AudioCircle
Audio/Video Gear and Systems => Planar Circle => Topic started by: Jazzman53 on 2 Jul 2017, 05:26 pm
-
Hi all,
It looks like my latest DIY electrostats are to be featured in the September issue of AudioXpress magazine :thumb:
Here's a short cellphone vid of them playing at the 2016 Carverfest:
https://www.youtube.com/watch?v=eXL4NsMtpYk
-
Congratulations!!!!
-
I can actually hear the extraordinary transparency of your speakers via youtube. :o
Congratulations on the publication of your article. :thumb:
-
We're still waiting for you to go into production...
-
Wow, this is awesome news. Congratulations.
-
We're still waiting for you to go into production...
I would surely starve if I had to build speakers for a living.
-
How much time, and money's went into building them ?
I have owned most speakers out there MLB 111, still on my favorite list when I win the lottery.
I bought the New Martin Logan 11-A Loudspeaker.this being the least expensive in their Powered
subwoofers in the masterpiece series.usjng 24 bit DPS, and dual opposing powered subs per speaker
With Anthem room correction gives a totally seamless presentation. I bought these for I feel this series
Compete against anything at 2x the cost in balance across the board.
The stats in the link above look very nice. These were not available for sale when I purchased mine
But look very well constructed.. where are you located ? Will you be selling these starting out
A few at s time like Vapor Loudspeakers just more efficient would be very good . Please elaborate
A bit on your design, efficiency,and frequency response., powered ,and or passive subs ?
-
How much time, and money's went into building them ?
Please elaborate a bit on your design, efficiency,and frequency response., powered ,and or passive subs ?
Hi Audiophile58,
Material cost for the pair, digital crossover included but not the amps, is about $1,300. Time-wise I spent about 7 or 8 weeks of evenings and weekends. The beam splitter bass cabs were the lions share of the work. Believe it or not the most difficult item to design was the wire stretching jig. In comparison to the cabinets, building the stat panels and power supplies was the easy part and went much faster.
I have no plans to build speakers for sale though. If I did, I would have to re-design something easier/faster to build, as my current speaker would not be commercially viable (it takes a hand truck to move one-- shipping alone would be horrendous).
I do use Ripole subs and the system is tri-amplified. Absent the subs the speakers would play down to 22Hz and top out at 20Khz. Adding the subs unloaded the mid bass woofers a bit and let the system REALLY ROCK. The panels would play above 20kHz except the digital crossover chops off the output sharply at 20K.
I haven't measured the efficiency but the panels are optimized for high output (ideal wire size, wire spacing, minimal diaphragm to stator gaps) so should be quite good for an ESL --comparable to a hybrid model ML I suspect.
Complete build photos, parts list, schematics, etc.. are shown here: http://jazzman-esl-page.blogspot.com
-
Excellent news, Jazzman.
Your project is the type of thing that should be featured much more prominently in the Audio press.
Dave.
-
The September 2017 online edition of AudioXpress magazine, containing my speaker article, came out today. I was a little disappointed that my speaker wasn't on the cover (commercial speakers won out there) but they did a very nice 8-page layout of my speaker article inside.
Below are the cover and the first page of my article:
(http://www.audiocircle.com/image.php?id=166732) (http://www.audiocircle.com/image.php?id=166733)
-
Hi Jazzman53,
Is that issue available online for download or can you add a PDF link :?:
-
Hi Jazzman53,
Is that issue available online for download or can you add a PDF link :?:
It's available for download or print copy from the AudioXpress website but you'd have a buy a 1-year minimum subscription to get it. I don't have a subscription myself but they're sending me a courtesy print copy. The cover screenshot I pulled from their website. I do have a PDF of my author's proof but I can't post it because the article now legally belongs to AudioXpress. I can tell you though that practically every paragraph and all photos in the article were copied and pasted verbatim from my website (http://jazzman-esl-page.blogspot.com/). So, if you've read my website, then you've essentially read the article; although the article layout is much prettier.
-
Thanks, I've got your website bookmarked. Micro center down the road from me carries AudioExpress, I'll call and see if they have September. :thumb:
-
Very nice work. I cannot tell over youtube, but they appear very well constructed! Congratulations
-
Thank you all,
The new segmented wire panels are the culmination of a nine year journey through multiple design iterations and I believe they are the current state of the art.
And I can’t tell you how rewarding it is when I get an email from someone on the other side of the world who built their own ESLs using my website as a guide and they rave about how great they sound—because I KNOW what the effort and the result meant to them.
Charlie
-
Just superb. Wish there were a way to do it without that wire stretching jig, though!
Anyway, congratulations on the article.
-
Just superb. Wish there were a way to do it without that wire stretching jig, though!
Anyway, congratulations on the article.
Actually, stretching the wires is not an absolute requirement but it does produce straighter wires and tighter tolerances for the diaphragm to stator gaps.
-
What about the welding rod? Arcing problems?
-
I never had any arcing problems with the welding rod panels at the biasing and stator voltages I was using (2.7kV bias voltage and 76:1 step up transformers).
There were 3 mitigating factors: 1) the welding rods being round have no sharp edges to focus the corona, 2) the rods were over coated with 6-8 mils of clear coat polyurethane and 3) the diaphragm coating had quite high resistance (E7-E9) which restrained charge migration across the diaphragm (whereas a low resistance coating like graphite would permit rapid charge migration to areas of closest proximity to the stators at any given time).
-
Why did you go to the stretched wire, then? Wasn't the welding rod easier to use?
-
Why did you go to the stretched wire, then? Wasn't the welding rod easier to use?
The only advantage to using welding rods is that you don’t have to build a stretching jig, as they are perfectly straight right out of the box.
And now the downside:
If using use light diffuser grids to support the rods (as I did), it’s a pain to run a glue line across every rung of the grid and the glue line tends to stand a proud of the rods’ surface rather than laying perfectly flush, as desired. Also, welding rods are only 36” in long so if you want panels taller than 36” you would either have to butt/solder them (very difficult) or butt but not solder them, in which case you would then have to connect power leads at both ends. And you would have to over-coat them too if you want an extra measure of arc resistance.
I opted for wire/oak lattice stators because I wanted my panels to look as good as they sound and also match the nice oak woofer box & frame assembly. The wire panels are also more finely segmented to give even smoother dispersion (beats any curved panel, hands down). The biggest headache with wire panels is designing a proper stetching jig—and mine works perfectly. After agonizing for a considerable time over the jig design, building it was fairly easy.
The interlocking oak stator lattices were a bit time consuming but not all that hard to build—I just cut and profiled some boards on the table saw and router table and then sliced out the individual pieces (from the profiled boards) on the table saw. Some woodworking experience is required but you don't need to be an expert (I’m not).
I would be happy to provide dimensioned CAD drawings for my stretching jig and stator lattices to anyone who wants them.
I can tell you that I would not build welding rod / light diffuser stators again. In fact I still have the ones shown on my website which I would sell for less than it cost me to build them -- but then the buyer would lose out on the biggest reward of all, which is the DIY experience.
-
Yeah, the jig is the scary part, but the dimensioned CAD drawings would be a real help.
Agree that segmentation is the way to go -- I've been waiting for someone to make a commercial segmented line source stat, but unfortunately, the market for large panels isn't very good right now . . .
-
Yeah, it's a shame that no commercial source that I know of makes a segmented line source ESL. Technically, ER Audio in Australia has a kit speaker that qualifies but it has only 2 segments-- a wider bass-mid panel and a separate narrow tweeter panel, which would not provide the same smooth trending dispersion of a multi-segmented wire panel.
I think you can build a better ESL than you can buy right now.
-
Hi, the ER Audio Acorn is three segments - http://www.eraudio.com.au/DIY_Speaker_Kits/Acorn_ESL_kit/acorn_esl_kit.html
-
I stand corrected :oops:
-
Yeah, it's a shame that no commercial source that I know of makes a segmented line source ESL. Technically, ER Audio in Australia has a kit speaker that qualifies but it has only 2 segments-- a wider bass-mid panel and a separate narrow tweeter panel, which would not provide the same smooth trending dispersion of a multi-segmented wire panel.
I think you can build a better ESL than you can buy right now.
I suspect you're right.
There have actually been a number of segmented ESL's but they typically still beam and can have less than uniform dispersion with frequency.
Also, there's a difference between the crossover/segmentation approach and the time delay approach pioneered in the ESL-63. The time delay approach is better. It produces a better polar pattern, avoids the lobing issues in a crossover, and also allows you to achieve higher output with lower distortion because all frequencies play across the entire panel (although you might get more IM).
-
My panels are finely segmented symmetrically about the centerline using 15 discrete wire groups. The RC line functions as a series of low-pass filters between the wire groups which creates a wider and smoother trending dispersion pattern than a curved panel of similar dimensions. The RC filters attenuate frequencies predominantly but also impart a slight delay (to the extent that the charging time for the inter-wire capacitance component is greater than zero). I haven't calculated the delay component but, in any case, the net effect of the segmentation scheme is remarkably apparent by merely walking around the speaker while it's playing and it's also evident in directivity sonograms comparing unsegmented panels, curved panels, and multi-segmented panels like mine:
http://www.diyaudio.com/forums/planars-and-exotics/246846-time-esl-builder-14.html#post4163636 (http://www.diyaudio.com/forums/planars-and-exotics/246846-time-esl-builder-14.html#post4163636)
-
Very impressive build, you are very much correct to be proud of the build.
I was wondering if you could give some more information about the amplifiers you are using (power output, impedance rating), and if there are any special considerations when choosing amplifiers.
-
I was wondering if you could give some more information about the amplifiers you are using (power output, impedance rating), and if there are any special considerations when choosing amplifiers.
The system includes the hybrid ESLs and a pair of Ripol subs in a trip-amp arrangement consisting of a Behringer DCX2496 crossover feeding three vintage Carver TFM-25 amps, each amp rated at 225W/channel into 8 Ohms. The crossover frequencies are 50Hz & 228Hz using the Behringer's 48db/octave Linkwitz-Riley filter slopes.
Whereas conventional stat panels are predominantly a capacitive load, my multi-segment RC wire panels are predominantly a resistive load. With the resistors in circuit, the capacitance reflected back to the amps is roughly equivalent that of first 2 wire groups in the series. So, practically any quality amplifier could drive my panels, whereas less stable amps could get smoked driving conventional stat panels. Even so, I would recommend at least 100 w/channel.
The Carvers had no problems driving my old perf metal panels either, BTW.
-
I was wondering about using direct servo subs in the ripole. What's your opinion?
~S
-
I was wondering about using direct servo subs in the ripole. What's your opinion?
~S
I have no experience with Servo subs so I will not offer an opinion on this.