Who Has Built ER Audio's Acorn, ESL III or 505 ESL Kits?

[drivas]

I'm talking about these ESL kits from Rob Mackinlay http://www.eraudio.com.au/index.html

Had you had any prior experience successfully building ESLs?

On a scale of 1 to 10, with 10 being the most difficult, how challenging was it to build the Acorns or the ESL lIIs?

Did each speaker kit when constructed sound excellent the first time you applied power, or were measurements and tweaks to the stats, crossovers and/or bias supplies necessary?

So that I can make informed practical decisions about building one of these three ESLs-particularly the Acorns or the ESL IIIs-would you estimate your listening room size?

Using passive crossovers, what was the approximate minimum watts/per channel applied power where at 11 ft away you got ?? db SPL at 35Hz from the Acorns or ESL IIls?

I ask this because the amp that I would prefer to use only does 25 wpc 8 ohms/40 wpc 4 ohms. I realize that it may appear ridiculous to think of
using a low power amp to drive ESLs as they are hardly efficient speakers, compared to horns or some direct radiator drivers. But my room is ~ 16 ft x 14. And I’d only need 85db SPL at 35Hz, because between 70Hz to 7kHz I’d only want to listen between 55db and 50db SPL, respectively, as per the revised Fletcher-Munson curve. https://en.wikipedia.org/wiki/Fletcher% ... son_curves

Based on those conditions, would my amplifier have enough power to drive the Acorns and/or ESL IIIs, without risk of clipping or much audible
distortion?

On the other hand, if you instead built the 505 mini panels and used one panel per channel, did you mount it above something like a 15 or 18” woofer in an H-Frame open baffle?

If yes, and again using passive crossovers, what was the minimum watts/per channel applied power where at 11 ft away you got ?? db SPL at 35Hz?

It would certainly be great to hear one of Rob’s ESLs before building them, though I’ve never read from anyone who has not being amazed by their sound.

Any NY, NJ, CT, PA builders?

Thanks to all for your input and experiences.

[Jazzman53]

Hi,

I’ve never built any of the ER Audio kits myself-- but since on one else has responded to your post, I’ll offer up some predictions based on my experience building hybrid ESL’s of my own design.

ER Audio has a fine reputation, their prices are reasonable, and their designs appear to be well thought out so I would not hesitate to buy their kits. ESL panels are not hard to build and the ER panels look to be fairly easy for anyone with moderate mechanical skill. I’m not sure if those kits come with precut wood frames-- but if they don’t, you can be sure the woodwork would be the hardest part.

You can forget about 85db @ 35 Hz though. I’m guessing you would need to add subs to go much below 60Hz with any kind of authority.

A 25watt/channel amp might work but I’m thinking you’d need more like a 100 watts/channel to make those speakers really sing.

Charlie

[drivas]

Thanks Jazzman'53 for your reply. Judging from those here who have built them, there's little doubt that the Acorns are a very well thought out kit that truly rivals the $$$$$$ SoundLab full-range ESLs. True, 85db SPL at 35Hz is probably expecting too much; perhaps more like 75db at 40Hz, which seems to be what's implied here
http://www.eraudio.com.au/DIY_Speaker_K ... l_kit.html

I wish there were members around the in the US who would do things like Acorn group buys. That might make it affordable for some to at least get a chance to hear them. Just an idea. If only the kits were a bit less costly.