Another ESL speaker project

[Hayabusa]

Forgot to mention:
I've done A/B comparisons of the sound of segmented versus unsegmented panels using the very same panel operating in switch-selectable narrow and wide dispersion modes. This panel used welding rod conductors with a multi-pole rotary switch inserted to enable jump-over the segmentation resistors (for narrow mode) or leave them engaged (for wide mode).

The switch mode feature was fun but the novelty wore off fairly quickly because the switch was on the HV side so I had to power down to switch modes (to avoid frying the switch) and then re-EQ the panel because changing modes also changed the response curve.

Here's a link to that project: http://jazzman-esl-page.blogspot.com/2008/03/a-segmented-wire-stator-esl-with.html

Cool!

What was the conclusion on the A/B comparison?

 

[Jazzman53]

Cool!

What was the conclusion on the A/B comparison?

For anyone who's never stood at the focus of a pair of large, unsegmented flat panel ESLs; it's impossible to imagine how intensely directional they really are. Assuming the panel was tuned into balanced at the focus; the purity and imaging are downright magical. But it's got your head in a vise-- and if you move your head even a foot outside the focus; the highs fall off a cliff and some of the magical imaging is lost.

Most notable when the panel is switched to wide mode is the head-in-a-vice sensation disappears and the sweet spot expands to maybe 5 feet wide. Definitely more balanced and less finicky about positioning.

Whenever the mode is switched; the panel needs to be re-equalized because of the response has changed. An unsegmented flat panel, and even a curved panel to a lesser extent, has a rising frequency response resulting from beaming highs and the dipole roll off on the bottom end.

Whereas; a properly segmented flat panel spreads the highs and flattens the response curve down to the low end cut off. So; it requires relatively little EQ'ing to achieve balance. I also think a segmented flat panel is less fatiguing than a peaky, beamy unsegmented flat panel.

Both are wonderful in their own way. When I had the switch mode panels; I found myself listening mostly in wide mode, even when alone. That's why I didn't include a switch mode feature in my new speakers.

 

[Jazzman53]

Update 3/23/20:

All four pairs of speakers are fully completed except for the magnetically attached grills, which I started building today.

I spent the weekend sound testing every pair, and they all play to ridiculous volume with no apparent issues. For a $77 woofer; I'm pretty impressed with the Peerless SLS-- I was concerned it wouldn't be up to the task so I only ordered one pair initially. I should point out that so far I've only sound tested them chopped off at 60Hz and crossing into a pair of Ripol subs with a 24db filter slope. Thus unloaded on the bottom end; the Peerless woofers rock pretty well without bottoming out at X-max.

Parts Express had the black grill cloth but not the burgundy I want for my pair-- so I was happy to finally locate some 66" x 36" sections on Ebay. That order arrived today and it's only 54" x 36". With the Corona virus lurking and me old as dirt, I'd rather lose the refund than risk the post office to return a package.

Just one more delay in wrapping this project up...

In the meantime-- here's some more porn for all you planar pervs:

 

[Jazzman53]

Update 3/26/20:

Having a lot of problems with the grill frames. They looked great the day I built them but they bowed after a couple of days and I'm having to redo them. The first time I used white pine stiffeners on the hardboard frames, the second time I used poplar. Both bowed but the poplar bowed a bit less. So I'm cutting the stiffeners off and bonding new stiffeners on with the frames purposely bowed in the opposite direction, hoping they will bow back to near straight condition. I may end up giving them a week or so to stabilize, then cross cutting slots in the vertical stiffeners to relived the bow, and then gluing on some strips to re-stabilize. They will look nice if I can resolve the bowing issue:

 

[Jazzman53]

Hi all,

This project (all four speaker pairs) is finally completed, so this will be my last post on this thread unless it's in response to others.

I resolved the issue with the grill covers bowing and they turned out gorgeous.

I finally now have my dream speakers for life, and I'm sure the recipients of the other three pairs will feel the same way.

I'll just leave you with a last video of the speakers playing:

 

[SIY]

This was seriously excellent work and I'm highly envious.

 

[PaulD]

Bravo! Truly magnificent, and congratulations!

I too am highly envious, and I have large Quads with subs