Live-Performence software

Question

I a planning to show off one of my video productions to a large audience. I'll have my PB G4 to show the video. Now, last year audio wasnt so hot....
What software can I use to test the sudio system and optimize my computer and/or mixer for best audio performance.
Thanks.

Answer 1

Given the mixer & speaker descriptions, it is likely the auditorium has one left, one right, & one sub-woofer speaker system, with the sub-woofer (the 'point 1' in 2.1 sound) being derived & driven from the Mackie's built-in sub-woofer crossover.
This is a common method used in professional & commercial grade sound reinforcement systems to augment & control deep bass reproduction. It is unlikely you can improve anything by trying to create your own sub-woofer 'point 1' signal, so just concentrate on producing the best "2.0" signal (IOW, plain old stereo) you can manage, & use the Mackie's controls to tweak it for the auditorium's acoustics.
Unless you have access to sophistocated test gear & experience using it, you are probably better off using a well recorded music CD or the equivalent & your ears as a reference for setting up the Mackie. Spectrum analyzers & 'pink noise' test signals are useful tools, but only provide a rough guide for what program material will sound like. They require interpretation & multiple measurements in various seating positions to distinguish the effects of direct vs. reflected sound, which is usually just as important as overall frequency response in setting EQ for best results.
If you do decide to go with measurement tools, check out (I kid you not!) "Spectrafoo" at http://mhlabs.com/metric_halo/products/foo/
This is an excellent suite of Mac-only, software-based measuring tools, & there is a demo version available. It is not cheap, & still requires experience to get much out of it, but it is well regarded among professional live sound mixers as best-in-class. (You will also need a good lab-grade measurement mic & a preamp to use it for accurate live sound measurements.)
A few other tips:
Feed the output of your Mac to the line inputs on the Mackie, not the XLR's, which are for mic level signals. You will probably find it most convenient to use one of the stereo channels for this, since it allows you to use one set of EQ controls for both inputs. Use high grade cables, but avoid using ones that are too stiff or put a lot of strain on the mini-jack on the Mac. If necessary, use a short adaptor cable & tape the 'breakout' from a single cable to two cables terminating in 1/4" plugs to something secure, to avoid accidents & intermittant connections.
Use the PFL/Solo button to set up the input gain on the Mackie. You want the average signal level to be around 0 dB at the channel. The Mackie has excellent headroom, so overload on peaks is unlikely. Adjust the final output level with the channel fader, leaving the master fader around 0 dB. This will give you the best signal to noise ratio. Try to use channel EQ sparingly, after first using the built-in graphic EQ to adjust overall frequency balance for the auditorium's acoustics. Make your adjustments at about the same sound level as you expect to use during the presentation, or slightly louder, since the ear's sensitivity to different frequencies changes with loudness & an audience will absorb some sound.
Bring a spare set of cables, some gaffer's tape, & a good set of headphones. A small flashlight is also handy for finding things that roll under out of the way places.