ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 2 [All]   Go Down

Author Topic: Who was using ferrofluid in 1973?  (Read 1387 times)

Michael {Bink} Knowles

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4384
Who was using ferrofluid in 1973?
« on: August 31, 2019, 02:02:52 pm »

I'm trying to find out who pioneered the use of ferrofluid as a cooling agent in the voice coil gap of compression drivers, which was the first application. A bunch of books and articles say that 1973 was the year, but they don't name the person or company.

Logged

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Online Online
  • Posts: 20467
  • Wichita, Kansas USA
Re: Who was using ferrofluid in 1973?
« Reply #1 on: August 31, 2019, 03:22:42 pm »

Binkster!  You're back!

My memory says "TAD" but I'm not certain that is correct.

1973 is a lot of brain cells ago...
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

John Roberts {JR}

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 16397
  • Hickory, Mississippi, USA
    • Resotune
Re: Who was using ferrofluid in 1973?
« Reply #2 on: August 31, 2019, 05:25:00 pm »

Have you tried asking the manufacturer of ferro-poop...?

JR
Logged
Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

Mike Caldwell

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1443
  • Covington, Ohio
    • Mike Caldwell Audio Productions
Re: Who was using ferrofluid in 1973?
« Reply #3 on: September 01, 2019, 07:24:34 am »

NASA invented it in the 60's.
Not sure who first had the idea to put it in a voice coil gap.

Justice C. Bigler

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 2268
  • Somewhere between the Atlantic and Pacific
    • My homepage
Re: Who was using ferrofluid in 1973?
« Reply #4 on: September 01, 2019, 01:18:07 pm »

NASA invented it in the 60's.
Not sure who first had the idea to put it in a voice coil gap.
Probably some NASA engineer when he was home brewing his HiFi stereo system at home?
Logged
Justice C. Bigler
www.justicebigler.com
Head Audio/A1 Blue Man Group North American Tour

Michael {Bink} Knowles

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4384
Re: Who was using ferrofluid in 1973?
« Reply #5 on: September 01, 2019, 03:31:13 pm »

Have you tried asking the manufacturer of ferro-poop...?

JR

Not yet. I understand Ferrofluidics in Burlington, Mass, put out a sample kit in 1973, so they're definitely on the early side.
https://www.czferro.com/ferrofluid-history
Logged

Michael {Bink} Knowles

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4384
Re: Who was using ferrofluid in 1973?
« Reply #6 on: September 01, 2019, 03:34:22 pm »

... And this patent says "the 'Newsreports' section in Electrimechanical Design, October 1973 describes the use of Ferrofluids to seal the space between the poles of a loudspeaker."

https://patents.google.com/patent/US4017694A/en
Logged

Michael {Bink} Knowles

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4384
Re: Who was using ferrofluid in 1973?
« Reply #7 on: September 03, 2019, 01:20:55 pm »

This Ferrotec page says "The first commercial use of ferrofluid in loudspeakers was 46 years ago, in 1973." I'll shoot them an email and ask who it was.


http://www.loudspeakerindustrysourcebook.com/united-states/bedford/liscategories/ferrotec-28usa29-corporation
Logged

Douglas R. Allen

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1022
Re: Who was using ferrofluid in 1973?
« Reply #8 on: September 03, 2019, 02:35:33 pm »

I'm trying to find out who pioneered the use of ferrofluid as a cooling agent in the voice coil gap of compression drivers, which was the first application. A bunch of books and articles say that 1973 was the year, but they don't name the person or company.

I seemed to remember Radio Shack using it in their speakers back in the early/mid 1970's. I had a set of Mach 1's when they first came out and they did mention liquid cooling that I believe they said was oil but that was a few years ago. :-\

Douglas R. Allen
Logged

Michael {Bink} Knowles

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4384
Re: Who was using ferrofluid in 1973?
« Reply #9 on: September 03, 2019, 03:03:12 pm »

Ferrotec responded to my email in 36 minutes! Wow.

Marketing specialist Vanessa Rene at Ferrotec says that Bob Berkowitz of Acoustic Research began studying ferrofluid in 1972, using it to damp resonance of a tweeter. Fred Becker and Lou Melillo of Becker Electronics were also early adopters in 1976. Panasonic was the first Asian manufacturer to put ferrofluid in commercial loudspeakers, in 1979. The field grew rapidly in the early '80s, with Meyer Sound, Apogee Sound and many more jumping in.

Other archival sources show that Dana Hathaway of Epicure in Massachusetts was using ferrofluid for tweeter damping in '74, and he noticed the cooling mechanism.

By 1979, Showco was putting ferrofluid in woofers for the cooling effect.
https://books.google.com/books?id=fAEAAAAAMBAJ&pg=PA61
Logged

Rick Earl

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 310
Re: Who was using ferrofluid in 1973?
« Reply #10 on: September 03, 2019, 03:13:21 pm »

I am aware of EV using it, but not sure of timeline.
https://www.electrovoice.com/binary/DH1202%20EDS.pdf
Logged

John Roberts {JR}

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 16397
  • Hickory, Mississippi, USA
    • Resotune
Re: Who was using ferrofluid in 1973?
« Reply #11 on: September 03, 2019, 04:31:56 pm »

Ferrotec responded to my email in 36 minutes! Wow.

Marketing specialist Vanessa Rene at Ferrotec says that Bob Berkowitz of Acoustic Research began studying ferrofluid in 1972, using it to damp resonance of a tweeter. Fred Becker and Lou Melillo of Becker Electronics were also early adopters in 1976. Panasonic was the first Asian manufacturer to put ferrofluid in commercial loudspeakers, in 1979. The field grew rapidly in the early '80s, with Meyer Sound, Apogee Sound and many more jumping in.

Other archival sources show that Dana Hathaway of Epicure in Massachusetts was using ferrofluid for tweeter damping in '74, and he noticed the cooling mechanism.

By 1979, Showco was putting ferrofluid in woofers for the cooling effect.
https://books.google.com/books?id=fAEAAAAAMBAJ&pg=PA61
Sounds like the right people to ask... I had a pair of AR4 speaks back in day,,,,

I suspect Rat Shack may have tried to use FF as a bandaid for small drivers that released their smoke too often.

JR
Logged
Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

Doug Fowler

  • Member since May 1995, 2nd poster on original LAB, moderator on and off since 1997, now running TurboMOD v1.826
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1696
  • Saint Louis, MO USA
Re: Who was using ferrofluid in 1973?
« Reply #12 on: September 03, 2019, 09:29:06 pm »

Surprised no one has at least mentioned Community yet.
Logged
"It's got electrolytes.  It's got what plants crave."

Riley Casey

  • Hero Member
  • *****
  • Online Online
  • Posts: 1351
Re: Who was using ferrofluid in 1973?
« Reply #13 on: September 03, 2019, 09:39:01 pm »

All the Community horns I remember from the FRC, Leviathan and plastic radial horn days were strictly bring your own drivers.

Surprised no one has at least mentioned Community yet.

Chris Hindle

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 1646
  • Montreal, Quebec, Canada, Earth, Sol System,......
Re: Who was using ferrofluid in 1973?
« Reply #14 on: September 04, 2019, 12:03:53 am »

All the Community horns I remember from the FRC, Leviathan and plastic radial horn days were strictly bring your own drivers.
Ya, I had 2441's on Community BRH90 large format horns.
I think the first time I saw FF was with an EV driver. DH-1A maybe?
Chris.
Logged
Ya, Whatever. Just throw a '57 on it, and get off my stage.

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Online Online
  • Posts: 20467
  • Wichita, Kansas USA
Re: Who was using ferrofluid in 1973?
« Reply #15 on: September 04, 2019, 12:15:21 am »

Surprised no one has at least mentioned Community yet.

The spec sheets online for the VHF100 and M200 are dated 1999 and make no mention of Ferrofluid... BUT... spec sheets for loudspeakers *do* mention Ferro, specifically the SLS9xx series (which use those drivers).  Anyone remember when the SLS launched?  I'm pretty sure it was after 1979...
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

lindsay Dean

  • Classic LAB
  • Hero Member
  • *
  • Offline Offline
  • Posts: 638
Re: Who was using ferrofluid in 1973?
« Reply #16 on: September 04, 2019, 01:32:21 pm »

Actually Radio Shack used ferrofluid in the Mach 1 series of loudspeakers.
 to my memory those things sounded pretty good for what they were
Logged
"A mans got to know his limitations"
     and Pray for higher guidance

John Roberts {JR}

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 16397
  • Hickory, Mississippi, USA
    • Resotune
Re: Who was using ferrofluid in 1973?
« Reply #17 on: September 04, 2019, 02:45:19 pm »

The list of who didn't use ferro fluid (ever) is probably shorter than the list of who did, but that wasn't Bink's question.

JR
Logged
Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

ProSoundWeb Community

Re: Who was using ferrofluid in 1973?
« Reply #17 on: September 04, 2019, 02:45:19 pm »


Pages: 1 2 [All]   Go Up
 



Page created in 0.096 seconds with 24 queries.