DIY Ribbon speakers ?? - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

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

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 6th June 2001, 09:24 AM   #1
diyAudio Member
 
promitheus's Avatar
 
Join Date: Jan 2001
Location: Germany
In the new AudioXpress magazine there is a new article about making a ribbon mid/tweeter. It looks very good and I was interested in finding a few thing online. Does anybody have more information on the subjects or some books to propose ?
Thanks in advance
Ilias
  Reply With Quote
Old 6th June 2001, 03:07 PM   #2
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
Ilias,
I searched high and low for DIY ribbon information a few years ago. This is the only (semi-useful) link I found:
http://www.geocities.com/ResearchTri...mag/index.html
If you've got a construction article, it may be of more use than the majority of the stuff on the web. There seem to be a lot of people out there who can't tell the difference between a ribbon and a planar magnetic. Ribbons, by definition, are unnattached (except at the ends) in a transverse magnetic field, whereas planar magnetics are fixed at the sides and have a front-to-back magnetic field--usually supplied by multiple strips of magnets. Note that even some of the high-end manufacturers use the wrong terminology (e.g. Genesis referring to their tweeters as 'ribbons') because ribbons have such cachet in the market place, and the majority of consumers don't know the difference. You have been warned.
There are several problems to be overcome in a true ribbon driver:
1) Cost of the magnets--if you intend to do a long driver, you'll be spending hundreds on magnets alone
2) Cavity resonance--the fact that the membrane is down in a hole gives a peak in the response
3) Resistance--if you want a direct drive ribbon, you'll need very thin metal for the ribbon (probably aluminum, although there's no reason you can't use other metals--just watch out for mass), which leads to...
4) Availibility of ribbon material--aluminum measured in microns isn't easy to come by, although I did run across one hint that sounded interesting->use the aluminum foil off the back of gum wrappers
Since I wanted a line source midrange to match my Magneplanar ribbon (a true, direct-drive ribbon), I wanted to build something at least five feet long. I beat my head against the wall for a while, then gave up and bought a pair of Bohlender-Graebener RD-75's. Note that the RD-75's are planar magnetics, not true ribbons.
Planar magnetics are easier to build than true ribbons, but are subject to the same problems.
All that said, I have since acquired some magnet stuctures from mainframe disk drives with some prodigious magnets. I am considering building a more point-source oriented true ribbon more like the Orca Raven tweeters (using gum wrapper aluminum foil--anyone know what brand sounds best?...ahem...) as a rainy day project to go with a pair of transmission line midranges (something I've always wanted to try), and probably T-L woofers. For those who've never tried 'em, transmission line subs are capable of excellent sound reproduction, although I don't know whether they will do as well for midrange use.

Grey
  Reply With Quote
Old 6th June 2001, 03:20 PM   #3
diyAudio Member
 
Join Date: Feb 2001
Location: Lublin/Poland
This is not exactly what you are looking for
but you might have a look at
http://www.proinco.net/staff/mogens/lafolia/

Greg
  Reply With Quote
Old 7th June 2001, 12:17 AM   #4
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
Two quick comments on the site Greg posted:
1) As an alternative to cutting the aluminum foil with blades, it's easy to etch aluminum in much the same way that you'd do a circuit board. That way you could do a layout and make sure that the lines were straight before etching, whereas cutting tends to be an all-or-nothing process.
2) The bass membrane should be corrugated also. The corrugation is to prevent standing waves.
I once built a Magneplanar-style planar driver in an hour, simply by using a piece of plastic and gluing ordinary copper wire to it. It worked first time. (As well it should--the theory is simple enough!) I didn't pursue it, as the ribbon tweeter was the thing I was after at the time, not the bass panels. Anyway, the point is--don't be afraid to use copper wire in place of aluminum if the mood takes you.

Grey
  Reply With Quote
Old 7th June 2001, 12:40 AM   #5
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
Another thing I tried once that worked:
A friend managed to break the leads off of both ends of a Wondercap (metallized polypropylene) and was going to throw it away. I snagged it and threw it in my junk box. Later, I unwound the cap and cut various widths of membrane from it. For magnets, I used the big round ceramic magnets off the back of garden variety 12" woofers--two of them, oriented north to south with a wooden spacer.
Narrower mambranes give you higher R and greater efficiency, due to the magnetic field lines being able to bridge the gap more easily. (I did *not* try any sort of flux return bridging the outside poles of the magnets, but it wouldn't be hard to arrange.) They also give you better dispersion for higher frequencies.
Wider membranes move more air.
The way I had it rigged was as a true ribbon, i.e. fastened on the ends, unsupported in the middle, with the magnets on each side. It was easy to make and fun to play with. I may go back and piddle with it some more some day.

Grey
  Reply With Quote
Old 7th June 2001, 03:56 PM   #6
tvi is offline tvi  Australia
diyAudio Member
 
tvi's Avatar
 
Join Date: Apr 2001
Location: Moonee Ponds, Vic, Australia
You may find the following two links handy when building ribbons
Copper Foil Tape (3M)
http://au.rs-c.dk/servlet/dk.stibo.m...duleId=5035415

Clear polypropylene carton sealing tape
http://www.pro-am.com/Catalog/Exec/p...product_id=686

might also be handy for DIY cables?
  Reply With Quote
Old 8th June 2001, 08:48 PM   #7
diyAudio Member
 
Join Date: Jun 2001
Location: Netherlands
Default The Ribbon Loudspeaker Circuit

The following link may be of interest for you. There is some information on Ribbons there.

http://www.audiocircuit.com/9109-rib...t/9109IMAI.htm

  Reply With Quote
Old 23rd January 2006, 08:16 AM   #8
diyAudio Member
 
Join Date: Jun 2005
Location: Neuss, Germany
Default Ribbon DIY

I assembled a DIY Ribbon last month - look at "Lautsprecher" at http://www.michaelgaedtke.de/
__________________
Michael
  Reply With Quote
Old 24th January 2006, 06:51 PM   #9
beamnet is offline beamnet  Netherlands
diyAudio Member
 
beamnet's Avatar
 
Join Date: Jun 2004
Location: enschede
Send a message via MSN to beamnet
are you going to share the rusults with us? how doesit sound? do you have some specs?

Bas
  Reply With Quote
Old 24th January 2006, 09:17 PM   #10
diyAudio Member
 
Join Date: Jun 2005
Location: Neuss, Germany
Here comes the SPL measurement (without calibration; this is not at 2.83 V/8 Ohm, which doesn't make much sense at som 0.1 Ohm).
__________________
Michael
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
does anyone recognize these ribbon speakers? cowanrg Planars & Exotics 9 15th November 2007 09:20 PM
Marantz ribbon speakers I am the Walrus Multi-Way 2 29th August 2005 07:10 PM
budget ribbon bookshelf speakers xstephanx Multi-Way 12 17th April 2005 01:15 AM
Ribbon speakers martioz Multi-Way 0 20th January 2003 12:55 AM


New To Site? Need Help?

All times are GMT. The time now is 01:02 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2