free Centrance Latency checker to measure the actual round-trip latency and determine what the Manual Offset needs to be (Centrance measured value - SONAR reported value).