ER Audio Electrostatics

[Interious]

Does anybody have any experience with
these products? Rob Mackinlay tells me
that there are only a handful of his
products in the US, so I realize the
chances are poor.

I had an ESL phase some years ago
during which I built a dozen panels with
moderate success. I think I'd like to try
again and Rob's designs look appealing;
though the shipping from Oz is killer.
Dave

[ThomasW]

My mains consist of a pair of Acoustat 1+1 with a B&G RD75 and a line array of 16 leaf tweeters in between each pair of ESL panels.

Since they're are irreplaceable I keep my eye peeled for potential replacements for 4 Acoustat panels.

This is one US supplier I've considered using

http://www.justrealmusic.com/content/home1.htm

[Interious]

Say what??

What driver is doing what in your system Tom?
Acoustats on bass and BG for mids? Do you
have a picture?

Thanks for the link--excellent.
Dave

[ThomasW]

I don't have a final pic of the current configuration, but here's a pic before I added in the RD-75's



Here's a pic when we were testing the XO points, with the RD-75 held in place with shipping tape



Currently the RD-75's are attached to aluminum angle and suspended off the floor centered between the floor and ceiling. I haven't had the $$$ or opportunity to have my stone supplier fabricate a new base for the wider array

XO points of the current config are IB sub up to 80Hz, Acoustat panels 80Hz-600Hz, RD-75 600Hz- 6kHz, leaf tweeters 6kHz and up. The system is quad amped.

[Interious]

You must have concluded that the
Acoustat is wanting in the 600 - 6000 hz range.
Interesting.

What are you using for a crossover?

[ThomasW]

I use high modified Marchand XM9 active XO's.

Any ESL I've ever heard was soft in the highest frequencies.

The RD-75 is one of the most accurate 'midranges' I've heard.

The idea is to use only the 'sweet spot' of each of the radiating elements.

I've compared my system to the $125,000 Dali Mega-lines and a friends Pass Labs tri-amped Apogee Fullranges, to my ears neither sound as good. Some day I hope to hear the SoundLab U-1/A-1, it's the only 'uber' planar I haven't auditioned.

[Hank]

Thomas, thanks for the link. Interesting 'stats. Hmmm...if those really perform, I could avoid the complexity/expense of stacks of 8" drivers, a pair of B-G's that the Saint Saens are probably going to turn out to be. I'd like to listen to some of those 'stats.

[Interious]

What are the leaf tweeters?

I note that Justrealmusic uses .0005" film, and stator of the type and thickness used in Martin Logan designs. ER Audio uses 3.6 micron (.0001417") film and stator material thin enough to require external support.

Now--I have no idea whether if follows that ER's are superior. Just an interesting note since ER claims part of the secret to the performance of their designs is due to diaphram/stator thinness. It may be bunk.

I think Acoustat has used ~.0006" film, and Soundlab-- .00025", if memory serves. I don't know, the quality of the interface may swamp these considerations.

Anyway, JustRealMusic's prices are right. It is tempting to get a set of their panels and transformers to play with. Home fabrication of truly good stators is a big job.

Extensive fiddling with my DCX Arvos has compelled me to return to drivers thatare inherently suited for dipole use.
Dave

(Why is the justification of my paragraphs always a mess?)

[Interious]

Saint Saens general configuration:

Cones,
B-G,
Leafs?

Jon's mentioned it but darned if I can find it.

[ThomasW]

(Why is the justification of my paragraphs always a mess?)

Because you're inserting a hard return when you type (as if you're using an electric typewriter).

Saint Saens general configuration:
Cones,
B-G,
Leafs?

Yes

What are the leaf tweeters?

They're a tweeter consisting of a mylar element with a vapor deposited copper circuit on it. (sort of like a mini-Maggie), Each of mine have a 1 lb magnet in them.

[JonMarsh]

There's no thread dedicated to that project, yet. At the rate I'm traveling, who knows when there will be!

Technically, the planned configuration is:

Big Cones (not to be confused with cojones).
Little cones
B-G RD ribbon
Ribbon tweeters (true ribbon, not leaf)

I'm pondering another spin off of that, tentatively titled "Debussy", with just

Moderate size cones
B-G RD ribbon


(this one is to tease Hank...). That one would use some waveguide loading of the BG ribbon, and probably run the so called 10" Dayton RS sub drivers on the bottom end (dipole line array), as they're closer to 11", and they may go up high enough to mate with the RD around 400-450, hence using a waveguide to extend the lower end range and lower the distortion of the BG ribbbon.

Who knows... it's just a concept study right now. May be worthwhile if it can get 80-85% of the performance of the Saint Saen for a lot less money.

Jeez, was Chicago ever a mess this week... first time I've ever actually had to endure 8 hour plus flight delays...

~Jon

[cjd]

Jeez, was Chicago ever a mess this week... first time I've ever actually had to endure 8 hour plus flight delays...

You got that right! Ever stuck here longer, give me a ring eh? :P I can impress you with my ignorance. :lol: Or at least take you out for some nosh.

You have more data on those RS subs? Or just the same old data?

C

[JonMarsh]

I'll keep that in mind- the flight out to Detroit on Monday didn't leave until Midnight, when I was originally scheduled for 3:40 PM. The biggest hassle is the lack of online support at O'Hare- makes it hard to look up stuff or communicate with email!

Nothing newer than the 2nd prototypes, which in order to see, I had to sign away my first born should I forfeit and reveal anything to the "genearl public". Hmmm, where is that "Genearl Public" guy- is he in the Army?

Speaking of that, I'm thinking that the RS subs shouldn't be too far off by this time- but West coast boat shipping and freight is very congested this summer. May be a factor. Only Darren knows for sure.

~Jon

[Doug Lockwood]

and probably run the so called 10" Dayton RS sub drivers on the bottom end (dipole line array), as they're closer to 11", and they may go up high enough to mate with the RD around 400-450,

I am surprised that a driver with the xmax to call it a Subwoofer would be worth anything above 200 Hz or so. Even the RS270 isn't recommended above 500 Hz or so, and it’s a "classic" woofer.

Unless you know something we don't.

Doug

[JonMarsh]

The RS270 is OK up to about 600 Hz, then energy storage issues strike above that.

The Rs10's I've seen have well designed stiff aluminum cones, and a heck of a lot of copper in the VC gap- the 2nd ones even more than the first gen protos.

For comparison, the TC2+ is pretty good native up to 250 Hz. The RS10 sub has a stiffer, smaller, lighter cone.

'Nuff said for now... until I see production parts, anymore would be speculation. Of course, a little speculation here and there does liven up the heart and the boards.

~Jon

[cjd]

You can always point to the many Adire Audio offerings, like the Extremis, if you wish to provide an example of a high XMax driver with a broad frequency response.

Since we're on the topic of dipole, how low are the RS270's good in dipole use? I know not quite low enough, but really don't know what that "not low enough" translates to.

C

[JonMarsh]

Xmax limitations- 7 mm. they'll go low, but not very loud. You can see the trade-off using Linkwitz's spread sheet. About 4 dB less than a Peerless XLS 10 at 30-40 Hz (which is ~12 mm). My own experience suggests that the reasonable point for dual woofers in a dipole is around two 12's per side with 18mm+ Xmax. If one goes with RS270's, than about 6 per side, perhaps, would be close enough to start. When you think about it, that could be viable, other than the cost. Would have a nice upper bass and midrange, I think. I'm thinking that 4 per side of the RS 10" when their out might do the job nicely. Just speculation, of course.

~Jon

[Interious]

RS10 ???

Have you seen something we haven't seen Jon!?

Dave

[JonMarsh]

Uh, yes. Seen tested, too.

Somewhere over the rainbow...

[Interious]

You always see the cool stuff first.

It's not fair!

Dave

[Hank]

I'm pondering another spin off of that, tentatively titled "Debussy", with just

Moderate size cones
B-G RD ribbon


(this one is to tease Hank...). That one would use some waveguide loading of the BG ribbon, and probably run the so called 10" Dayton RS sub drivers on the bottom end (dipole line array), as they're closer to 11", and they may go up high enough to mate with the RD around 400-450, hence using a waveguide to extend the lower end range and lower the distortion of the BG ribbbon.

GRRRRRR...:banghead:

[Interious]

I selling all my Arvo stuff to build the Debussy.
Dave

[Paul Ebert]

Debussy

Jon,

As one wishing to build the Saint-Saens, but thinking I may have to settle on the Arvos (such a shame ), I'm interested in the 'Debussy'. Though I gotta say :P , it's hard for me to think of Debussy as a lesser composer to Saint-Saens. How 'bout 'Chabrier' or 'Bizet'?

Anyway... I'm curious what you are thinking about running the RD-75 into the high frequencies. Would you apply some eq to boost it?

Might you consider a small array of the Neo3s as a cheaper alternative to the Saint-Saens Fountek array?

It would certainly be very cool if you could design a scaled down Saint-Saens. If it could be upgraded to a Saint-Saens when funds permitted, that would be most excellent!

Oh, and any news on the Peerless exclusives?

Thanks.

Paul

[ThomasW]

The short answer is if you like the sound of the RD-75 with EQ go for it, a number of people are doing that. However the tall RD series tend to 'beam' at higher frequencies that's one reason we use ribbon tweeters.

We haven't played with the Neo 3. We prefer ribbon tweeters to planar tweeters. We tested the Neo 8 and weren't impressed.

The Saint-Saens is to be a 'statement' (no compromises) loudspeaker. So there won't be a scaled down version of the Saint-Saens unless someone else designs it.

BTW, the Saint-Seans was only 'named' recently, but we've discussed the concept ad-nauseum in at least 1/2 dozen threads over a period of 3 yrs. Here are the links

http://www.htguide.com/forum/search.php4?searchid=140427

[JonMarsh]

I have my first four of the 830884 Peerless Nomex Exclusives, but as I'm working all weekend, (Grrrrr), I won't be doing any testing. I may get a chance to do some before I head to Colorado week after next. One application I'm considering these for, besides the Arvo, is the "smaller" cone in the Saint Saens. It's got a nice open basket, flat sided frames which might stack up nice, and it would certainly work well in the 100Hz to 600 Hz region I'd need. The question is how does the midband distortio stack up against the Extremis, for example?

My gut feel says more Sd and less Xmax may be the better solution.

The RD run by itself is a bit of a compromise - but enhancing the lower end through waveguide loading would make it harder to add a ribbon line array, as the tweeter to mid distance would be too great. I don't see the Debussy as an "extensible" project, short of getting the better Radia drivers, or just pulling the drivers out and sticking them into the Saint Saens configuration.

This is really annoying to have this project delayed so long... all the wood, inlcuding the Pau Ferro, is sitting in the garage.

Tuesday we'll be interviewing a guy from Munich who might be an AE addition on the east coast that would ease my work load, but his skill set and experience doesn't look well matched to the task at all. Bright guy, though. Then, too, there's no personnel req approved yet, probaly won't be until sometime in October earliest.

~Jon