Taming the Flexi-time latency beast

The Latency Beast. It's more frightening when not in silhouette. (Courtesy nutmeg66 on Flickr)
The Latency Beast. It's more frightening when not in silhouette. (Courtesy nutmeg66 on Flickr)

If you find that Sibelius always seems to be a sixteenth note (semiquaver) or an eighth note (quaver) behind you when you’re using Flexi-time note input to play notes in from your MIDI keyboard, then chances are you have been struck by the Flexi-time latency monster. Read on to find out how to tame this beast.

Latency refers to the delay between Sibelius telling your sound device to make a sound, and that sound actually coming out of your speakers and reaching your ears. In order for Flexi-time to work effectively, that delay needs to be really short: if it takes a long time for the metronome click to reach your ears, then by the time you hear it, Sibelius is already halfway towards the next beat, and the note you play on your keyboard in response to each click is going to be late.

The most common cause of this problem is when you are using a high-latency playback device, such as the built-in Microsoft GS Wavetable Synth. This is the default playback device in Sibelius 5 for Windows, and it may also be the default in Sibelius 6 if you have not installed the supplied Sibelius Sounds Essentials sample library. Unfortunately, the Microsoft GS Wavetable Synth has really high latency, even if you have the fastest computer in the world: it can take as long as a quarter of a second for it to produce a sound.

You’ll never get great results in Flexi-time if you’re using this device, so the first step to taming the latency monster is to switch to a lower-latency playback device. Choose Play > Playback Devices and choose Sibelius Sounds from the Configuration menu (or Sibelius Essentials (32 sounds) if you’re running Sibelius 5), which will activate the Sibelius Player sample player (or Kontakt Player 2 in Sibelius 5). This should make a tremendous difference already.

If you still discover that you have any problems with notes being entered late after switching to a low-latency playback device, go back to Play > Playback Devices and click Audio Engine Options. Make sure you’ve chosen the best available choice in the Interface menu, preferably the one with ASIO in its name (and if there’s no ASIO choice, you should think about getting an ASIO-compatible soundcard or audio interface, or at least try installing the ASIO4ALL universal ASIO audio driver), or failing that the one with DirectSound in its name. Check that the Buffer size is set to 1024 samples or lower to reduce the latency further. Ideally, latency should be less than 50ms to get optimal results.

Having tamed the latency monster, you should find Flexi-time a lot more usable.


  1. David

    I found this while looking for a way to add my OWN tempo to a performance. I have GREAT trouble playing along with a metronome; I’d much rather create my own tempo, either by tapping out my tempo as I play or adding the tempo upon playback. One needs to ‘read between the lines’ when it comes to Sibelius documentation. Am I missing something?

  2. Arthur Kay

    Having just bought a new desktop( Faster !) P.C. and stuggling with Windows 8.1 ( after Vista ), I find the latency bad – near 69 ms.
    I am using Sibelius 5 with Kontact Gold sounds.
    Are there any ways of improving the latency ?

  3. Donna

    I have just got Sibelius 5 and am having trouble with latency when trying to input notes via a midi keyboard. Any help very, very gratefully appreciated.

    Thank you so much.

  4. absolutelynot

    absolutely not true. flexitime in Sibelius is f*cked. and that’s a fact. asio4all works flawlessly in ALL other software, in Sibelius it’s just completely f*cked. I have so much latency it’s unusable. this is not even an issue of getting better latency, it simply is broken. I can’t wait 1 second until it considers starting to play a sound.

  5. Kirsteen Murray

    Thanks so much for this. I had terrible lag with the new Sibelius and did what you suggest in the last paragraph and it works perfectly now!

  6. Milos Sladecka

    I got the same problem (1/4 sec. latency with Microsoft GS synth) and after lot of time I found simple solution, that works for me very well. I have got dig. piano Casio that is conected through USB as midi input device. But I have found out that I can use it as output midi player as well. In “play – setup” I clicked “new”, created new configuratin with Casio USB general midi as active device, saved it and now I use Casio as source of Midi for creating notation and simultaneously as midi player, so by that way I am bypassing sound card of PC. It works with almost zero latency (as it uses hw sound generator of keyboard, not sw player of PC) and I can finaly create score on notebook without external sound card.

  7. Mark Jones

    I’m using Sibelius 6.2 and recently upgraded my Mac OS to Yosemite. Now older charts show “TM” over some bars that are now missing 8th notes. When I erase the part of the measure that contains the missing note the TM goes away until I try and dot a note to properly populate the measure time wise. This could be an OS incompatibility but I’m hoping I can turn “something” on or off to prevent this. Has anyone encountered this before ?

  8. Diedrich Friesen

    I’m having lots of problems with the latency in my Sibelius. I purchased it online one year ago, but now I cannot get technical assistance for it. I have tried all the suggested settings changes but it still does not work. Please help.

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