I have taken over a show that is using Ableton live to playback sound effects and music. Ableton is run on a mac sent via firewire to a Presonus interface the "Firestudio Project". The interface is being used as a router to six speakers and a sub.

The session has been saved but the sound levels for each performance seem to charge either a lot louder or quieter. There is no adjustment to sound on the interface. What could be causing the change in sound levels?

I have not used Ableton before I have used Qlab. Could I get other peoples opinons, what do other people think of Ableton as a method of sound effect playback? Good or Bad? Would you use Albleton or other software for a mac?

cheers

Long shot but thought I would try my suggestion. Could the loudness/quietness be affected by the amount of people in the auidience? More people in the audience meaning more absoption of the sound, thus the sound being quieter? Or would that more affect the reverb? Again I could be way off!

sadly not it was a lot quieter when the less people in and a lot louder when the place was nearly full

Another long shot, but are the sound levels of the laptop at full each time? Always worth a check.

The system volume control will be disabled when the Firestudio is connected, and either way, it won't affect the volume of Ableton which addresses the soundcard through Core Audio seperately, so that's not gonna be the issue.

It's either something to do with Ableton, or maybe even a dry connection or a polarity/cancellation issue somewhere along the line. I do have Ableton but I hardly use it (I've just fooled around mashing up stuff, nothing serious) so I can't really speak for the software. As far as a polarity or cancellation issue goes, describe how the speakers are connected to the interface. Does the signal go into a mixing desk and then into the speakers or (gulp) are the speakers connected directly into the interface?

The speakers are connected directly into the interface!

I'm an Ableton Live user both professionally and personally.
I think it's a great program once you get into it, mainly because of the amount of tweaking you can do "on the fly" without it affecting your generic set-up.

Are you using Live in "Session" view or "Arrangement" view.
If you are running in Session view, then check to see if the "As Arrangement" icon (beside the play and stop buttons) is highlighted in red - if it is NOT, then the playback is being controlled by the info stored in the Arrangement session, any volume changes may be recorded in the Arrangement, which is why you wouldn't SEE them in Session view.
Using Arrangement view to check for any "channel level" automation on your audio channels may also be worth a try.

In YOUR setup, it appears that your loudspeakers (or the amps they are connected to) may be connected directly to your PreSonus interface.
Ableton is your MIXING DESK, everything you need is contained within the Ableton software or the outboard VST's you drop into it.

Ableton is very impressive as a playback device for theatre and performance - as long as you learn it first!
However, it contains many elements that a theatrical user will never need; and as such a more basic software may be more suitable.