maxing out polyphony

First, the stats:
PowerMac G5
Dual 2.3 GHz processors
2.5 GB of RAM
Sibelius 3
Kontakt 2
All software above is updated to latest builds.
Second, I have been maxing out polyphony in Kontakt 2 with my bigger pit scores (4 vibe banks, 4 marimba banks, 1 timpani bank, 1 percussion bank).  While individual banks are not maxing out when I watch Kontakt 2 the total number of voices gets pretty high and things get scratchy sounding as voices are cutting out and then everything cuts out.  I know most of the demos have a lot of voices as well so I'm curious how I should tweak my setup to get smoother playback.  Any ideas?  Let me know.  Thanks.
David Knight
Hi David,

Running several polyphonic marimba and vibe tracks is often the culprit in these types of performance problems. You have a pretty sweet setup with a fast CPU and a good chunk of RAM, so I think there may be a few settings you can tweak to achieve better results.

For starters, tweaking with your latency slider in Kontkakt2>Setup>Audio/MIDI Setup>Soundcard can have a significant affect on your results. When latency is set lower, your CPU will work harder. When it's higher, your CPU load will be a bit less. You may want to set this somewhere around 40ms, but definitely play with it to see what best suits your results. If it's too high, you may find that fast rhythms in the drumline (rolls, singles, etc) will sound a little swingy, so it's good to sample a few areas to check results.

Since you have a healthy supply of memory, you can also load more of certain patches into memory rather than relying on DFD, which doesn't perform as reliably as RAM. To do this, open the instrument to edit it. Click on the ";group editor"; button, then click on ";edit all groups";. In the ";source"; section, change the DFD pulldown to ";sampler";. By doing this the ENTIRE instrument will load into RAM.

Or, if you don't want to load the whole thing into RAM, click the ";Instrument Options"; button, then click ";DFD & Load";. Here you can click a larger buffer for the DFD preset. Basically meaning, how much of the instrument will load to memory before DFD needs to kick in to finish out the playback of a requested sample.

One other thing you might find helpful is to shorten the duration of decay after a note is released. If you have a lot of notes flying by in fast tempo (common with marching band pit stuff), it's likely not that important to hear an 8 second decay on every single marimba note. So (as described above) go to the group editor and select the ";edit all groups"; function. Then scroll down to the ";modulation"; area where you can adjust the AHDSR curve. Lower the ";release"; knob to around 1.0k miliseconds. You'll still get full, natural decay while the note is held down, but it will fade away faster once released. This can be particularly helpful on vibes/glock/timpani/chimes since their decay times are typically set to higher values.

Hope this helps, and let us know how your progress goes!
I don't think it's necessary to load 4 marimbas and 4 vibes into your project to get a nice sounding recording.  Since the vibes are a sustained sound, it doesn't much to max our polyphony if 4 are playing at once + other instruments.  If you listen to my VDL2 demos, I only used one vibes and one marimba despite there actually being 3 of each in the pit.  By shifting them slightly off center you still get a stereo effect in the recording and you won't get dropouts. 
Jim,
Adjusting latency was a big help.  The 30-40 ms range works pretty well.  I'm already loading all samples into memory.  I want to still experiment with duration of decay as I haven't gotten to test the latency change on a thicker arrangement yet.  Jesse, your suggestion is good but I'm not sure the individual marimba and vibe banks would function correctly with midi commands coming from multiple instruments.  I don't know...I've never tried that.  Thanks for the replies.  I let you know how the duration of decay experiment goes.
David Knight
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