Hi microstrip
“The polar graphs of the SH-50 really look impressive - if it sounds like a 100dB/W ESL63 it sould be an impressive speaker!”
Thanks, I would like to think they do share a similar sound with the dynamics of a horn, the result is similar although the method is different.
The 63 has a particular resonance, a place in my heart for me, it did open my eyes to a different intention, a different way of thinking than I was aware of.
That was the first time I had ever thought about radiating a sound is a three dimensional process and at best we measure one location, here a speaker was deliberately producing a part of a simple sphere. If you did that, then the signal IS identical or close everywhere on the front surface. What I call spatial distortion is the degree that surface is not uniform, not identical.
One way a loudspeakers spatial coloration can be “heard” is if one listens to the signal an omni mic picks up vs the signal signal.
One of the ways we have refined the speakers (more of a sanity check of the right direction) is to make generation loss recordings where music is passed through the speaker and then recorded with generation one colorations. That is repeated each time multiplying the colorations and errors (with no errors one has no generation loss). By two or three generations most speakers are unlistenable. While this was fun because you can hear what’s wrong very clearly, the generation loss test do not give one any guidance so far as what to fix and how.
Anyway, you can’t tell much but this video might be fun, it is a much larger speaker used in sports stadium sized listening areas (2nd link) .
It is also a coherent single source and so at least that part can be heard in a recording of it.
At the farthest distance here (they measured later) camera was 700 feet, the camera a Cannon t2i, audio is straight from the camera.
http://www.facebook.com/video/video.php?v=1717077460850&oid=126113687424773&comments
http://www.lightingandsoundamerica.com/news/story.asp?ID=-4B8JO6
“Although my current main speakers are the Soundlabs I still keep the ESL63 - it has been a constant in my system for 30 years, sometimes in the primary system, others just as a secondary.
Used within their limitations they are the most lifelike speaker I have owned.”
I can imagine the SL’s (the only ones I have heard were very large driven by huge OTL’s) would be as hard or harder to drive than my home made panels (which were harder than the 63’s and Accustats). That size would provide a LARGE amount of directivity compared to most speakers and so the near field is much larger than usual (cones and domes), normally that would mean your imaging is likely very good from much less room sound like the setup I heard. Fwiw (producing the lowest level of room sound) is the reason directivity is so important in larger rooms, the larger the room, the smaller the absorption is relative to cubic volume. IE; put the sound only where the people are.
I had built a direct drive tube amplifier once but used a pair of old Mcintosh M-60’s most of the time.
Funny, I worked at a TV store in High School in the early 70’s, people were trading in the Mac stuff for the new Panasonic hifi gear (pre Technics).
I used to buy the traded in mac stuff from the store for myself (which was as close as I could ever come to buying anything cool).
To go back in time and buy a dusty mac 240 and mx 110 for $20 again ahh.
The issue was /is ESS speakers are a parallel capacitive load coupled through a transformer who’s high end response is governed by series inductance. Like tube output transformers, the best step up transformers are not simple. Back then driving my home built panels, SS amplifiers tended to sound bright or brittle or even icky while the Mac sounded fine. What amplifiers do you use?
Best,
Tom Danley
