Vienna Symphonic Library Forum
Forum Statistics

190,362 users have contributed to 42,737 threads and 257,119 posts.

In the past 24 hours, we have 4 new thread(s), 10 new post(s) and 37 new user(s).

  • Changing soundcard sample buffer size in Reaper makes hosted instruments inside VEP go out of sync with project tempo.

    Changing soundcard sample buffer size in Reaper makes hosted instruments inside VEP go out of sync with project tempo.

    I am running Reaper 6.82 on Windows 10, RME babyface, Asus TUF laptop - Ryzen 7 4800h CPU with 64GB of RAM.

    I have enabled loopback routing in Reaper so that the midi tracks are also the audio tracks as per this post: https://forum.vsl.co.at/topic/52638/how-to-get-ve-pro7-to-route-properly-with-reaper-set-up-more-than-16-midi-channels-per-instance?_=1723928355949

    *DISCLAIMER* - This is my first proper project running VEP with Reaper (I was previously using Sibelius).

    All of the instruments in this project are vipro instruments hosted within VEP, apart from an instance of Pianoteq on its own track in Reaper.

    Scenario: Project contains about 60 odd tracks of which I'm only actually using about a dozen. I have four instances of VEP. See screenshot. I have been live playing the instrument parts into Reaper with a bit of quantizing subsequently. Playback at 256spls sounds in time though I have noticed that the VEP gui hangs a little at times, i.e you don't see the different articulations being triggered. I thought I would increase the ASIO buffer size as a way to overcome this small problem. After doing that all the VEP instruments become increasingly out of time with the project tempo with every increase in sample buffering. The pianoteq instrument that is not hosted inside VEP stays in time.

    If I host pianoteq inside VEP it then becomes in time with the other hosted instruments but equally out of time to the actual project tempo.

    I have tried toggling one or two settings in reaper to do with fx processing and multi-processing settings but at the moment I am hitting a brick wall.

    It does not seem to be a hardware performance issue as running task manager doesn't reveal any CPU overload or anything.

    One thing I’ve noticed is that in the bottom right corner of VEP the number here doesn't change. See screenshot. It’s always on 512. Should this reflect the soundcard sample buffer size?

    General layout:

    Does anyone have any ideas?


  • Update:

    I should perhaps point out that I am running MIRx in my project.

    I have been further testing my setup today and found the following: If I go through each VEP instance and set the MIRx sample buffer to 256, say, this is reflected as 256 in the bottom right hand corner of each VEP instance. If I switch off MIRx altogether I then get 0. I am guessing that VEP is somehow not picking up my sound card latency settings(?)

    BTW - is there a way to globally turn off / bypass MIRx in VEP?


  • Update #2

    I created a new Reaper project with standard 'flat' routing, i.e. no track hierarchy - no folders and no loopback routing. I change my soundcard sample rate and everything stays in sync. The problem disappears. So it looks more like a Reaper problem...