ESL: Mylar 4 micron vs Polyester 3.8 micron

[michaelpage26]

Mylar 4 micron or Polyester 3.8 micron?
which is better membrane material?

Here are some opinions

Roger Sanders (Innersound):

"Please be aware that there is ”Polyester” and there is ”Mylar.” Cheap imported polyester film will not heat-shrink well, nor will it maintain tension over long periods like genuine Dupont ”Mylar.” Also, polyester is normally annealed so that it will not heat-shrink very much, which is not what we want for ESLs"

Rob Mackinlay (ER Audio):

"We have a 3.8 micron film which is proven to work well and has been sent to a number of ESL enthusiasts in your country. The response of these thin films has to be experienced to be believed"

Seldon D. Stokes (SDS Labs):

I've been rebuilding Quad ESL-57 and ESL-63 electrostatic speakers using some really nice 3.8 micron thick polyester film purchased from ER Audio. I decided to have a fresh set of aluminum perforated metal stator material powder coated, to try this super thin film. This film is roughly twenty five times tinner than a human hair. The mass of the 16" x 46" diaphragm is about 2.5 grams. After building a set of panels with this film, and listening to them, they turned out to be HARSH. It turns out that the ESL Information Exchange transformers have a bit of leakage inductance problem which is causing a rising treble response problem. This makes for the most detailed and revealing speakers I've ever heard, but a bit "teeth drilling".

Someone in the: http://hitechnetworks.net/bwaldron/testimonials.htm

I have experimented with other stuff. It sucks. I tried 3.8 micron film from another source. Working with the film was a real drag. It wasn't because it was so thin, either. The film did not shrink up tight. I was unhappy with the way that it felt,too.

Is the ER-audio Polyester 3.8 micron Mylar too?

Steve M: In one of your posts you said:

"The 3.8 micron ultra thin mylar membrane stops and starts quicker than any other cone material you care to mention (including any ribbon foil) so there is no smearing to musical notes, no overhang, no box coloration or distortion that I can hear..."

Is the ER-Audio Polyester 3.8 micron really a Mylar too?

Please give me some answers!


http://www.eraudio.com.au/ (ER Audio)
http://www.innersound.net/ (Innersound)
http://www.quadesl.com/ (SDS Labs)

[SY]

Mylar is just Dupont's brand of polyester. The only polyesters that can be Mylar are Dupont. That said, there are some other polyesters worth considering, most notably Melinex. PENs are also very worthy contenders.

My own choice of material is Clysar. But it can be tricky to coat- the surface energy is fairly low.

[shooter]

Another happy user of the ER audio Els3 loudspeaker, the 3.8micron film are not shrink tight with heat but pre stretched with measuring guage and glued. I highly recommend stretching the film on a piece of glass, Rob also sells the guage. Els3 are wonderful speakers, extremely fast and detail, they don't go down very low but I use a sub.

[michaelpage26]

Thank you guys for the reply!

Shooter:
Which crossover point do you use?
Also is the Tensioning Gauge of ER Audio doing a good job?
Is it included in the ESL III kit?
Have you compared your system with more expensive electrostats like ML, Innersound or Quad (and which models)?

Regards,

Michael

[shooter]

The crossover point I use is anout 80hz, I have extensive experience with Quad 63 when my friend had a pair, They did not make me want to sell my Apogees, I believe the ELS3 are more transparent, more detail and faster transient speed. they make my Apogee sounded slow, they have great sound stage , when you are out of the sweet spot they still sounded excellent, but when you hit the sweet spot it will let you know, there is no mistake about it. My friend who used to work at highend audio sales and manufacturing said these are the fastest and most transparent speakers he has ever heard.
The kit comes with all the parts you need to build the speakers except the lumber for the enclosure.
I strongly recommend using subs, my panel resonance frequency is about 45hz. I also have the bass equilization network from ER audio, it does make the speakers sounded fuller, but I think it might slow the speakers down a bit, I am planning to modify it with better parts.

[michaelpage26]

Thanks! That helps a lot
Could the 150hz crossover point be considered as high for TL with two Eton 11-581 with ESL III?
I mean that: Some say that electrostats lack dynamics of cone speakers.(and Steven M: I don't confuse the loudness with dynamics)? Is this happening in the whole Midrange-Bass region or only in the lower bass regions (<100Hz)?
Could that "problem" be fixed with a sub as it provides strong bass root , giving to the electrostat the real rythm and dynamics of the music? If i use a sub like the Eton TL could that make the ESL III play music like heavy metal (which I listen to in rare occasions)?

Sorry for the many questions one more time!

Thanks in advance!

Michael

[shooter]

If you have enough stable power, ELS3 are very dynamic.

[rick57]

Shooter

Could you elaborate on enough stable power:

I thinking of using them from about 200 Hz up.

I believe amp current is the key.

Do you think a 100 watt Aksa would work well?
Or a paralleled LM 3886 (60 W into 8 ohms or 106 W into 4 ohms).

Thanks

[shooter]

With electrostatic speaker, they need stable amp because of the reactive and capacitive nature, the impedance rise in the bass and drop to almost short circuit in the treble with high capacitance, many amp are not comfortable drive in those conditions, I have a 200w high current amp blew one channel. Although a 100w Yamaha receiver with protection circuit works fine, they will shut down once in a while when playing very loud with a lot of high frequency content, must be the low impedance in the trble that cause it to go to protection mode, I am using a 70w OTL tube amp with them with great result, you might want to consult with your amp designer to find out if your amp is stable into electrostatic load.

[rick57]

Thanks for the basics of the problem. However as I’ll only be using them (as stated) about 200 Hz up, and now probably only up to about 5 kHz, impedance rise in the bass and high capacitance in the treble are not an issue –it’s just the midrange.

I don’t have the amp, I want to know *what parameters & values* to get for a midrange as a healthy minimum. Eg min 25amps current?

eg anyone know if a 100 watt Aksa might work well?
or a paralleled LM 3886 (60 W into 8 ohms or 106 W into 4 ohms)?

and *would an Aksa or a LM 3886 be "clean" enough*?

Thanks