woofer impedance folded horns

[Harvey Gerst]

No one off JBL designs?

No things that would have been fantastic but never made it to production because they would cost too much to produce?

JBL had to have a few things no one knows about! Not even 1?

Actually, no. Pretty much everything we came up with went into production. Except one.

I remember Ed May built a woofer that put out a ton of pure bottom end without much distortion. He played a 27 Hz sine wave through it, and it was like your head was instantly pressurized; you couldn't talk or hardly breathe. Made everybody sick to their stomach. Don't know what happened to that speaker.

[spkrman57]

Actually, no. Pretty much everything we came up with went into production. Except one.

I remember Ed May built a woofer that put out a ton of pure bottom end without much distortion. He played a 27 Hz sine wave through it, and it was like your head was instantly pressurized; you couldn't talk or hardly breathe. Made everybody sick to their stomach. Don't know what happened to that speaker.

You probably just woke up everyones interest about that woofer.

Maybe someone from the past who might happen across this thread might be able to tease us some more.

Thanks for sharing with us Harvey, I always enjoy reading your posts!!!

Regards, Ron

[Harvey Gerst]

You probably just woke up everyones interest about that woofer.

Maybe someone from the past who might happen across this thread might be able to tease us some more.

Thanks for sharing with us Harvey, I always enjoy reading your posts!!!

Regards, Ron

Well, lemme see if I can add a little more information:
The lab and the sound room were at the east end of the building on Casitas, and one wall faced the street. The lab was kinda small and held the chart recorder, polar plotter and the various mics and prototypes. It had wires to both the large sound room, and to the roof (where we'd occasionally run free-field plots).

The sound room was pretty big (I don't remember the exact size) and Ed had set up this kinda big box in one corner of the room. I don't remember if it was a 15" or an 18" woofer.

All I remember is when you opened the door to the sound room and walked in, it was like suddenly being underwater; pressure everywhere. Not really a note; just pressure. You couldn't breathe and you could barely talk.

It was a interesting experience.

[scott fitlin]

Actually, no. Pretty much everything we came up with went into production. Except one.

I remember Ed May built a woofer that put out a ton of pure bottom end without much distortion. He played a 27 Hz sine wave through it, and it was like your head was instantly pressurized; you couldn't talk or hardly breathe. Made everybody sick to their stomach. Don't know what happened to that speaker.

Interesting! Ed May.

Harvey, what is it that made certain yesteryear drivers have such viscious bottom end? Especially that super fast transient attack that older JBL, Altec, and Gauss woofers had?

[louped garouv]

sounds like sitting in a SPL competetition bass car...


Wow...

[Harvey Gerst]

Interesting! Ed May.

Harvey, what is it that made certain yesteryear drivers have such viscious bottom end? Especially that super fast transient attack that older JBL, Altec, and Gauss woofers had?

A very tight magnetic structure, a small gap, a lot of copper/aluminum wire stuffed in that gap, and a relatively light, stiff cone.

[00Robin]

A very tight magnetic structure, a small gap, a lot of copper/aluminum wire stuffed in that gap, and a relatively light, stiff cone.

Sorry for the effusive gushing,but anything you post,Harvey,IS fascinating. Makes me wish I had been there during those days. At least I'm listening to what you built back then everyday and right now even. Were all you guys from and still in Texas? Does the super dry air of the western states and then the humidity of Michigan cause problems with the older Altec's?
Just wondering since I had to move back to Michigan after 30 glorious years in Wyoming and Montana.

[Harvey Gerst]

Sorry for the effusive gushing,but anything you post,Harvey,IS fascinating. Were all you guys from and still in Texas?

I moved to Texas from L.A. in 1978. Ed May worked at Frazier/May in Dallas before he went to work at JBL. I first met Ed when he went to work at JBL on Casitas. I was at JBL several years before Ed joined us. Ed replaced Bill Burton as Chief Engineer when Bill started Transducers Inc., a subsidiary of JBL, making high intensity sound systems.

[scott fitlin]

A very tight magnetic structure, a small gap, a lot of copper/aluminum wire stuffed in that gap, and a relatively light, stiff cone.

I love the woofers, high efficiency LF woofers of the 70,s and 80,s.

Im getting the sound I desire/crave, from brand new GPA Altec 416-8C,s VOTT loaded.

I have tried, in vain, to get into more modern, higher power handling speakers. All to no avail.

I still use six JBL 2395/2441 lenses, and 1 Crown D-150A powers all six horns, and its stunning what just a few watts will do with these.

I still use JBL 2240,s in scoop cabinets, and although not true sub woofers, they sound great, and again, what they do with relatively little power........