If having issues with PT9 and you use a Lynx AES card, read this

[yeahimsteve]

Hello,

I wanted to share my quick fix with anybody having audio issues with Pro Tools 9.03 and Windows 7, while using the the Lynx AESe card (and presumably an Aurora as well):

Symptom: You attempt to play even a single track inside of Pro Tools and the audio starts to get weird on you. You know that you have a good enough computer, yet audio playback is not smooth, as if the audio is making a "warbled" sound.

The issue: Your Pro Tools playback buffer is not the same as the AESe mixer's buffer. Usually when you go to change the playback buffer inside of Pro Tools, it should automatically change the AES mixer's buffers to the same value that you selected the Pro Tools playback engine buffers to be. The problem (probably bug related) is that Pro Tools changes the AES mixer's buffers to a a buffer setting one value lower than what you set it, as opposed to making them both the same. For example, if you set the Pro Tools playback buffer to 1024, your AES mixer gets set to 512. If you set Pro Tools to 512, the AES mixer gets set to 256. If you set the Pro Tools buffer to 256, the AES buffer gets set to 128, and so on.

When Pro Tools is open and you have the Aurora ASIO driver selected in the playback engine, you cannot manually change the AES' mixer buffer (under Settings-->buffer size). Pro Tools has a hold on it, even though the value of the Pro Tools buffer and the AES mixer buffer are not the same.

Solution: Open the AES mixer and Pro Tools, so they are both running at the same time. This way, you'll know (after messing with the playback engine in Pro Tools) when the two buffers are in sync and fixed. I started off by changing the ASIO engine to something else and that didn't solve the problem. I changed CPU usage limit and that didn't solve the problem either.
Because I have a UAD-2 card in my system, the way I fixed mine was to un-check the box at the bottom of the playback engine window that says, "Optimize for streaming content on audio drives." Then I changed the buffer setting from whatever value it was currently at to a different setting, and then hit the OK button. This "change" resets the Playback engine if even for a brief moment, allowing the playback engine and the AES mixer to get back in sync with each other (to have the same value). Then I opened the playback engine back up and chose the buffer setting that I really wanted. It's not until you hit the "OK" button that the playback engine initiates the AES mixer's buffer to get reset. This final change should also change the AES mixer buffer with it, and now the two are in sync. Then I went ahead and re-opened the playback engine and re-checked the "optimize for streaming content" box at the bottom, now that they were back in sync.

If that box was already unchecked before you began this process, then check it. Whatever setting is was at, change it to the opposite.

Bottom line is, you have to keep playing around with the playback engine settings inside of Pro Tools, then hitting OK to make the setting stick, and then re-opening it and changing the buffer to another value. Then you have to open the AES mixer and go to "settings-->buffer size" to make sure that they are now both the same. Once they are both the same, your playback will work perfectly from here on out.
I figured I'd share this with you all, since I know that I'm not the only one that this has probably happened to. On a side note, the day I installed the AES card and Aurora, Pro Tools and the AES mixer were indeed in sync and Pro Tools would change the AES buffer according to the playback engine buffer properly. It wasn't until I must have made a change to the playback engine under some certain condition that the two got off base somehow.

EDIT:: If the problem persists, un-check the "optimize for streaming content on audio drives" in the playback engine and the sound gets fixed again. Sorry for the confusion!

[yeahimsteve]

Ok, it didn't take long for the symptom to come back, even when the buffers are set properly.
The only way I can get the audio to play back properly is by changing the CPU% in the playback engine to a different value, even if it's a lesser value. Changing it back to where it began after this step also resolves the issue......for now. It will persist, and I will keep changing it back and forth, but so be it.

[DontLetMeDrown]

I have the same setup. It might be from a plugin you're using. For instance, if I try and use IR-L or FG-x when my buffer is set below 128 I'll sometimes experience the same thing. 2 things I've found that help:

1) Raise the buffer or just don't use heavy CPU plugs at low latency

2) Go to I/O setup and drag one of the main outputs to the left or right, then back to its original place and hit "ok" and for some reason that resets the engine.

[yeahimsteve]

My buffer is already set to 1024 (the highest setting) when working on projects like I am, as suggested by Universal Audio when using their latency-inherent UAD-2 cards. What's interesting is that when I was using a firewire interface, I never had this particular problem until I switched to the Lynx setup. I still would have problems but not this particular one.

Part of me is thinking that since I'm using a UAD-2 Quad card, that AES-e16 card, and a heavy duty graphics card, that I'm choking the PCI-express buss whereas before, the firewire interface wasn't using the PCI-e buss. Hard to imagine, seeing as how I have only a single track in this project and it's doing it with only a few plugins (even after taking them all off, the audio is still messed up).

I did recently update my Nvidia drivers and maybe it's hogging more bandwidth than before. I'll have to investigate and see what gives. Thanks for the heads up.

[yeahimsteve]

Ok, I was able to get work done in a couple different projects than the previous one without any audio gurgling so I'm getting excited. I changed my page file on the C drive to "custom" and made it min/max size both to 12GB, which was the recommended size but the system-managed size was not 12GB; it was only 8GB. Right above where I set the page file in advanced performance options, I set Processor Scheduling to "Programs" instead of "Background services." Then on the visual effects tab, I already had most of them unchecked but unchecked any remaining visual effects. Then I went into my Nvidia settings and changed it from "quality" to "best performance," although I'm not sure if this did anything in Pro Tools or not. The idea was to lessen the load visually of the graphics card, as not to congest the PCI-E buss. Not an issue with the firewire device but seems to be necessary in this situation.

Will report back in the next 24 hours to see if my problems are fully resolved with this Lynx setup (once I start to really dig in with the UAD-2 card and FG-X).

[beatsnblunts]

Steve do you find that you have to close PT after changing settings in the audio engine( # of cpu's or processor% ) to get it to work again? I see meter n
movement but no sound tills I close and re open.....
I added sound forge 9 to my system last night and things still work.......next up is putting my Uad/ uad2 cards back in.