getting MIDI/audio lag after using live for a while?

[sphinxxx]

I cannot find any pattern to this... it seems to happen at random for the most part. I never notice it when starting a new set, but after a while I notice it, even though it is subtle.

I'm getting a slight lag when playing midi notes. I don't know if its the MIDI that's lagging, or (more likely), the audio. My overall latency in Ableton's preferences is 17ms, and I'm using the Firepod audio interface via firewire to a firewire PCI card on my desktop.

My Sample rate is set to 48khz - could this be possibly causing problems when I have a lot of tracks going on simultaneously?

Is there anything I can do to pinpoint exactly what's going on here?

Thanks!

[Akshara]

Recording at 48khz shouldn't cause this type of problem on its own. Besides there being a problem with either the FirePod, the PCI card, or their drivers, three possibilities come to mind.

1) As the project develops, if audio is getting routed through busses and channels with live inputs, then it could be a plugin delay compensation issue, pushing the audio out of time with your playing. Live has an unusual way of handling latency, for live performance use, and does not compensate input channels as one would expect. The following thread sums up the issue (and links to the original discussion)... http://forum.ableton.com/viewtopic.php?f=1&t=163988

For the following, I am presuming you are on a PC Desktop.

2) There may be something interfering with the PCI Firewire card on the PCI bus, causing an intermittent delay, or latency jitter, in the audio/midi stream. On my PC desktop, the audio card must be in Slot 2, or the motherboard's bios will assign it to an IRQ with something else, which can cause all kinds of problems.

3) Besides PCI Latency, there is a thing called DPC Latency, which has been known to cause intermittent hiccups with audio. I used to run a tool called DPC Latency Checker and then optimized my system to keep everything in the green, by disabling WiFi, lowering the graphics card options, disabling unnecessary services, etc. Having switched to Mac a few years ago, I am out of the loop with current Windows optimizations, yet search around and I'm sure you will find some tips on how to lower the DPC Latency on your system.

Hope one of these points you in the right direction.

[sphinxxx]

Akshara, thanks so much for this info.

1) I downloaded the DPC tool and ran it for a few minutes. The absolute maximum was only 150 us. However I ran this by itself, not while ableton was running or playing audio through the interface.

2) The PCI card has 3 firewire ports, but only 1 is being used (by the firepod interface). Is it still possible the resource is being shared with something else? And if so, what should I be looking for?

3) I do often notice MIDI notes, upon playback, being slightly slightly different than how I remembered it while I was playing it. It is very slight, but I can just "feel" that something is off. I had just dismissed it before but now I am thinking I have some kind of compensation issue.

Recording at 48khz shouldn't cause this type of problem on its own. Besides there being a problem with either the FirePod, the PCI card, or their drivers, three possibilities come to mind.

1) As the project develops, if audio is getting routed through busses and channels with live inputs, then it could be a plugin delay compensation issue, pushing the audio out of time with your playing. Live has an unusual way of handling latency, for live performance use, and does not compensate input channels as one would expect. The following thread sums up the issue (and links to the original discussion)... http://forum.ableton.com/viewtopic.php?f=1&t=163988

For the following, I am presuming you are on a PC Desktop.

2) There may be something interfering with the PCI Firewire card on the PCI bus, causing an intermittent delay, or latency jitter, in the audio/midi stream. On my PC desktop, the audio card must be in Slot 2, or the motherboard's bios will assign it to an IRQ with something else, which can cause all kinds of problems.

3) Besides PCI Latency, there is a thing called DPC Latency, which has been known to cause intermittent hiccups with audio. I used to run a tool called DPC Latency Checker and then optimized my system to keep everything in the green, by disabling WiFi, lowering the graphics card options, disabling unnecessary services, etc. Having switched to Mac a few years ago, I am out of the loop with current Windows optimizations, yet search around and I'm sure you will find some tips on how to lower the DPC Latency on your system.

Hope one of these points you in the right direction.

[Akshara]

1) I downloaded the DPC tool and ran it for a few minutes. The absolute maximum was only 150 us. However I ran this by itself, not while ableton was running or playing audio through the interface.

Usually if there is a real problem, a spike will show up even when the DAW isn't running, so this probably is not the issue.

2) The PCI card has 3 firewire ports, but only 1 is being used (by the firepod interface). Is it still possible the resource is being shared with something else? And if so, what should I be looking for?

This type of conflict will be independent of what firewire port the interface is plugged in, and will effect all three ports, because it is about which physical PCI slot on the motherboard itself the actual Firewire PCI card is plugged into, and whether the motherboard's BIOS or Windows are assigning it to the same IRQ channel as another device, which may be creating a conflict.

Honestly, this a complicated issue, which is dependent upon both the hardware and OS. Run a search for "firewire audio IRQ sharing" and "IRQ priority" to find more information. This may not be the issue, and so I don't want to send you down a rabbit hole unnecessarily; however, it could be worth reading up on, just in case it is.

3) I do often notice MIDI notes, upon playback, being slightly slightly different than how I remembered it while I was playing it. It is very slight, but I can just "feel" that something is off. I had just dismissed it before but now I am thinking I have some kind of compensation issue.

It could also be jitter. With any midi information, there will be a very slight amount of random jitter, due to the way that midi works, and which cannot be disabled; however, it shouldn't be noticeable. If it is, then something is causing the drift.

Frankly, my best guess, based on everything that you have shared, is that this is more likely a hardware issue than a software one. I'm not meaning to be doom 'n gloom here, and there may be a simple software fix somewhere. However in my experience, from many years of PC DAW troubleshooting, when there is an intermittent problem that simply cannot be pinned down, there is either a hardware or driver incompatibility, or there is something going on deep in the system, either with the motherboard or the power supply.

Consider contacting PreSonus and seeing what insights or recommendations they may have.

[sphinxxx]

I found the firewire PCI card is on IRQ 22. It says "no conflicts" in device manager. I also went through hall other IRQ resources and no other had an IRQ of 22.

In Ableton Preferences midi section, should "sync" be selected for my midi devices?


Also I'm using MIDI Yoke, and also' bome's midi translator. Possibily the use of these is causing some issues?

[Akshara]

I found the firewire PCI card is on IRQ 22. It says "no conflicts" in device manager. I also went through hall other IRQ resources and no other had an IRQ of 22.

In Ableton Preferences midi section, should "sync" be selected for my midi devices?


Also I'm using MIDI Yoke, and also' bome's midi translator. Possibily the use of these is causing some issues?

That's good, eliminated the IRQ possibility.

The "sync" button on the Midi page is for sending midi timing messages, such as midi beat clock and tempo information. That shouldn't effect progressive lag or jitter in the desktop. But it doesn't hurt to enable it.

Miidi Yoke and BMT are popular applications, and probably not the source of the problem.

I still feels like a hardware problem to me, something with the FW interface and the PC. How is the power in your studio, and in the PC itself? I once had a desktop which acted strangely, and it was caused by not having a strong enough power supply, which was upgraded and the problems stopped.

Sorry I can't be more precise or helpful, and hope you figure it out soon.

[sphinxxx]

I don't really think its a power issue. The power supply on the PC is a very good one, and its something like 700watts (overkill). Everything is plugged into the same outlet (via a surge protecter). This includes the computer, 2 lcd monitors, the firepod interface, the krk vxt6 monitors, and my computer speaker system.

The only thing thats plugged into a different outlet is my MIDI keyboard.

I found the firewire PCI card is on IRQ 22. It says "no conflicts" in device manager. I also went through hall other IRQ resources and no other had an IRQ of 22.

In Ableton Preferences midi section, should "sync" be selected for my midi devices?


Also I'm using MIDI Yoke, and also' bome's midi translator. Possibily the use of these is causing some issues?

That's good, eliminated the IRQ possibility.

The "sync" button on the Midi page is for sending midi timing messages, such as midi beat clock and tempo information. That shouldn't effect progressive lag or jitter in the desktop. But it doesn't hurt to enable it.

Miidi Yoke and BMT are popular applications, and probably not the source of the problem.

I still feels like a hardware problem to me, something with the FW interface and the PC. How is the power in your studio, and in the PC itself? I once had a desktop which acted strangely, and it was caused by not having a strong enough power supply, which was upgraded and the problems stopped.

Sorry I can't be more precise or helpful, and hope you figure it out soon.

[Synthbuilder]

I may be completely wrong but have you tried changing the midi driver settings in the midi preferences section of Live? Select MME and not DirectX.

[sphinxxx]

Yep, both the MIDI inputs I use are selected as MME (default settings).

I may be completely wrong but have you tried changing the midi driver settings in the midi preferences section of Live? Select MME and not DirectX.