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  • VE Pro 5, Kontakt 5: Distorted Audio during Tempo Changes

    I'm using LASS loaded in Kontakt 5 inside of VE Pro 5 on a slave machine that is triggered by Cubase 6.5 (using VST3 64-bit). Anytime there is a tempo change in Cubase, the audio from VE Pro gets distorted. For example, if you have a "ramp" tempo change in Cubase, during the ramp, the audio is distorted, but at all other times, it is fine. Also, if you watch the VE Pro window during the tempo change, the focus randomly and quickly shifts between different Kontakt instances. In other words, the highlighted instances change rapidly like they do when I manually click them. Also, I verified that Kontakt is getting the tempo changes (shown on the master editor tab). However, it seems like the tempo changes are making VE Pro go crazy.

    Here is my exact setup:

    Cubase 6.5.0

    VE Pro 5.1.11252


    Windows 7 64 bit

    I've also tried Cubase 6.5.3 with the same problem. I just recently upgraded all of these tools, but I never experienced this problem in the last version of VE Pro 4. Thanks for the help.

  • By the way, this problem does not occur for VSL instruments or for Play instruments (at least the ones that I've tested). I haven't tested other Kontakt libraries, but I will soon.

  • I haven't found the exact cause, but when I use smaller Kontakt templates, the problem does not occur. I will experiment with different sizes to see if I can create a reproducible test. 

  •  A few things that occur to me:

    1. Are you using tempo synced patches?
    2. Is LASS supposed to work in K5, or is it a K4 library that you happen to be running in K5?
    3. If you use lots of small tempo jumps, rather than a ramp, does the same thing happen?


  • Good questions:

    1) no

    2) I'm using LASS 2, which requires K5

    3) Small tempo jumps do not seem to cause a problem

    Here is some other info I found. I currently have one VE Pro 5 instance for LASS2 with 5 Kontakt instances. As I start to delete Kontakt instances, the problem gets better (less distorted). If I get down to one instance, I *think* it is working correctly. This suggests a possible workaround of 5 separate LASS instances instead of 1 with 5 Kontakt instances. 

    However, I would still like to figure out the problem because this prevents me from getting the most benefits from VST3. I also have a huge template on other machines, so I need to reduce VE Pro instances whenever possible. Thanks for the help.

  • Another interesting result is that if I solo one of the 5 Kontakt instances, I still get the problem. But, if I delete the unused instances, it seems to work. So, the issue seems related to the number of instances loaded, not the number of instances involved in playback. Weird.

  • OK, now we're getting somewhere. Could you try a similar thing with something like Stylus or Omnisphere, to see if those players can cope with tempo ramps? If they can. then it is definitely a Kontakt problem, LASS problem, or both. If they can't then the VEP programmers need to have a look at it.

    The other thing to look at is whether or not things are better or worse if you change the multi processor settings in Kontakt (I can't remember whether or not you have done this).


  • I tried Kontakt with the multiprocessing settings both on and off and it didn't seem to make a difference. The only other libraries I have installed on my Kontakt 5 machine are VSL and Play libraries, which don't seem to be having the problem. However, I also found that if I delete some of the instruments from each Kontakt instance, the problem goes away (even with 5 Kontakt instances). 

    I don't think the problem is with LASS because I bypassed the LASS scripts and was still getting the problem.

  • I just noticed that during the ramp tempo change, the CPU usage in VE Pro jumps to ~99%. This is definitely the problem, but I'm still not sure of the cause.

  • I can definitely say Omnisphere will get some troubles with tempo changes inside VEP on slave. Stuck notes etc. (But not if directly loaded into DP session). Also Kontakt 5 libs that use time machine can also suffer from clarity issues when inside VEP on slaves. random flanging etc. (Again this does not happen inside DP if K5 is loaded directly) Maybe this info might help.

  • In my latest tests, the CPU during a tempo change is over 90% during a tempo change and only 20-30% at other times. Unfortunately, my previous "fixes" (either reducing the Kontakt instances or reducing the size of each instance) don't actually work because a single reduced instance still has the CPU around 85% during a tempo change. So, there actually isn't a workaround because even if I replicate VE Pro instances, the CPU will just jump back to 100%.

    I've tried almost everything I can think of, with the exception of reverting back to VE Pro 4.

  • I also tried all combinations of buffer sizes and reducing the midi and audio ports in VE Pro.

  • Sorry for the swarm of messages, but I keep finding new information. If I completely mute everything in Cubase, so there is no midi data being sent to VE Pro (or Kontakt), the CPU usage still jumps to ~100% on my VE PRO slave.during the tempo change.

  • Progress! It is most likely a Kontakt problem. If I manually disable the host tempo sync in *every* instance of Kontakt, it seems fine. I guess Kontakt 5 has issues with tempo sync and large templates. I'm not sure if this is specific to instances of Kontakt in VE Pro or in general. I'll need to change my setup to test it directly in Cubase, but I'll report back on anything I find.

  • How are you disabling the tempo sync in every instance of Kontakt? What procedure please? Any other discoveries since your last post? thanks!!!

  • Has this thread died? I am too very much interested in a solution to this problem. When I run my large orchestral template with VE Pro and Kontakt I have the same issues with regards to pops. I will try turning off the tempo synch in Kontakt for the instances that do not need it and see if that helps.
    To turn off tempo synch:
    Open the Kontakt instance in VEPro
    Click on the Master button
    Deselect the "Ext" next to the BPM

    Kontakt should now use its internal tempo for synching.
    Obviously this is not a long term solution so I hope someone at who can fix this at Vienna or NI is reading this thread.
    Cubase 6.5 on a Mac Pro 8-core OSX 10.6.8 12GB Ram
    VE Pro 5 on three Core i7 Windows 7 PC's with 32GB of Ram

  • I never thought about tempo sync, apparently I never found the need. however I looked at it, I have external sync enabled in every case; I have projects that double the tempo or more in Cubase. But, I am using Kontakt 4. This seems like an issue for NI per Kontakt 5 to me.

  • I've just joined the club. Distortion, Kontakt-only instruments in VEP 5 (VSL stuff not affected), CPU through the roof, and only on tempo ramp (in Cubase).

    The weird part of it is that I've been working on the same 4-5 projects this week, using the same template, no change whatsoever, no upgrade, nothing. I just opened a project from three days ago and spent half an hour figuring out what was causing this.

    If it was a config problem I'd understand (sort of), but this just happened out of nowhere. Very strange.

    Like everyone here, I deactivated Kontakt tempo sync but this is obviously not a solution.

  • I too have issues with tempo changes using Cubase 6.5x and VE PRO.  I am not sure if it is just Kontakt or not, but my template is gigantic and I run a sound card buffer of 128.  I noticed that when mixing if I increase my sound card buffer to 512 I can mix the cues with no issues what so ever that I hear at 128 samples.  So I assume by me increasing to 512 that it is lowering the cpu usage across all machines getting rid of the problem.  In other words I think this shows more evidence that there is a cpu spike happening on the slave machines during tempo changes.


  • I would really like to see this solved.  Has anyone determined if this is a VE PRO problem or a Kontakt issue?