Choice of replacement speakers for Foldback Wedge

Hi Everyone! I haven't been here for quite a while, but it's nice to know you're here to ask when i need some advice!

I'm in charge of rebuilding a foldback speaker wedge. It is about 20 litres, sealed (can make vented if necessary). It has a hole for a 12in woofer and a 10.5in by 4in piezo tweeter horn. I want to keep it as cheap as possible. There's a possibility of making it active by adding a built-in amp. this will probably be 70W or less. The wedge is mostly used for vocals.

The horn appears to be okay (the woofer wasn't too healthy, and overdriving it with feedback from a Crown amp didn't help. The amp survived;) ). However, it's a cheap Realistic, and i have no idea of the sensitivity, power rating, or frequency response. By ear, it sounds like about 2kHz + . It has a 4.7uF cap in series with it. I don't know if that tells you anything. I don't mind replacing the horn (the driver isn't detachable) if it means a good match between tweeter and woofer.

I have had a small look at some peerless, diachi, and other woofers, but they all get rather large humps at about 100Hz in the small sealed box. Not that i'm too worried about fidelity. Any ideas? I don't have any software for simulating vented boxes....
 

Brett

Member
2002-01-07 6:02 pm
Try P.Audio. Some of their stuff is quite good. They have a large catalogue of parts, and the cheapest 12's cost about $A70/$US35 ea. There are also a wide variety of cheap driver/flare combos from around $A45-ish. I looked at doing something similar a while back.

However, with ANY 12" driver in a sealed box I think you'll be struggling to get less than 100Hz out of it.

Cheers
 
thanks for the responses!

Yes, it is a tiny wedge for the size of the driver. It's a kit, and i'm not sure whether it was meant to have a 12" in it.

No, it doesn't have a x-over.

Yes, i think you're right, 70W won't be enough. However, it's not going to be used by picky people, for the most part.

What's your website, Andy? I've already looked at http://www.ctscorp.com/pzt/speakerappnote.htm#hints

The piezo is a Realistic - the numbers on it are: 40-1279, 8 ohm, 6A9
 
400w ? Don't Bother Coming....

The last AC/DC show I worked had about 30 kW of Amcron amps for drum monitors, side-fill and wedges.
I read an interview with the monitors engineer where he described the stage sound as a big loud hifi sound shell, but critically sensitive to the merest adjustments.
The article also said that at the FOH mix desk way out in the venue, measured sound level was 126 dB with the FOH system turned OFF !.
God knows what the SPL is on stage, but the band guys still have sharp hearing.
Pete Townsend blames Walkman headphones for his now profound deafness, and not stage sound.

Eric.
 

pinkmouse

diyAudio Moderator Emeritus
2002-04-03 7:15 pm
Rotherham, England
Ahh, Arena gigs, love em...

But that was just for him personally, arranged in a horseshoe around his mic, for small college gigs! we had another 8 for the band.

For seriously loud foldback, the loudest I experienced was sitting in the crew room at Wembly arena, in about 1990, and being able to hear every word that Bob Dylan was singing, with the main PA off due to genny failure!