The Ambience Reverb can no longer be used in Finale for MacIntel. The developer who created this reverb plugin has decided to cease development and will not be updating it to MacIntel. Edit: I have just been informed that there may be a chance that development will continue on Ambience. Information will be released if that comes to pass.
I will try to give approximate instructions for how to get reverb working in MacIntel. Keep in mind that I run an all PC studio so my step-by-step instructions may be slightly different compared to Mac. The steps should be very similar on both platforms though and the following should help you figure it out (at least I hope so):
1. Open the Native Instruments Setup window. Click on the "Edit" button.
2. Click on the Aux Send activation button. Note the Aux Send level sliders.
3. If they are not already open, click on the "Outputs" and "Show Inserts" buttons at the top of the KP2 interface to display the mixer section. On the Aux 1 channel strip click on the first insert down arrow and choose "reverb."
4. Open the Reverb module as shown below.
5. Turn the "Dry" slider off. Reverb presets can be chosen from the "Pre" button.
What I have described above is the configuration of an Aux Send arrangement for reverb. This is the most flexible approach, allowing users to apply different amounts of reverb to individual instruments as needed while efficiently using only one reverb module. If all instruments are going to be sent to a single stereo output and the user wants to apply the reverb to all instruments equally then the reverb module could be placed in one of the channel inserts for that single stereo output.
I was very pleased to find this excellent set of instructions. It has allowed me to make headway with this form of reverb for the first time. Presumably it will also apply to Sibelius. However, I would very much appreciate an expansion of the method for applying reverb to all the instruments at once. When you come to Kontakt 2 via a notation program you get little in the way of documentation and its hard to get into.
Is there a way to simply run the freeverb-c VST / AU plu-in? This is a free download, and I have used this in my Bias Peak software for a long time... I haven't tried to use it in my Finale/K2 sandbox, but it's a heck of a lot easier to use than ambience.
search for freeverb-c.component - not hard to find.