JBL 2445 and Altec 421 or Jbl 2225/2226 for school theater

Hi.

I'm building cabinets for a high school drama theater. Its a volunteer project.

I've been recruited to help my 16 year-old's school drama/theater department improve the sound reinforcement system. They currently have a very beat up and small system with bad wires, mics speakers . . . its just bad.

An estate recently donated a concert reinforcement system to the department, but its old gear. Based on my best count (kids kept moving things) here's what we have:
6 - JBL 2445 with Community horns
2 - JBl 2460/61 with 2345 horns
2 - Altec 802 (not sure on this, no label)
3 - Altec 811b
2 - Altec 290's
6 - Altec 15's 421 8 and 921 8
2 - Altec 1003 (not sure if that's what they are)
8 - Gauss 5842 (4582's)
8 - EVM 15L
1 - Altec angle horn (plastic) and driver
1 - Cobraflex
8 - Community Leviathon horns in cabinets
Misc. snakes, QSC crossovers, Yamaha crossovers, some blown amps.

A little over half the stuff reads good with a volt-ohm meter. My thought was to take the most recent gear, probably the JBL 2445's, and either take good Altec 421/921's to build speakers or sell the woofers and buy newer JBL woofers. I'm working on fund raisers and selling the remainder of the gear to purchase 1 or 2 Crown class D amps, DBX driverack PA, a new mixer and some decent mics like SM58 or SM 57. Since this is theater work, something like the Crown PC 160 boundary mic and condensers may be better.

As I'm typing it really occurs to me that the woofers will need to have more Xmax than the available drivers. 2225's or 2226's would likely survive better.

I've got to keep in mind that students will use/abuse the final product. Its got to be tough, but I'd like to get good sound. The likely abuse sort of rules out building A-7 or 846 type cabinets. The final product will have to handle modern full range music. I just have to anticipate students and they will do crazy stuff. Maybe I need to filter below 35hz.

So my first step is to figure out what's junk and what might have value. I'm attaching pictures see if there's any thoughts about what to do with some of this equipment and on using newer woofers.

There was supposed to be hands clapping after "but its old gear.":applaud:

Hi Jim;

It's hard to tell from the pics so here's a few questions:

Do you know what Community horns are on the 2445's? Or can you get a frontal or 3/4 pic?

The fiberglass flares stacked on top of everything look maybe like Community Boxers?

Can you get a pic of the Levi's? And what's in the big black boxes?

Some of the old Community stuff sounds really really good.

So, is this kind of a permanent install or will it get moved around? What is the size and scope of the system you envision

Thanks for the reply 1audiohack.

I will be able to get more pictures this weekend. I was at the school today for an hour and felt like I was disrupting classes.

The install will be much smaller than the stack of gear implies. I haven't gotten too far on design, but probably 2 or 4 speaker cabinets 4 to 6 cubic feet. Probably an active crossover 2-way system. I'll consider subs if possible. The units will probably be on wheels, so they can be moved out of the way when not in use. I don't expect them to leave the theater, but I suppose they could be used outside for shows. So, that's not really a design requirement. This theater department is pretty active and holds a regional drama festival each year. The building itself is 60's or 70's, so not designed for accoustics. I'm thinking about ways to improve that.

I thought the Leviathon horns might be boxers, but found pictures that looked like the main units on the web under Leviathon. I'll get pictures this weekend. These are way to big for my project, so I'm trying to figure out how to connect with someone interested in them. The department head can only store them for a couple weeks, then they've got to go. At that point, I suppose I'll just have to pull the drivers.

The boxes are either road cases for rack mounted systems or for cables. The largest boxes are dual 15's in the Leviathon/Boxer horns. I found the JBL 2461s (no diaphragms) in the road cases with the 2345s and a Altec 511b. Some working equipment may have been removed by the estate. This weekend I'll use signal generators to test the drivers. There's two cabinets that may be genuine Altec 2X15 horns.

The Community horns on the 2445's are actually in pretty good shape. I just don't know if the dispersion pattern will work for the room size.

I really don't know much about the Altec multi-cells.

Hi Jim;

If those big flares are the fronts of Levi's or Boxers and you don't want them/can't use them I will buy or trade for them. I think I have a DriverackPA that's not in use as a possible start, and some Crown amps as well. If in your travels if you find any Community M80's or RH60's, I am looking for those.

I have never knowingly heard the Altec multicell horns, they may be of considerable monetary value on the open market, I don't know.

I will be glad to help you identify what I can and I am interested in what you find, looks like fun!

All the best,
Barry.

8 double 15" Leviathan boxes and horns. ;-) You probably have you bass right there. Especially if the Gauss 4582 woofers are still good. Low in power but high in numbers... Or load the bass bins with 2226 and that would most likely be bulletproof for a drama school and occasional Prom Night...

http://i250.photobucket.com/albums/g...d/File0085.jpg

What about using a pair of multicells on 2445s and call it a day? Build a simple 2-way system. If you really need infrabass, then sell of some of the parts and get a pair of twin 18" subs to complement you bass horns.

Basically, I say, spend some time checking out the drivers. Install them and see how it sounds with a proper active digital crossover and a couple of amps. Damn that sounds like fun.

1audiohack, send me a PM. I think we can work something out. I'll see if I can get some pictures before the weekend. The kids have a performance tonight, but maybe tomorrow.

Lee in Montreal, at first I thought about keeping a couple of the larger bins. The cabinets were well thought out, with wheels. We had a small girl moving one! Anyway, the room size is the restriction. I haven't measured it, but seating area looks 60 deep by 120 wide. The dispersion pattern would be a problem. I don't know what the dispersion is with the multi-cells. Regarding them, I'm very concerned the students would quickly damage them. :eek:

This project is forcing me to consider durability and likely abuse along with sound quality. One kid got a small bolt in the throat of a blown 2445. No damage! The bolt was just held against the screen by the magnet. What was funny, was watching the kid turn the unit over and not figuring out why the bolt wasn't coming out. I watched for about five minutes.:D

120 wide by 60 deep will indeed highlight dispersion problems with the midhorns.I have just embarked myself experimenting with JBL 2360 horns that are cinema theater horns, designed to have a wide dispersion with great non-directivity from 500Hz to 17Khz. Those are very transparent as you basically don't notice the source of the sound. You move around the room and there's no beaming of "hotspot". The 2360 can be purchased for cheap and they work on 2445 drivers. Perhaps you can sell the multicells fro good money and get those fiberglass 2360. They could be installed on a stand and bolted to a bass bin. And you get to keep it two-way...