Audio Discussion > DIY

Yet another ESL project

(1/4) > >>

jazzman53:
The insanity continues... more to come:

Kingman:
WOW!!!! Looking good Charlie! An updated electrostatic panel.  Details????

jazzman53:
This project is a segmented wire-stator type electrostatic speaker. 

The photo shows my stretching jig and stator wires being stretched about 1%.   Stretching the copper wires to plastic deformation renders them perfectly straight and also work hardens the metal such that the wires remain straight when the tension is relaxed. 

The stator wires will be supported in the speaker by an wooden lattice frame that will look somewhat like a ladder; consisting of side rails, two center rails and eighteen horizontal rung supports.

There are 90 wires total, which will be segmented into (15) 6-wire groups.  The center wire group will be directly coupled to the amplifier/step-up transformers; receiving the full frequency band above 200 Hz.  From the center outward, the paired wire groups to the left and right of center will receive progressively less treble.  This is accomplished by inserting resistors between the segments, which then couples with the wires' capacitance to form a first order filter that attenuates the treble downward and imparts a small phase shift that bends the wavefront into a cylindrical shape. 

The effect is that the flat panel electrostat now projects a cylindrical rather than planar wavefront; giving wide dispersion.   The polar response will be far superior to a curved panel (like ML) and even better than most conventional speakers, while still retaining the  magical ESL sound.               

jazzman53:
BTW, I'm not smart enough to figure any of this out... but I have smart friends over at the DIY Audio Forum who provided me with an Excel spreadsheet calculator that does all the math. 

I just plug in the height & width of the panel, diaphragm-to-stator spacing, number of wire groups, and the low end cutoff frequency (where the woofer takes over) and the spreadsheet calculates the resistor values, max SPL, and frequency response curve.  Pretty cool! 

MacGeek:
Very nice.  I wish you lived near Pittsburgh so some of us could hear them.

Navigation

[0] Message Index

[#] Next page