[Jazzman53]

Hello everyone,
I just found the Audio Circle and joined yesterday.  This looks like the place to post DIY projects and I have one to share.  Here's a link to my DIY electrostatic speaker project:

http://jazzman-esl-page.blogspot.com/

I'm loving all the cool projects in this circle!
Charlie
(Jazzman53)

[jtwrace]

Jazzman-

Welocome to A.C.!!!

I've been waiting for a DIY electrostic guy to come along.  You're not to far away from me either...I'm liking this already.   

With your skills on 'stats and mine with metal, we could have an awesome project.   

I can't wait to go through your site.

[BobC]

Those look fantastic!  I really like the beam splitter concept.

Questions:
1. How do they perform compared to Martin Logans?  Maybe the Summit X at $14k?
2. Which leads to the question of what was you total cost and time spent?

I own ML Ascents and love them, and I tinker with woodworking, but I never considered a DIY electrostat.  Hats off to ya!   

[coke]

Impressive! 

[ebag4]

Very cool project Charlie!

Welcome to AC.

Best,
Ed

[bpape]

Nice project.  I love 'stats. 

Do you find that the 10" in the TL is quick enough to keep up with the panels?  Where are you crossing them over or did I miss that in your blog?

Bryan

[Wind Chaser]

They look very nice.  About how sensitive?  Thirty years ago I owned a pair of the Acoustat Model 2, so I know what you mean about beaming and 'hearing it all' even at the lowest volumes.  I had mine pulled out 5' off the from the front wall.  Stats are great within their limitations but, I find they don't do so well with extreme dynamic range.  Try the Sheffield Drum Record and you'll quickly see what I mean. 

[bpape]

I have the Acoustat MONITOR 4's (not to be confused with the flat Model 4's).  No transformers.  They use direct drive tube amps instead to generate the high voltages required.  Their dynamics and bottom end are what sets these apart from some other 'stats.  The pseudo-curved array also allows a wider sweet spot, though there is still definitely that one place where everything just clicks.

Boy.  This sure would be a great thread for a Panel Circle 

Bryan

[Wind Chaser]

Boy.  This sure would be a great thread for a Panel Circle 

It sure would.  I just passed up a great deal on a used pair of 1+1s.

[cujobob]

This is too cool, I didn't know it was possible to DIY electrostats... always wanted a pair of 'stats, I figure, use them with some servo subs?

[jtwrace]

This is too cool, I didn't know it was possible to DIY electrostats... always wanted a pair of 'stats, I figure, use them with some servo subs?

Oh sure.  If it's been made before it can definetely be done..if it has not, it requires a few things.  Vision, Money & Time (in that order). 

Yes, servo would be ideal IMO.

[ebag4]

This is too cool, I didn't know it was possible to DIY electrostats... always wanted a pair of 'stats, I figure, use them with some servo subs?

The OB servo subs would be a perfect match IMHO.

Best,
Ed

[Jazzman53]

Those look fantastic!  I really like the beam splitter concept.

Questions:
1. How do they perform compared to Martin Logans?  Maybe the Summit X at $14k?
2. Which leads to the question of what was you total cost and time spent?

I own ML Ascents and love them, and I tinker with woodworking, but I never considered a DIY electrostat.  Hats off to ya!   

Hi BobC,
Thanks for the nice comments.  I will attempt to answer your questions:
1. Your first question I can't answer, since I haven't had the pleasure of hearing the ML Summits (let alone side by side in the same room for comparison).  I did hear a pair of ML hybrids at a stereo dealer in Chattanoog back in 2006 but I can't recall the model and I wasn’t able to really crank them up to see what they could do.  I really feel out on a limb trying to make a blind comparison based on that memory alone but here goes:  I would say those other model ML's I heard had somewhat better tonal balance, a much wider sweetspot and they were gorgeous too; whereas, mine have somewhat better imaging (but only inside their narrower sweet spot) and my TL bass has the nicer tone.  Mine are definitely more physically imposing (sort of like those big black oblisks on the moon in 2001 Space Odyssy) but that could pose a problem for spousal approval (I’m single).     

2.  You could build a pair like mine for around $750 in materials (excluding the active crossover and dual power amps).  You could go even cheaper ($500) by omitting the nice brass spiked feet, grills, opting for a simpler bass box, cheaper stator coating, cheaper woofers and a cheapo DIY graphite or hand-soap diaphragm coating. 

If I counted my labor as cost I might have come out ahead just buying a pair of those Summits!  My bass boxes were exceedingly time consuming to both design and build-- for that reason, I encourage others to go with a simpler frame and cabinet unless they’re competent woodworkers who know what they’re getting themselves into-- it always takes longer than you imagine.  I spent 5 months of my project.... much of that time was in research and drafting the design but quite a lot of actual labor went into the cabinets, especially. Once you have all the materials on hand, the stat panels themselves are fairly easy to build (a long weekend will do it).       

The real price drivers are the transformers, woofers and stators.  Reasonably priced transformers are very hard to find in the US.  I’ve found and listed on my blogpage some very good sources and prices for the materials.  For example:  A pair of specialized Aplimo or Plitron ESL transformers alone go for $600+ but thanks to DIY geniuses like my friend Calvin at the DIY Audio Forum, we can confidently substitute a quad of 50VA 230v/2x6v standard power toroids for under $100 and get almost equivalent performance.  I’m all about saving money, since I don’t have much of it (got an ex-wife to support).         

[Jazzman53]

Those look fantastic!  I really like the beam splitter concept.

Questions:
1. How do they perform compared to Martin Logans?  Maybe the Summit X at $14k?
2. Which leads to the question of what was you total cost and time spent?

I own ML Ascents and love them, and I tinker with woodworking, but I never considered a DIY electrostat.  Hats off to ya!   

Hi BobC,
Thanks for the nice comments.  I will attempt to answer your questions:
1. Your first question I can't answer, since I haven't had the pleasure of hearing the ML Summits (let alone side by side in the same room for comparison).  I did hear a pair of ML hybrids at a stereo dealer in Chattanoog back in 2006 but I can't recall the model and I wasn’t able to really crank them up to see what they could do.  I really feel out on a limb trying to make a blind comparison based on that memory alone but here goes:  I would say those other model ML's I heard had somewhat better tonal balance, a much wider sweetspot and they were gorgeous too; whereas, mine have somewhat better imaging (but only inside their narrower sweet spot) and my TL bass has the nicer tone.  Mine are definitely more physically imposing (sort of like those big black oblisks on the moon in 2001 Space Odyssy) but that could pose a problem for spousal approval (I’m single).     

2.  You could build a pair like mine for around $750 in materials (excluding the active crossover and dual power amps).  You could go even cheaper ($500) by omitting the nice brass spiked feet, grills, opting for a simpler bass box, cheaper stator coating, cheaper woofers and a cheapo DIY graphite or hand-soap diaphragm coating. 

If I counted my labor as cost I might have come out ahead just buying a pair of those Summits!  My bass boxes were exceedingly time consuming to both design and build-- for that reason, I encourage others to go with a simpler frame and cabinet unless they’re competent woodworkers who know what they’re getting themselves into-- it always takes longer than you imagine.  I spent 5 months of my project.... much of that time was in research and drafting the design but quite a lot of actual labor went into the cabinets, especially. Once you have all the materials on hand, the stat panels themselves are fairly easy to build (a long weekend will do it).       

The real price drivers are the transformers, woofers and stators.  Reasonably priced transformers are very hard to find in the US.  I’ve found and listed on my blogpage some very good sources and prices for the materials.  For example:  A pair of specialized Aplimo or Plitron ESL transformers alone go for $600+ but thanks to DIY geniuses like my friend Calvin at the DIY Audio Forum, we can confidently substitute a quad of 50VA 230v/2x6v standard power toroids for under $100 and get almost equivalent performance.  I’m all about saving money, since I don’t have much of it (got an ex-wife to support).         

[bpape]

I'm sure the TL bass is far superior to the ML. 

Congrats again on a very unique design.

Bryan

[jtwrace]

I owned a pair of ML Summits for 6 months then sold them.  I was very disappointed. 

I've owned ML CLS, CLS IIz, Quest, QuestZ.  So I'm very familiar with the ML sound. 

[Jazzman53]

They look very nice.  About how sensitive?  Thirty years ago I owned a pair of the Acoustat Model 2, so I know what you mean about beaming and 'hearing it all' even at the lowest volumes.  I had mine pulled out 5' off the from the front wall.  Stats are great within their limitations but, I find they don't do so well with extreme dynamic range.  Try the Sheffield Drum Record and you'll quickly see what I mean.

Hi Wind Chaser,

Unfortunately I don't have equipment to measure my speakers' sensitivity but but I did plan the design for good sensitivity.  I've not heard the Acousat 2's that you mentioned but I believe they are non-segmented (having a single large diaphragm) and were full range (?)

There are tradeoffs with any design. Full range operation gives superior coherence and transient speed that extends all the way down to the speaker’s lowest frequency output, as there is no crossover to muddy things up and no transitioning to a [slower] woofer going on.  On the flip side, a full range's diaphragm-to-stator spacing (d/s) has to be wide enough to accommodate the greater diaphragm excursion needed for bass output (typically 0.12” to 0.25”), which limits sensitivity substantially and max dynamic output somewhat.  Additionally, I believe the Acoustats used wire-stators with fairly large diameter wires and relatively large spacing between the wires (as compared to perf-metal stators)-- great for open/airy sound but not for sensitivity.  From the comments I’ve read about the Acoustats on the DIY Audio Forum, I can imagine they would sound fabulous but need huge power and can’t play all that loud.

An ESL's diaphram/stator spacing (ds), transformer step-up ratio and biasing voltage collectively determine the sensitivity--- of these parameters, the d/s dominates because the charge strength falls off quadratically-- thus, if the d/s is doubled, the input power must increase by 4 times to produce the same acoustic output.

A hybrid ESL trades off some coherence and speed on the lower end for greater dynamics, higher sensitivity and typically lower/stronger bass.  My stat panels’ d/s spacing is only .062”, which is sufficient for a hybrid because the woofer handles the bass below 300hz so the diaphragms don’t need as much open space to move in.  The reduced d/s spacing is key to dynamics and sensitivity.  I’m a jazz guy so I don’t need to play all that loud but my speakers can easily exceed my pain threshold without distortion. 

As I tell my friends: “they won’t blow the windows out but they will blow women’s panties right off”   (this I have confirmed but my gf says that could happen anyway)

regards,
Charlie

[Phil A]

Charlie - great looking speakers!!!

[Jazzman53]

Jazzman-

Welocome to A.C.!!!

I've been waiting for a DIY electrostic guy to come along.  You're not to far away from me either...I'm liking this already.   

With your skills on 'stats and mine with metal, we could have an awesome project.   

I can't wait to go through your site.

If you ever visit Savannah, drop by my place and bring your favorite cd's. 

[jtwrace]

If you ever visit Savannah, drop by my place and bring your favorite cd's.

Matter of fact, I was speaking with my wife to go down there.  I absolutely love it and she's never been.  I've only been down there for the race track and was lucky enough to wander for a few days.  The best Pecan pie I've EVER had was on the coast.  Very well known place I think.

Consider it done!  We just need to set a date.