Big-huge-enormous Jbl.....

[Joe Alesi]

Hello

I hope everyone is happy and well.

I just thought I'd share a pic that I saw today.... I'm thinking LE-375 on 2309 (X64 !!!!!!) and LE-15A???. Any thoughts ...I would love to know the story behind the pic if anyone knows. Some sort of test facility or acoustic weapon perhaps???????????????????

Edit:
Cant be LE15A, as the front plate is too thin (gap too shallow). Maybe D130????

http://i24.photobucket.com/albums/c11/crhood/hugespeakerls.jpg

Best
JA

[pos]

is it some kind of unity horn?

[Hertzz]

Wow! Your neighbors sure would get cranky living next door to these!:D

[HCSGuy]

It is detailed in the Lansing history on this site. Look at the Stereo Sound article under general information. If I remember, it is a Transducers, Inc. project for NASA for testing against vibration. The diaphragms in the 375 drivers were stainless steel, I think. Here's a link to the story:
http://test.audioheritage.org/html/history/legacy/09_thomas_background.htm

[Joe Alesi]

Hello Everyone,

Thanks for the responses and to HCSGuy for the link.

You Guys are :applaud::applaud::applaud:

Best
JA

[JBL 4645]

Is it THX certified! :D Interesting design the way this shaped what was the max SPL db and frequency response.

[Harvey Gerst]

Most of the specs we got from the government were usually around 50 Hz to 10,000 Hz at SPL's of 150 dB or more. I remember the first one we built was a 6 foot horn - in reverse. The horn was made out of 1/4" iron plate. The 6 foot by 6 foot opening had a 3/4" wood plywood panel with a lot of 375's and D131's on it (I think). At the other end. was a 1 cubic foot box for the equipment under test. That combo could generate 150 dB into the box.

I think the government used it to test gauges for jet fighters.

When Ed May came on board at JBL, Bill Burton moved to La Crescenta to start Transducers Inc.

[pos]

The US army still needs to do parties it seems:
http://www.youtube.com/watch?v=o36Kp6veJ6c

[stephane RAME]

Hi,
64 copies JBL 375 (+15 dB) x 60 watts (+15 dB) = 30 dB
Stéphane

[Eaulive]

The US army still needs to do parties it seems:
http://www.youtube.com/watch?v=o36Kp6veJ6c

Would like to see specs on this thing....
They claim the need to achieve 94 to 104dB at 250m at a frequency between 15 and 20Hz.

This would translate to around 142 to 152dB at 1m.
Loud, especialy at 15 Hz it's not an easy task.

[cosmos]

I'd like to be the scrap man called in to haul those damn old things away..:D

[badman]

Bet the guy in the pic was happy to have spring terminals :)