Help! I need some advice on AV for a presentation in a gymnasium

[HuskerTX]

Guys, this will likely be my first and last post on this forum - I know very little about AV and I'm coming here for your help, so thank you in advance.

Short version: I am making a presentation with guest speakers in a basketball gym. At first, it appeared that the crowd was going to be around 150, but now it looks more like 400.

I have used a small Fender portable sound system for up to 100 in this setting with no problem. I've never even cranked the volume of the unit past about 2.5 and it was plenty loud.

But, I am worried about just two speakers not delivering quality to an audience of 400. I realize in a gym that the accoustics are horrible by nature, but this is a pretty big deal and I want it to be optimal without going crazy.

Questions:

I don't see a jack on the fender sound system for additional speakers. Would some sort of pre-fab'd splice arrangement work for additional speakers?

Or would I still be OK with just the two speakers, and simply crank them up so that everyone can hear?

Is there any danger whatsoever of a wattage/voltage overload on a 110 plug in socket? I would be running a laptop, a projector, the sound system, and two to three wireless mics. Any dangers here of the whole thing shutting off mid-presentation due to power overage?

My speaker wires for my Fender portable unit run about 50 feet long each. But for this, I'm going to need to find some 100 foot or more. Where do I buy that? Is there any issue with this? Degradation of quality, chances for shorting a circuit, etc.

Thank you immensely. With 400 people, I need this to be right - I can't afford a screw up.

[Mr Peabody]

I think you'd be fine with just the 2 speakers since it seems you have plenty of power to spare. Adding more speakers would just create new problems for you. Some PA speakers have output jacks for daisy chaining, if yours do that wouldn't be so bad to add another set. You could do a trial set up and walk around the seats to see if you hear every where.

100 feet is a good stretch but I think in your case you'd be fine. You can buy decent cable almost any where from Radio Shack to parts sites online. A larger gauge would be better, maybe 10 or 12 gauge.

[blackraven]

If you have trouble finding 10-12g speaker wire, look here and buy the unterminated wire-

Speaker Cable at Blue Jeans Cable

You can get the 12g bare wire for 52 Cents a foot.

[Unworthy]

I agree that additional speakers could probably be daisy-chained, but that may be problematic, I wouldn't recommend it if you're a novice. Fender is not known for selling high performance PA equipment and the only real advantage of added speakers is to expand the coverage of the sound, not increasing the volume to any significant degree. The resistance your amp "sees" with added speakers may fall dangerously low for that amp leading to the amp shutting down, or worse. You might also be able to rent, rather than purchase, the additional speakers and/or cables you need from a music store that rents sound reinforcement equipment.

D