[Jazzman53]

Update Monday afternoon, 3/14/16:

All woodwork completed-- temporarily dry-assembled the interlocking lattice pieces last night and today (no glue) and sprayed on the light colored stain and satin clear coat.

I've just started gluing up the first stator as I’m posting this. The first photo shows all four lattices after stain/paint. The second photo shows the first stator in the stretcher jig with the first 3 horizontal wire supports are glued in place over the wires.  When the glue sets on those, I’ll move on to the next three.

I won't know for sure until I complete the first stator but it looks like this scheme is gonna work.

I stretched the 48" wires .50 inches, then relaxed almost all tension. I had to use larger diameter pins in my jig than what would have given correct wire spacing so I'm using threaded rods to get the spacing right.

[Jazzman53]

More porn for you planar pervs:

Got the first stator completed, three more to go.

 

[SteveFord]

Hubba Hubba! 
You work quick.

[Hank]

NICE work progress!  Did you get kiln-dried oak at optimum moisture content to minimize warping, cupping and twisting?  The poly will prevent future moisture ingress/egress.

[Jazzman53]

Those planks were sawn out of a tree and air dried in a barn for 80 or so years before I got hold of them.  I bought a pickup truck load for 40 bucks.  Unfortunately, they were apparently stacked without stickers between them and worms long ago made lunch out of most of it.  What the worms didn't eat or rot didn't get dried hard as a rock though.  If you look close you might see some worm holes in the photos.

I don't have any CNC machines-- just a cheap 6" jointer, a 12" planar, home made router table and a 10" table saw. 

Rather than cutting out details one at a time I just cut and profiled some boards and then sliced out the details on the band saw.
The horizontal wire supports are only 3/16 thick so a 5 inch board yields a good bunch of those. 
 
After facing the boards flat on one side I ran them thru the planar many times, taking only a little off with each pass (1/32" at first, then 1/64") while eyeballing for warp.  When I perceived a warp developing, I cut the cut the convex face on the next pass and the board goes flat again. 

Once planed the boards were pretty flat and stayed flat thru the cutting the profiles (angles and interlocking dado cuts). 

       

[a.wayne]

Why wood , instead of the usual plastic grids used on  drop ceiling lights  ... ?

[Jazzman53]

Why wood , instead of the usual plastic grids used on  drop ceiling lights  ... ?

I opted for wood for purely esthetic reasons.  For the past 18 months I've used segmented plastic grid/welding rod panels in my beam splitter ESL's and they sound wonderful but they're just butt ugly.  Even with clear coated copper coated tig rods on a black grid, they're still not pretty. 

So I went from some really nice looking but very directional perf metal panels to the plastic grid panels and now I want segmented panels that are esthetically pleasing...  and I think these new wood lattice/ wire panels will be gorgeous mounted in the beam splitters.  I just hope they sound as good as they look. 

I'm a bit concerned about their weight/mass, though, as I've never built stators this light.  Even my old heavy perf metal panels vibrated when playing so it's a given these featherweight wood slat copper wire panels will vibrate considerably more.  Hopefully, their vibration will not be audibly  objectionable.   

The pics below show my old perf metal panels and my current plastic grid panels... as you can see, the wood panels will be very attractive in comparison.


 

[Jazzman53]

Update 3/24/16:

The stators are finished and the diaphragms were installed and conductive coatings applied this afternoon. The coatings need twenty four hours to dry and then I can assemble the panels. The resistors and bread boards for the RC networks were ordered today--- still gotta build the networks. I figure another week to wrap this up.


Photo 1: Bonding stator to the tensioned diaphragm, on my pneumatic (bike tube) tensioning jig. Diaphragms were tensioned to 1.4% elongation.


Photo 2:  Diaphragm installed

[gregfisk]

This has been really interesting to watch, not knowing anything about these types of builds. What are the diaphragms made of and how do you attach them to the frames?

Really nice work by the way!

greg

[Jazzman53]

Hi Greg,

The diaphragms are 6-micron thick Mylar and are attached to the stators with .063 thick urethane foam double sided tape.  The foam tape is both the adhesive and the spacer that sets the diaphragm to stator gap at .063", which is ideal for a hybrid panel operating above 200Hz.  The foam tape is a very popular DIY construction method which bonds the diaphragm to the stator instantly with no fuss, no mess. 

The diaphragms are also coated with Licron Crystal ESD spray on coating to make them slightly conductive.  There is a lot of info on operating theory and construction on my website here:  http://jazzman-esl-page.blogspot.com/

[SteveFord]

This is what, you're third of fourth speaker build?
What are you doing with them all once you finish latest pair - multiple stereo set ups?

[Jazzman53]

Not building whole new speakers, just replacement ESL panels.  I'm still using my same old beam splitter transmission line bass cabs and frame. 

These are are the seventh pair of ESL panels I've built.   Three were perf metal panels built for other people (I stopped doing that, BTW).   
In addition I still have the segmented welding rod panels and two pairs of steel perf panels lying around. 

Assuming that I will prefer these new wood panels over the welding rod panels, Martin from the CarverSite (who also lives in Savannah) has dibs on his choice of my other panels but he has no woodworking skills so I would probably end up having to do the cabs for him too.  And then I will have two sets of hybrid panels left... probably the perf panels.         

[a.wayne]

Jazz

That's  really Looking sweet now  , still way too much work  being lazy , I will stick to doing big  Ribbons ....

Do  you plan on measuring when done ...?

[Jazzman53]

Yeah, you're right about the work.   By comparison, perf metal panels are easy... I can build a pair of those in a single weekend.   

[Jazzman53]

Update 3/29/16:
Got the resistor networks built yesterday & one panel mounted in one speaker last night.  This evening (after work) I will connect the resistor network to the other panel and maybe even get the panel installed into the other speaker and hear some music. 

Below:  Resistor network wired up to the panel.  I have the network encased with a clear plastic cover over it—lest I get a thrill if I happen to sick my hand back there while the speaker is playing.


Below:  Very sexy sneak preview > poor photo taken in low light… will get better pics this afternoon. 

[bpape]

I really like that look.

[Jazzman53]

Me too... visually a big improvement over those butt ugly welding rod panels I've been using. 

[Hank]

Coming along great, Jazzman53!

[Jazzman53]

My speakers are finished and they are playing tonight as I'm writing this.  My expectations are met and exceeded... I don't even need to do any tweaking, they are fantastic right out of the box.  Seamless blending with the woofers, pristine highs, slam, imaging, all wonderful.

[Rocket_Ronny]

Wow. Respect.

Rocket Ronny