New ESL Project

Jazzman53 · « **on:** 14 Apr 2018, 05:25 pm »

This speaker project is for a friend who likes OB's. And the speakers must fit into his Audi for transporting (rear seats folded forward, speakers occupying trunk & rear passenger compartment). Thus; some compromises are required.

We settled on a modified H-baffle design with an electrically segmented wire-stator ESL panel, 66"H x 14.5"W x 15" base. The triangular base forms the H-baffle and is removable.

The drawing below shows the speaker with a Peerless SLS 12 woofer, front-mounted on the baffle, which was the initial plan. However, we have changed to a different woofer and mounting it on the rear of the baffle.

This will not be a stand-alone speaker-- a single 12 woofer on a baffle this narrow will not give thundering low bass. With that in mind, we opted to break the rules for OB and go with a low-Q woofer for optimal blending to the stat panel (Eminence Kappalite 3012LF). The woofer will only provide mid bass here. The lows will be handled by separate OB subs (each with two 15" AE's).

The panel is tried and true. The rest we won't know until we hear it play.

Jazzman53 · « **Reply #1 on:** 15 Apr 2018, 11:30 pm »

I'm at that stage of the project (this happens with every project) where I'm burned out and wishing I had never started it. My air compressor motor burning up today didn't help-- so now we're at an impasse for sanding and painting the frames. At least I finally finished cutting the stator details today-- two hard days on that. Can't finish without the air compressor to spray the stain and satin clear coat.

Below is my friend Martin hand sanding and pre-fitting the oak lattice stator supports. I think Martin is starting to grasp how no sane person would go thru all this to build a speaker... definitely a psychosis

Jazzman53 · « **Reply #2 on:** 17 Apr 2018, 09:01 am »

Update: Got the air compressor back up and running yesterday and sprayed stain on the stator lattices last night. After work today will spray the lattices with satin poly clear coat and tomorrow we can start stringing wires in the stretching jig. The stator lattices are 96 interlocking oak details... each piece hand sanded and fitted.

johnto · « **Reply #3 on:** 17 Apr 2018, 12:48 pm »

Looks sweet. Keep the updates coming.

66mgb · « **Reply #4 on:** 17 Apr 2018, 02:12 pm »

You have a LOT of patience ! Nice work. Would be curious on the total hours spent when finished.

JakeJ · « **Reply #5 on:** 17 Apr 2018, 03:35 pm »

Nice work, Charlie! Thanks for posting the build.

Jazzman53 · « **Reply #6 on:** 18 Apr 2018, 11:51 pm »

Stretching the wires and assembling the first stator tonight. Stretching the wires to 1.5% elongation renders them perfectly straight

Jazzman53 · « **Reply #7 on:** 20 Apr 2018, 09:10 am »

Update 4/20:
As of last night, one stator is finished and another is in the stretching jig awaiting the glue to set. Probably won't be able to work on it much this weekend (honey-do list -- overruled by higher authority) but will be back at it Sunday evening or Monday.

Rocket_Ronny · « **Reply #8 on:** 20 Apr 2018, 02:01 pm »

I am very impressed. Wow.

Rocket Ronny

johnto · « **Reply #9 on:** 20 Apr 2018, 02:59 pm »

Very nice. Can't wait for the sound report.

josh358 · « **Reply #10 on:** 21 Apr 2018, 08:21 pm »

Beautiful.

SteveFord · « **Reply #11 on:** 22 Apr 2018, 12:14 am »

Your friend really doesn't need to drive them all the way to Pennsylvania in his Audi for me.
FedEx is fine.
P.S.
These are coming along nicely, impressive work as always.

Jazzman53 · « **Reply #12 on:** 22 Apr 2018, 12:40 pm »

Quote from: SteveFord on 22 Apr 2018, 12:14 am

Your friend really doesn't need to drive them all the way to Pennsylvania in his Audi for me.
FedEx is fine.
P.S.
These are coming along nicely, impressive work as always.

OK Steve, I just verified the 66" tall speakers will fit into Martin's Audi. So if they don't meet Martin's expectations, we'll be needing your address.

SteveFord · « **Reply #13 on:** 23 Apr 2018, 12:03 am »

I should be so lucky.
Like everyone else I really enjoy your build threads.

Jazzman53 · « **Reply #14 on:** 30 Apr 2018, 02:23 am »

The project is on hold at the moment, until Martin decides about speaker feet, some of the electronics components, and ordering the Licron Crystal to coat the diaphragms.

In the meantime, I heat bent some polycarbonate covers for the electronics (step up transformers, high-voltage biasing supply, speaker cable binding posts, etc...) to be located on the rear shelf, as shown in the photo below:

Jazzman53 · « **Reply #15 on:** 12 Jun 2018, 02:17 pm »

Update 6/12/2018:

I finished my H-baffle hybrid ESL project late yesterday evening. It was a LOT more WORK than I imagined but it turned out really nice. I like having the segmentation resistor networks and transformers & bias supplies under clear plastic covers.

I did play them a little last night-- initially there was significant booming centered around 160Hz (probably the H-baffle’s cavity resonance) but they were sounding pretty good after tamping down the resonance with a parametric EQ. I will get them tuned in over the coming week and post a video later.

I didn’t start out building these speakers for myself but it ended up that way (for reasons I won’t go into here). And since I don’t have enough equipment to run both my old beam-splitter speakers and the new H-baffles, I suppose I will have to listen to them a while and then choose which ones to keep—it will be a difficult decision (rather like selecting one of your children to sell).
BTW; breaking the rules by using a low-Q Pro woofer in an OB might not be such a bad idea--- it was immediately apparent that these Kappa-Lite LF woofers have serious PUNCH and they seem to blend well with the stat panels.

Here’s some eye candy for the planar pervs:

JerryM · « **Reply #16 on:** 13 Jun 2018, 12:54 am »

Quote from: Jazzman53 on 12 Jun 2018, 02:17 pm

Update 6/12/2018: …

Those are absolutely gorgeous, Jazzman.

Very, very nice.

SteveFord · « **Reply #17 on:** 13 Jun 2018, 09:26 am »

If they sound half as good as they look you've got it made.

jsm71 · « **Reply #18 on:** 13 Jun 2018, 07:39 pm »

These are indeed very nice looking. At what frequency do you cut over the woofer? Sorry if I missed this detail from earlier.

FullRangeMan · « **Reply #19 on:** 13 Jun 2018, 08:05 pm »

Fantastique handy work Jazzman congratulations

There is any way you can adjust the planar decay resonance time?