Looking for a large room speaker system for a PC

[Kherr]

I'm looking for 3 different speaker systems (low, mid, and high range) specifically designed for large rooms (see picture for room size). Low range slection needs to be between $50.00 and $200.00 USD, Mid range selection needs to be between $200.00 USD and $500.00 USD, and High range selection needs to be between $500.00 USD and $1,000.00 USD. Something for a small project for my tech support job, but all I can find is small speaker systems that wouldn't work for the whole room...

These slections need to be WIRED, NO WIRELESS ALLOWED! They also need to be able to have select speakers enabled or disabled depending on where the class is sitting because the sound system is going to be used for movies, presentations, and lectures. They also need to be for use with a computer because that's what they're going to be hooked up to. Preferably no receiver systems, but no biggie if they are part of selections.

I've been digging for around 2 hours now and everything I find isn't designed for rooms this large. I really don't wanna have to go home theatre system, but that may be the only option I can seem to find.

Anyone?

(oh, and here's the room size for the system)

Room's probably 75+ feet long, and 25+ feed wide

[Hot Trout]

What are your inputs (input devices)?
How large is the area that needs to hear the sound?
Is this mostly for human voice/music/video all or any?
What quality of sound do you require?
Have you access to the ceiling for speakers?

[SE7EN]

you may end up being better off going to a pawn shop and buying the individual speakers there, then buying the wire separately. you should be able to grab some 3.5mm jacks and thread the wire through them for use on a computer, assuming you have output for multi-speaker setups. otherwise you will only have stereo, and would be limited to turning off only 'sides' of a room, unless you have a digital out option, then you would need some sort of receiver. Going this option may require use of a cheap amp, but I don't know how loud the ambient noise in the room would be, so it is my best suggestion at the moment. If you were to go with computer speakers, they can get pretty loud, but you are limited on speaker-wire length (unless you are willing to cut the wire and add more).