Yet another project

Jazzman53 · « **on:** 26 Feb 2016, 12:31 am »

The insanity continues... more to come:

Davey · « **Reply #1 on:** 26 Feb 2016, 02:58 am »

Going to rack some audiophiles and stretch them 'til they relent?

Dave.

Jazzman53 · « **Reply #2 on:** 26 Feb 2016, 03:22 am »

YES!
50 lbs x 90 wires = 4,500 lbs... yikes!

JerryM · « **Reply #3 on:** 26 Feb 2016, 05:55 am »

Awesome.

Jazzman53 · « **Reply #4 on:** 26 Feb 2016, 11:24 pm »

Oh yeah, baby!

Davey · « **Reply #5 on:** 27 Feb 2016, 04:18 am »

Very very cool.

Dave.

rajacat · « **Reply #6 on:** 27 Feb 2016, 04:58 am »

Wow

! That looks dangerous.

SteveFord · « **Reply #7 on:** 27 Feb 2016, 12:01 pm »

So when are you going to quit tormenting us and put this stuff into production?
Everything I try and build turns into an ash tray!

Jazzman53 · « **Reply #8 on:** 28 Feb 2016, 12:34 pm »

Quote from: SteveFord on 27 Feb 2016, 12:01 pm

So when are you going to quit tormenting us and put this stuff into production?
Everything I try and build turns into an ash tray!

Well Steve,
I would soon starve if I had to build speakers for a living so I'll stick with my day job.

I am giving some thought though, to some ESL kits for the guys at next years' Carverfest. The challenge of course would be coming up with design that a bunch of drunks (myself included) could cobble together in a few days without getting themselves electrocuted.

For this case the only design that makes any sense would be a full range with a lower cutoff around 80Hz.

Anyways... I'm giving it some thought.

Jazzman53 · « **Reply #9 on:** 28 Feb 2016, 12:44 pm »

More info -- see the sketch below:

This project is a bi-amplified segmented wire-stator type, hybrid electrostatic speaker. A conventional woofer will do bass duties below 200 Hz.

The photo shows my stretching jig and stator wires being stretched about 1% elongation. 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.

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!

Jazzman53 · « **Reply #10 on:** 28 Feb 2016, 12:47 pm »

double post..

SteveFord · « **Reply #11 on:** 28 Feb 2016, 11:29 pm »

Pretty cool is right!
I won't be going to Carverfest but keep me in mind if you come up with a kit, please.

Jazzman53 · « **Reply #12 on:** 10 Mar 2016, 02:55 am »

Update 3/9/16:

Most of the wooden pieces for the wire support lattices are cut. A few minutes ago I dry fitted the interlocking pieces for one of them (see below).

I plan to spray apply a coat of a light stain and a coat of satin polyurethane (while assembled, not glued). And then re-assemble and glue the pieces together, over the wires, in the stretcher jig.

The stators must fit within the frame of my existing beam splitter speakers and they had to be rather thin to clear the beam splitter during install.

It's a lot of work but I think they will look much better than my current welding rod panels.

Hank · « **Reply #13 on:** 10 Mar 2016, 05:50 pm »

Interesting and NICE work. Did you use a dado blade set or a router jig or router table on the oak pieces? Be sure to put a good coat of poly on every exposed wood surface for long-term moisture protection.

Jazzman53 · « **Reply #14 on:** 10 Mar 2016, 06:44 pm »

I did not cut and profile each piece individually. Rather, I cut boards to net length and excess width, then planed them to thickness, then cut the dado slots on a router table, and then cut the surface profiles (45 deg angles) on the table saw. I then rip cut slices from the profiled boards to get the individual pieces.

gregfisk · « **Reply #15 on:** 12 Mar 2016, 01:42 am »

Quote from: Jazzman53 on 10 Mar 2016, 06:44 pm

I did not cut and profile each piece individually. Rather, I cut boards to net length and excess width, then planed them to thickness, then cut the dado slots on a router table, and then cut the surface profiles (45 deg angles) on the table saw. I then rip cut slices from the profiled boards to get the individual pieces.

That is a really smart way to do those pieces, they look really good! I have not seen your thread before, I will be looking for your posts from now on and look forward to your progress.

Greg

a.wayne · « **Reply #16 on:** 12 Mar 2016, 08:45 am »

Quote from: Jazzman53 on 10 Mar 2016, 02:55 am

Update 3/9/16:

Most of the wooden pieces for the wire support lattices are cut. A few minutes ago I dry fitted the interlocking pieces for one of them (see below).

I plan to spray apply a coat of a light stain and a coat of satin polyurethane (while assembled, not glued). And then re-assemble and glue the pieces together, over the wires, in the stretcher jig.

The stators must fit within the frame of my existing beam splitter speakers and they had to be rather thin to clear the beam splitter during install.

It's a lot of work but I think they will look much better than my current welding rod panels.

Damn Jazz , I see you are still still at it ....

Peter J · « **Reply #17 on:** 12 Mar 2016, 04:01 pm »

I've read this thread a couple of times and you know what? I really don't know how an electrostatic loudspeaker works!

I'm intrigued though, by both method and theory, so I'll follow along with interest. Who knows, maybe I'll pick up some knowledge along the way.

Thanks for posting Jazzman, your work is very cool. For me anyway, you couldn't post too much about it. Is there a place on DIY audio where the e-stat people hang out?

Don_S · « **Reply #18 on:** 12 Mar 2016, 04:20 pm »

Quote from: Peter J on 12 Mar 2016, 04:01 pm

I've read this thread a couple of times and you know what? I really don't know how an electrostatic loudspeaker works!

I'm intrigued though, by both method and theory, so I'll follow along with interest. Who knows, maybe I'll pick up some knowledge along the way.

Thanks for posting Jazzman, your work is very cool. For me anyway, you couldn't post too much about it. Is there a place on DIY audio where the e-stat people hang out?

Try these videos:

How they are made: https://www.youtube.com/watch?v=V9Ln9HGasKg&feature=youtu.be

How they work: https://www.youtube.com/watch?v=Rok1s_aUDgY&feature=youtu.be

Jazzman53 · « **Reply #19 on:** 14 Mar 2016, 03:13 am »

Quote from: Peter J on 12 Mar 2016, 04:01 pm

I've read this thread a couple of times and you know what? I really don't know how an electrostatic loudspeaker works!

I'm intrigued though, by both method and theory, so I'll follow along with interest. Who knows, maybe I'll pick up some knowledge along the way.

Thanks for posting Jazzman, your work is very cool. For me anyway, you couldn't post too much about it. Is there a place on DIY audio where the e-stat people hang out?

Hi Peter,
My website is a good place to start: http://jazzman-esl-page.blogspot.com/
But the real ESL gurus hang out at the DIY Audio Forum planar section (link below). Golfnut, Bolserst, Cappaciti and Calvin are especially knowledgeable. Bolserst created the Segmented ESL Calculator (Excel spread sheet) I used to design my segmented ESL's.
http://www.diyaudio.com/forums/planars-exotics/