Think of the Children: How much sound do I really need?

[Panama Dave]

Hey folks,

New here, and new to DJing. I'm sorry if this question has been asked before, but I'm not even sure how to search for it.

I'm going to be setting up an underage dance in the local Lion's Club gym to run about every 2 weeks. The space is about 50' x 100' (with a 20' ceiling), and it will be divided in half by a lightweight curtain (to project videos on). The entire space in concrete.

I have a pair of Mackie 1530z speakers, and a pair of 1530 (none "z") speakers. A DJ friend said that a single powered sub could handle the bottom, while another DJ friend said that I have nowhere near enough juice or speakers for the room.

The space will have about 300 kids in it. It doesn't have to be professional quality, but I want it to sound better than somebody's iPod connected to some home speakers and an amp.

As I said, I'm not a DJ, but I AM a dancer. When I go to nightclubs, the music is always too loud, and even with earplugs my ears are often ringing by night's end. It seems to me that the clubs are using far too much sound for their space.

I can place the Mackies up on risers if that would dispearse the sound better around the Lion's Club gym.

So what do you guys think: How much sound is enough? Will the Mackies and a sub be enough, or do I need 6-10 more speakers?

Thanks

[gootee]

What is the rated max output power of whatever you're going to drive the speakers with?

Personally, I don't like it so loud that I can't hear someone trying to talk to me. And the entire room wouldn't have to be a dance floor. Maybe you could localize the loudest portion of the room, so people would have a little choice as to loudness.

One way to find out would be to set up in the room, a week or two before the first dance, and do a sound check, and some experimenting with layout. You'd have to try to factor in the effect of the place being filled with people but it should give you SOME idea of whether or not you're way off, at least.

[DUG]

IMHO good sound is better than loud sound.

Went to a recent show and they tried to turn the vocals up to "11"...system could not handle it...did not sound good.

Start with 50-100W / ch and bring a backup amp.

The sound check idea is good...actually each week will be its own sound check and you can modify based on experience.

You might find someone's parents in the audience that might be able to help you...you never know.

Keep us informed.

[JMFahey]

Agree and add: those kids (thanks God) will not be dripping alcohol through their ears and pumped up with Extasy or stuff like that, plus having perfect ears 10X more sensitive than ours, so you don't need to smash their eardrums with Jet takeoff SPL by a long way.
Keep it sensible and you will succeed.
You already have far more speaker muscle than what's needed, just experiment with placement for even coverage in the dance area and avoiding thunderous resonance; being "all concrete" I'm sure there will be more than a couple spots where you do *not* want your speakers to be.
Move them around and also walk around yourself until happy with placement.
If you sound acceptable with an empty room, it will only improve with people.

[Panama Dave]

The Mackies seem to be tri-amplified, and to my ears, do pretty good on the bass already.

http://www.mackie.com/pdf/sr1530_ss.pdf

[Panama Dave]

DUG,

"You might find someone's parents in the audience that might be able to help you...you never know."

Actually, I"LL be in the audience. The real DJ is Father Carlos, I'm just buying and setting up the gear. I'll be able to move around the room throughout the dance and check for sound (clipping, muddy, etc.), not unlike how I give feedback to the DJ's I go dancing to.

[Panama Dave]

JM,

Should I try to place the speakers in the corners facing the center, to provide sound from the whole dance area? Or would that cancel each other out?

[JMFahey]

Don't think so, I fear that will give excess bass .
Move them around and let your ears be the judge.
Full concrete large spaces are treacherous.
Really don't have a "magic formula", each room has its own quirks.
But don't overthink it , I'm sure in less than 30 minutes you'll find an arrangement you like

[gootee]

There are some "formulas":

Cardas Room Setup Guide

[chrispenycate]

I can place the Mackies up on risers if that would dispearse the sound better around the Lion's Club gym.

Gettem high, and aimed down. That way the kids act as absorbers and you get a bit less concrete box. Obviously, acoustic treatment of the room would make the listening experience considerably more pleasant for all concerned, but I do understand this is not always an option (although the materials don't have to be expensive, and if you have lots of available manpower – OK, kidpower – the operation can even be fun).
What's more, getting the tweeters above head height means that you're not annihilating the front rows with highs while those further back get just the thump.

And, on thump, subs give a convincing body punch impact while not destroying eardrums with screaming treble. Unfortunately, by removing the ultralows from the full range system they allow it to get louder; if it's me doing the mixing I always like some spare power, everything sounds better when not running at its limits (except metal bands), but if I don't trust the guy behind the faders, better a system that stops…

Too much bass? If you'd seen how the EQs are set in your average club… The concept of flat frequency response doesn't really come into a DJ's mental processes, and they've no longer any real need to worry about feedback.

What exactly are these dancers under age for? Alcohol? Some of the audiences that wanted the highest levels I've been asked for (audiences, not reggae drummers or metal guitarists) have been in the 16-18 year range.