How to build your own Jecklin disk using parts supplied from Amazon

The Jecklin disk is an acoustic baffle designed to make hyperrealistic stereo recordings using semi HRTF-like signals. It is the invention of Jürg Jecklin and we make use of it as a basis for unobstrusive acoustic / classical music location recording, along with other techniques.

Building your own Jecklin disk is simple and can be done with some easy to find materials. Here is our current list of preferred parts with links* to the products on Amazon:
  • At least one mounting plate / small cheese bar, wide enough to accomodate the upper rod of a microphone stand (i.e.: 2 cm).
  • Perforated disks. We use two 16" disks, becuase we have not (yet) found a secure symmetrical way to attach the whole thing to a stand using only one.
  • At least two 7.7" cheese bars. We have built a disk that can take two sets of bars, and more bars can be concatenated if more seperation is needed. A pair of telescopic selfie sticks can be used instead, but then you need adequate clamps to attach microphones supports. We have tried both but tend to prefer the cheese bars for less total weight. In the case of our bar and current microphone setup, the right place for the mic holder is over the fourth 1/4" hole from the center. This gives us 36cm between capsules and a 35 degree angle on each side.
  • Open-cell rubber foam tape of varying thickness with adhesive backs can be used to deaden the disk so as to produce the desired acoustic shawdowing requiered for the Jecklin effect and to mitigate reflections. We have used 0.5x2", 0.5x1", 0.25x0.5" and others. The traditional way is about an inch or more of foam on each side. You can try felt or other materials if you wish. Don't leave the disks bare, otherwise sound will leak right through the holes, there will be no Jecklin effect and you will also get some nasty reflections.
  • 3/4" to 1/4" adapters will allow you to attach microphone holders to the bars (or clamps).
  • 1/4" D-ring screws will help hold the disks and the mounting plate together, especially when the bars are not attached.
  • 2 (or more) M12 to 1/4" adapters allow attaching the bars to the mounting plate through holes in the disks. These are a critical parts as they hold everything together and carry the weight of the bars and microphones.
  • A pack of rubber washers help coax the cheese bars into the desired positions so the holes are pointing in the right direction, and can help avoid some shock tranmission from the central part of the structure to the bars, even if using telescopic sticks where there is no need to point them.
Suggestions:
  • Go slow. Find the right position for the bars on the disks depending on the length of your microphones and their holders or suspension hardware. You will want to have the capsules right over the center of the disks. Only when you are sure of the best position should you start stickling foam onto the disks.
  • Try stuff. It's supposed to perform best with omnidirectional SDC microphones, but it can also work with cardioid, "open" cardoid or subcardioid and even variable-pattern microphones. If you use microphones with some directionality you might be able to vary the SRA (Stereo Recording Angle) a bit. With omnis seperated by 36cm (each somewhat less than 18cm from their side of the baffle because of the inter-disk distance) it's hyperrealistic to about 80 degrees and tops at 90 degrees.

*These links might help us through a partner program but will not cost you extra.

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