This GedLee NA12 visited the boutique!

poseidonsvoice · « **on:** 20 Jun 2018, 11:07 pm »

Most of you probably know at this point that I am a big fan of constant directivity and controlled directivity designs, particularly waveguide based ones. In addition, I follow the data driven research on acoustics and loudspeaker design of Toole, Olive, Geddes, etc...

A few years back I was lucky enough to acquire a pair of the now discontinued GedLee NA12's which sport an Earl Geddes designed 18 inch waveguide with neodymium drivers from B&C comprising a 1 inch compression tweeter and 12 inch woofer. In the Geddes design metric it is assumed that you implement multiple subwoofers as his speakers are limited to 50-60Hz in the low frequency. The NA12 supersedes and is the replacement for the GedLee Abbey in that it uses a larger waveguide, neodymium drivers and also a newer, much more resonant free enclosure. Most of the enclosure in this design uses a highly compressed and expensive ($300/sheet) foam product called Renshape along with improved bracing and constrained layer dampening techniques involving MDF with Renshape composites. The front baffle is about 2 inches thick; rear baffle is 1.5 inches thick, sides top and bottom are 1 inch thick, and the H-brace is 0.75 inches, 1.5 inches and 2 inches thick respectively.

Anyway, as lovely as they sound, I wasn't too enamored with the looks of the speaker.

And you know what they say about idle minds and diy’ers...

But before I get to that, I must wholeheartedly thank 3 individuals who were extremely gracious with their time and expertise.

Steve E. (sledwards here on AC) helped with the wood working in designing the rear panel and his advice in finalizing this rebuild was tremendous. He was the sole reason I was introduced to these fine gentleman below:

Mike Miles, the proprietor and wizard at Auto Arts in Raleigh, NC, a high end refinishing auto body shop whose clients own vehicles as prized as Porsche 959’s, Maserati’s, Lamborghini's and so on. Mike lives, breathes, and sleeps with a respirator because he IS the paint master!

Zach Matthews, a patron of the arts, the consummate ARTISTE whose airbrushing talents (amongst other things) have garnered him great praise from numerous clients who have a vested interest in stylizing their vehicles in the Raleigh area and beyond.

Here are some before pics:

What may not be obvious in the above photo is that the area encircling the woofer cone is a trim ring (made of Renshape) designed to hide the woofer holes and then veneered in 3M Di-Noc (a faux carbon fiber veneer). The finish is a satin gray.

The back panel similarly uses 3M Di-Noc.

And here are the after pics and details:

Back panel made with 3/4 inch MDF, cut, drilled, and primed:

The idea here was to design a binding post plate using Front Panel Express CAD software, and then epoxy that plate directly into the panel.

The original back panel had pretty wide tolerances to ensure a ‘comfortable fit.’ I really didn’t want that. As such, Steve and I worked on a design that really had no more than a 1/8 inch (3+ mm) tolerance all around for a more snug fit. In addition, new holes were drilled that were slightly smaller than the diameter of the wood screws and a nice hybrid wood/washer approach was utilized to tightly adhere the CLD back panel to the H-Brace (2 screws near the center of the rear panel above).

The binding post plate was designed on Front Panel Express and although the font looks like engraving, it is not! It is actually digital UV printing. I have always liked Cardas patented binding posts for their ease of use, and that is what you see here.

Pretty self explanatory with the main enclosures and some Isoacoustics stands in the paint booth!

Trim ring after painting and clear coat. This is not wood! Zach is so talented, he makes it look like wood, knots and all!

Here is where Zach shows some of his talents. I call it psychedelic yellow. It actually looks different at different angles.

Don’t worry, I did a trim ring in pure gloss black as well.

That’s what I am talking about! Poseidon’s Voice with the trident of Poseidon, flames and all! Woohoo!

Here is what the back panel looks like along with the center couplers that adhere to the H-brace inside the speaker enclosure. No Rez almost everywhere (none on the front baffle or close to the woofer cone). The crossover is in an external enclosure. Neotech silver gold wires and copper litz wiring, courtesy of Zenwave.

Don’t worry. The impedance/phase measurement didn’t change with the addition of the NoRez and wiring - I made sure!

The remaining pictures are pretty self explanatory:

That’s all folks! Tune in next time for the diy adventures of poseidonsvoice!

Best,
Anand.

Wind Chaser · « **Reply #1 on:** 20 Jun 2018, 11:27 pm »

Wow, I can't imagine how long that took or how much it cost - but those look exceptionally nice!

Tyson · « **Reply #2 on:** 20 Jun 2018, 11:27 pm »

Absolutely phenomenal!

poseidonsvoice · « **Reply #3 on:** 20 Jun 2018, 11:28 pm »

Quote from: Tyson on 20 Jun 2018, 11:27 pm

Absolutely phenomenal!

Quote from: Wind Chaser on 20 Jun 2018, 11:27 pm

Wow, I can't imagine how long that took or how much it cost - but those look exceptionally nice!

About 3 months and thanks!

Best,
Anand.

JLM · « **Reply #4 on:** 20 Jun 2018, 11:33 pm »

Congrats! An adventure of passion for sure.

Wind Chaser · « **Reply #5 on:** 20 Jun 2018, 11:35 pm »

Those are truly one of a kind; I cannot imagine you ever selling them.

I hope whoever eventually inherits them will appreciate them as much as you do.

Folsom · « **Reply #6 on:** 20 Jun 2018, 11:49 pm »

I love the rings.

Letitroll98 · « **Reply #7 on:** 21 Jun 2018, 12:10 am »

Excellent!

Phil A · « **Reply #8 on:** 21 Jun 2018, 01:26 am »

Great job!

gregfisk · « **Reply #9 on:** 21 Jun 2018, 09:25 am »

Anand, what a great project! You did an amazing job and really made these into pieces of art.

Love the paint job and the wood looking rings. Your artwork looks great as well, very custom indeed!

Take Care,

Greg

danvprod · « **Reply #10 on:** 21 Jun 2018, 09:56 am »

These came out amazing!

gab · « **Reply #11 on:** 21 Jun 2018, 02:38 pm »

Amazing work! Can you share pics of your external crossover box, how you wired it, how far away it mounts from the rear panel, etc?

gab

WC · « **Reply #12 on:** 21 Jun 2018, 02:43 pm »

Very Cool. Do they sound any different?

Nick B · « **Reply #13 on:** 21 Jun 2018, 02:50 pm »

Very, very nice, Anand.

poseidonsvoice · « **Reply #14 on:** 21 Jun 2018, 03:03 pm »

Quote from: gab on 21 Jun 2018, 02:38 pm

Amazing work! Can you share pics of your external crossover box, how you wired it, how far away it mounts from the rear panel, etc?

gab

The external box is actually behind a screen, a bit hard to access, but the cable connections are short, like 2 feet or less. When I did the repeat measurements, it was from the input of the external crossover box and they overlapped with the original crossover (phase and impedance). I didn't want to change anything electrically of course. This was done about 3 years ago - it's just bare MDF essentially. I need to finish it to this "new" standard that I have now!

Best,
Anand.

poseidonsvoice · « **Reply #15 on:** 21 Jun 2018, 03:06 pm »

Quote from: WC on 21 Jun 2018, 02:43 pm

Very Cool. Do they sound any different?

Don't know, but I strongly doubt it honestly since the actual dimensions of the enclosure didn't change, and neither did the impedance/phase measurements. They just look 'prettier.' The NoRez was there previously too, so basically, nothing much has changed acoustically or electrically. I might say that it 'sounds better' now but that is just a proud papa syndrome talking with the refinished cabinets!

Best,
Anand.

Nick77 · « **Reply #16 on:** 21 Jun 2018, 04:50 pm »

Hi Anand stunning work as usual, their gorgeous. I was under the impression you had gone active?? But based on your comments you using a passive crossover network, do you mind sharing what components your using? Duelund, mundorf??

Also what electronics are you using these days??

Thanks and nice work......

poseidonsvoice · « **Reply #17 on:** 21 Jun 2018, 04:57 pm »

Quote from: Nick77 on 21 Jun 2018, 04:50 pm

Hi Anand stunning work as usual, their gorgeous. I was under the impression you had gone active?? But based on your comments you using a passive crossover network, do you mind sharing what components your using? Duelund, mundorf??

Also what electronics are you using these days??

Thanks and nice work......

I have too many amp projects to count! I'm working on an F6 build as we speak. Of course, the excellent designs of Tom Christiansen (Neurochrome) are all here in my stable. I also have the famed 1200AS. That being said there are several pcb's downstairs that need to be populated...a quick perusal of diyaudio and you'll see all the usual suspects

I have the option of going active but I have not mustered the confidence and honestly my addiction to amplifier builds keeps me in the passive realm!

Regarding the passive components, you know the usual offenders: Jupiter Copper, Clarity MR, etc...nothing you fellas don't already know.

Best,
Anand.

WC · « **Reply #18 on:** 21 Jun 2018, 05:13 pm »

Quote from: poseidonsvoice on 21 Jun 2018, 04:57 pm

I have too many amp projects to count! I'm working on an F6 build as we speak. Of course, the excellent designs of Tom Christiansen (Neurochrome) are all here in my stable. I also have the famed 1200AS. That being said there are several pcb's downstairs that need to be populated...a quick perusal of diyaudio and you'll see all the usual suspects

I have the option of going active but I have not mustered the confidence and honestly my addiction to amplifier builds keeps me in the passive realm! You know the usual offenders: Jupiter Copper, Clarity MR, etc...nothing you fellas don't already know.

Best,
Anand.

Wouldn't too many amplifiers send you towards the active realm. It is for me.

poseidonsvoice · « **Reply #19 on:** 21 Jun 2018, 05:17 pm »

Quote from: WC on 21 Jun 2018, 05:13 pm

Wouldn't too many amplifiers send you towards the active realm. It is for me.

In all honesty, this is a hybrid system. Passive for the Geddes NA12 and active for the multiple subs that I have. I feel it is the best of both worlds while utilizing each design type/philosophy to the extreme. That being said, I have high regards for fully active systems like the JBL M2, Geddes NS15, etc...

Best,
Anand.