Audio Mixers

[bogosort]

Hi, that's quite a task they've thrown at you. Honestly, unless this is more of a class assignment than a "production" system, you should strongly recommend to them that they higher a professional.

If it is an assignment or a fun project, start here:
Constant-Voltage Audio Distribution Systems: 25, 70.7 & 100 Volts

[Matt Syson]

Hi
Do not 'design and build' a mixer. It may be fun now but when they call you up on a weekend to fix it you won't be happy.
There are MANY PA system components that can be put together with zoning, metering, automatic level adjustment and anything you can think of and more and it will have a warranty so apart from getting it basicaly 'right' in terms of a system you can rest at night.
No matter how 'custom' you think this installation may be it will all have been done before.
The FACT that 'they' will change the requirements part way through will drive you bonkers too!
Matt S

[johnnyv]

Good advice so far- Hire a professional installer- read up on 70volt systems-you'll be called for the rest of your life to fix it. Free.

Schools are odd ducks when it comes to PA systems. Locally here over the years I've seen them run the gauntlet of who the hire, budgets and what they get. we are a couple of hours away from any major centers which supply technical help. I'm well known and trusted not to at least break anything so I get called in when things go wrong.
Some systems are professionally installed but the schools never seem interested in making the company come back for repairs?? When asked they don't even have a record of who it was?? They toss out components that are probably still on warranty and buy all new stuff. About the only thing never gets changed is the speaker systems.
I have a bin full of TOA input modules I scrounged from dead amps. Oh well.

Don't do it! For a project why not read up on distribution systems and research the components they may need. It would take you 3 years to build a mixer from scratch.