Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Planars & Exotics ESL's, planars, and alternative technologies

What are these ribbon drivers?
What are these ribbon drivers?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 31st January 2016, 10:06 PM   #1
cowanrg is offline cowanrg  United States
diyAudio Member
 
cowanrg's Avatar
 
Join Date: Apr 2002
Location: Lafayette, CO
Send a message via AIM to cowanrg
Default What are these ribbon drivers?

I came across someone selling these speakers locally and I have no idea what they are. Does anyone recognize them? I'm not sure if they're a DIY effort or an older production driver. Pictures aren't great because he didn't have a light on and it was hard to get a good picture without light.

Here's the whole speakers (in two parts):

Click the image to open in full size.

close-up of tweeter:

Click the image to open in full size.

another view of front of tweeter:

Click the image to open in full size.

back of driver:

Click the image to open in full size.

The tweeters are 23"x5" overall and there are two a side. The Boston Acoustics drivers were added later, the white/clear cone drivers were what came in the speakers. Does anyone recognize these or are they a really nice DIY speaker?
  Reply With Quote
Old 31st January 2016, 10:10 PM   #2
scholl is offline scholl  United States
diyAudio Member
 
Join Date: Dec 2012
Stratherns from the 70s
  Reply With Quote
Old 31st January 2016, 10:29 PM   #3
jacco vermeulen is offline jacco vermeulen  Netherlands
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
StratheArn, the ribbon unit is the MRHF.

(as used by Arnold Nudell, aka EMIRM, and a bunch of others)
  Reply With Quote
Old 31st January 2016, 10:36 PM   #4
cowanrg is offline cowanrg  United States
diyAudio Member
 
cowanrg's Avatar
 
Join Date: Apr 2002
Location: Lafayette, CO
Send a message via AIM to cowanrg
Ah, very cool. What would be the going price for a set of 4 of them you think?
  Reply With Quote
Old 31st January 2016, 10:54 PM   #5
cowanrg is offline cowanrg  United States
diyAudio Member
 
cowanrg's Avatar
 
Join Date: Apr 2002
Location: Lafayette, CO
Send a message via AIM to cowanrg
Quote:
Originally Posted by jacco vermeulen View Post
StratheArn, the ribbon unit is the MRHF.

(as used by Arnold Nudell, aka EMIRM, and a bunch of others)
also, what's the "MRHF"?
  Reply With Quote
Old 1st February 2016, 01:12 PM   #6
jacco vermeulen is offline jacco vermeulen  Netherlands
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
The name of the ribbon unit in your loudspeaker.

Strathearn developed/made it, used it in their own loudspeaker, also manufactured them for other audio companies.
Arnold Nudell used the unit in his late '70s Infinity loudspeaker model, renamed the Strathearn model to EMIRM.


(MRHF is short for mid-range/high-frequency)
Attached Images
File Type: jpg Infinity-QRS.jpg (62.3 KB, 381 views)
  Reply With Quote
Old 1st February 2016, 03:23 PM   #7
cowanrg is offline cowanrg  United States
diyAudio Member
 
cowanrg's Avatar
 
Join Date: Apr 2002
Location: Lafayette, CO
Send a message via AIM to cowanrg
Ah OK, I should have searched more. Strathearn doesn't come up with a whole lot, neither does EMIRM. They seem pretty rare actually. Seems like a good find. Now I just need to figure out if it's a good deal :-) Thanks for the help.
  Reply With Quote
Old 1st February 2016, 03:26 PM   #8
billshurv is offline billshurv  United Kingdom
diyAudio Member
 
billshurv's Avatar
 
Join Date: Mar 2014
What are these ribbon drivers?
Quote:
Originally Posted by jacco vermeulen View Post
Strathearn developed/made it, used it in their own loudspeaker, also manufactured them for other audio companies.
Arnold Nudell used the unit in his late '70s Infinity loudspeaker model, renamed the Strathearn model to EMIRM.

So did the EMIRM begat the EMIM?
  Reply With Quote
Old 1st February 2016, 04:51 PM   #9
jacco vermeulen is offline jacco vermeulen  Netherlands
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Could be.

The EMIT was a further development by Mr Christie, original design was by Mr. Von Recklinghausen.
Both MRHF and EMIM are not true ribbons, but planar magnetostatic.
Very likely that Mr. Christie also used the MRHF driver as a start, to develop the EMIM.

(also a fair chance that it was born of logistic necessity after the Dublin drama of the late '70s (what other way is there for the Irish but dramatic)
  Reply With Quote
Old 3rd February 2016, 05:20 AM   #10
lowmass is offline lowmass  United States
diyAudio Member
 
Join Date: Jan 2016
I have a bit of experience with the Stratherns and even have replaced the diaphragms on a few pr. They are capable of very good performance when used properly. Easily competing with modern planer magnetics. In stock trim they use some very low density fiber board as damping material for the tensioned film diaphragm and the perforated aluminum on the back sides holds some fiberglass in place to give some further diaphragm loading. Check to be sure the magnets are all in place and none broken loose. the build is quite fragile so be carful poking around. Very good plainer sound from about 400hz on up to approx 18khz. they have a couple bumps in freq response cant remember where exactly but its up around 5-10 khz. Typical dual slot planer peaks I believe. Many people used a trap circuit or two to tame. Early units had slightly thinner foil traces than the latter units but not a significant perf difference. Make sure they come with the transformers. If in good condition you would pay easily 500 pr or more for a modern driver to compete.
  Reply With Quote

Reply


What are these ribbon drivers?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
SA 8526 Ribbon drivers earcatcher PA Systems 2 27th October 2016 10:42 PM
Ribbon Drivers in Headphones fidelia91 Headphone Systems 0 19th November 2014 11:35 PM
FS; 2 JVC RIBBON DRIVERS homemade Swap Meet 3 13th December 2010 07:46 PM
Davis Drivers and Ribbon Tweeter jleaman Multi-Way 2 28th May 2005 09:05 AM
Repairing ribbon drivers and TCO tiroth Multi-Way 7 25th May 2004 11:00 AM


New To Site? Need Help?

All times are GMT. The time now is 12:27 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki