• Item: DIY planar magnetic and open baffle woofer towers  
  • Type: dipole speakers  
  • Posted: 23 April 2017  
  • Builder: Few  
  • Country: United States  
  • Comments: 8  

DIY planar magnetic and open baffle woofer towers

The midrange/tweeter towers each comprise four DIY planar magnetic drivers. The tweeter conductor is centered between the midrange conductors in a horizontal MTM arrangement. Each planar was made with 13 micron kapton tape attached to stretch-wrap surrounds. The conductive trace is 10 micron aluminum foil cut with a Silhouette computer-controlled cutter. NdFeB magnets are glued to perforated steel sheets to provide a single-sided magnet structure.

The woofers are Dayton Reference Series 8" drivers. The towers' front baffles were made from kerfed MDF wrapped in fiberglass. The rear spine was made with laminated spruce, and half of a PVC pipe (to form the rear curve) all wrapped in fiberglass.

Comments

  • mwmkravchenko
  • 24 April 2017 at 07:35AM
  • Beautiful combination of form function and good old materials engineering.

    Hoping you many years of listening.
  • jorgep
  • 24 April 2017 at 08:23AM
  • more pics and detail, please
  • jorgep
  • 24 April 2017 at 08:23AM
  • extraordinary
  • Few
  • 25 April 2017 at 11:21AM
  • Thanks for the kind words. For some more details on construction and measurements, and some more photos, you can take a look at the thread on diyaudio:

    http://www.diyaudio.com/forums/planars-exotics/301091-diy-planar-magnetic-open-baffle-woofer-array.html

    I'm a newb on this site and only saw capacity for five photos when I posted the project.
  • Jazzman53
  • 6 July 2017 at 04:54PM
  • Beautiful project, Few. Your skills are an inspiration.
  • Few
  • 5 August 2017 at 09:17PM
  • Thanks, Jazzman53. I very much appreciate the support. I hope I don't need another decade for the next bit of progress!

    By the way, since your handle implies an affection for jazz, I'll add that I just completed an MS microphone construction project. It inspired me to pull the ol' tenor sax out of mothballs as a combined mic and speaker test. I'm quite pleased! Not Pleased by my playing, so much, but the mic/speaker combination sounded as I thought they should, having just created the recording. Quite satisfying!
  • Jon
  • 5 February 2019 at 07:06AM
  • Fantastic! This must be one of the nicest Diy speaker build out there!

    Did You use a transfersheet when making the tracks on the Silhouette?
  • Few
  • 7 May 2020 at 10:21PM
  • Apparently I need to poke around here more than once a year! Sorry for the delayed thanks and answer to your question, Jon. The Silhouette cuts according to a pattern I created using Adobe Illustrator. From within Illustrator, you can send the pattern to the Silhouette, set the cutting parameters (speed, pressure, type of material being cut) and then click go.

    The conductive traces were made using aluminum foil with a paper backing, intended for use as a sandwich wrap. The Kapton tape's adhesive sticks well to the aluminum, and the paper helps prevent tears while cutting. Removing the paper after each cut is a little tedious but not too bad.

    The speakers have been in continuous operation for three years or so. I've had to redo one or two solder joints, and one or two glue joints, but they've been very robust overall. I've enjoyed them so much I've since worked only on speakers that would not compete with them for a spot in the living room! It's time to do some room treatment, though.

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