Planar speaker - first try - 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 29th August 2010, 08:08 PM   #1
bentl is offline bentl  Norway
diyAudio Member
 
Join Date: Apr 2009
Location: Norway
Default Planar speaker - first try

Hi,

I have decided to built a magnetic driven planar speaker.

Got most of the parts, and the design is illustrated below. A perforated steel plate as I have used in my ESL projects, with 10x10x40mm neo magnets. A alu frame in 1/2" x 1/2" square alu tube provides stiffness and spacing between diaphragm and magnets (distance will be 2,7mm + 1mm vhb tape.

Image.jpg

Diaphragm will be 6micron mylar, with 9mm wide CPC alarm tape as conductor (0,6 ohms/meter resulting in a 5,4 ohm dc resistance I should imagine.

Horisontal spacing between magnets will be 15mm, and 10mm vertical spacing.

Outer dimensions of the frame will be 190mm wide and 1000mm high.
There will be 8X18 = 144 magnets pr speaker.

As the back plate is bigger than the diaphragm, it will be easy to mount baffles, and easy to add a ribbon tweeter if I should decide to do so later.

I am very exited by this project, it should be easy to build and hopefully give more satisfying results than my ESL attempts has given so far.

Any comment to my idea? Should i make it wider, bigger/smaller distance between magnets, distance between magnets and diaphragm?

Theese magnets cost a fortune, so I am reluctant to increase the number of magnets in the first test (I have 205 in stock)

All that remains now, is to unite theory with practice and see how it turns out!

Regards,

Bent
  Reply With Quote
Old 31st August 2010, 07:24 PM   #2
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
THat looks promising, with alll those powerfull magnets. by the way how did you get the tape and what is the width of the tape and most of all where did you get it. i looked like everywhere to get aluminium tape in small width also in the security branche but it looks like they dont use it anymore or something. i still got 4 perf plates with all the magnets of a Magnepan wich i would like to use for something after all the searching


sorry you metnion the width of the tape but with 0,6 ohm a meter this is nice thing foil
  Reply With Quote
Old 31st August 2010, 07:45 PM   #3
bentl is offline bentl  Norway
diyAudio Member
 
Join Date: Apr 2009
Location: Norway
Hi,

I got the tape from cpc.co.uk by recommendation from mr JAMESBOS
They ship internationally but have a rigid ordering system with prepayment.
5 rolls costed me 5 GBP and 18GBP including freight

The tape is 0,006 thick, 9mm wide. I haven´t opened the tape yet, so I am unsure if it comes with a liner or not. If it has a liner it can be rolled out and splitted in half.

I have decided to order some more magnets and make the speaker a bit bigger, and have a few magnets in spare for some ribbon tweeters.

Regards,
Bent
  Reply With Quote
Old 31st August 2010, 08:53 PM   #4
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
splitted in half ? what do you mean, so the tap is 4.5 mm ? or. dont know what a liner is i amfraid explain
  Reply With Quote
Old 1st September 2010, 02:33 AM   #5
diyAudio Member
 
chinsettawong's Avatar
 
Join Date: Jun 2006
Hi Bentl,

It looks like a fun project. Please keep us updated.

Wachara C.
  Reply With Quote
Old 1st September 2010, 07:09 AM   #6
bentl is offline bentl  Norway
diyAudio Member
 
Join Date: Apr 2009
Location: Norway
Quote:
Originally Posted by WrineX View Post
splitted in half ? what do you mean, so the tap is 4.5 mm ? or. dont know what a liner is i amfraid explain
Hi,

tape is 9mm wide, but if it has a peelable backing/protection one can lay it out on the table and split it in half with a knife to get 4,5mm...and then run 2 lengths.

Bent
  Reply With Quote
Old 1st September 2010, 10:05 AM   #7
WrineX is offline WrineX  Netherlands
diyAudio Member
 
WrineX's Avatar
 
Join Date: Mar 2004
Location: Den Haag
Thx for the explanation. wel the knife thing is a horror i used it on normal aluminium tape to cut it in small tapes. did not really liked the work and the result. but 0.6 ohm a meter for a 9 mm width tape is also really nice so im gone get a look at the site Many THx. and keep us updated im really curious
  Reply With Quote
Old 1st September 2010, 07:14 PM   #8
bentl is offline bentl  Norway
diyAudio Member
 
Join Date: Apr 2009
Location: Norway
Hi,

uploading a new illustration on how it is going to be built. I guess I will make the trim out of pine, and wax and polish it in a dark wood colour.

Planning on making a inner frame that holds the speaker grill cloth, and fit it with magnets so it snaps to the perforated plate.

I am planning on casting the base in concrete, the type used on bathrooms. It's on sale this week ;-)

Image2.jpg

I might have to reduce the widt of the speaker element in order to fit a ribbon tweeter.

Regards
Bent
  Reply With Quote
Old 1st September 2010, 07:25 PM   #9
diyAudio Member
 
bolserst's Avatar
 
Join Date: Jun 2005
Location: Fort Worth, Texas
Quote:
Originally Posted by WrineX View Post
Thx for the explanation. wel the knife thing is a horror i used it on normal aluminium tape to cut it in small tapes. did not really liked the work and the result. but 0.6 ohm a meter for a 9 mm width tape is also really nice so im gone get a look at the site Many THx. and keep us updated im really curious
For cutting aluminum tape and thin diaphragm material I have found rotary razor blade cutters to work well, cutting smoothly in straight lines without snagging, wrinkling or tearing.
Attached Images
File Type: jpg rotary_cutter.jpg (33.6 KB, 2271 views)
  Reply With Quote
Old 1st September 2010, 08:24 PM   #10
bentl is offline bentl  Norway
diyAudio Member
 
Join Date: Apr 2009
Location: Norway
Yes, I got some of those. search for "olfa rotary" on the ebay. Quite cheap and very useful.

And VERY sharp, mind the fingers when replacing the blade!
  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
Full range planar speaker using neo magnets JAMESBOS Planars & Exotics 335 5th April 2014 01:28 PM
Anybody seen this type of planar speaker? WrineX Planars & Exotics 18 20th August 2012 02:36 AM
My DIY planar speaker! Matt MacBeth Planars & Exotics 5 1st July 2010 09:29 AM
need help picking a planar speaker lochness Multi-Way 5 30th May 2007 08:42 AM
planar 25 vs planar 3 GAK Analogue Source 2 30th January 2004 03:38 PM


New To Site? Need Help?

All times are GMT. The time now is 11:06 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