Electrostatic speakers?

[SIY]

How about ignorant?

Cut and paste from Oakeshott.

 

[JustAnandaDourEyedDude]

Cut and paste from Oakeshott.

Not having done any formal study of philosophy, I had never heard of Oakeshott before. But yesterday I googled a couple of sentences from the quote, and the quaint 1933 book (reprinted often by CUP) came up in google books. I read through a few pages, and judging from the fact that I was able to follow the arguments even though Google omits every third page, I would say that the writing is repetitive. Multiple uses of the word "vicious" regarding science points to a slant in the author's thinking. The book looks like a shaky attempt to limit the relevance of science to not just the universe of sensible matter and energy, but to a non-physical mathematical world of measurements that the author defines. This is even more drastic than a rejection of materialism, and "music to the ears" of subjectivists who believe they hear subtle effects that the measurements do not capture, I am sure. The other "modes of experience" in the book probably get into qualia, and related topics that stretch back to Plato's Cave, would be my guess.

 

[SIY]

Not having done any formal study of philosophy, I had never heard of Oakeshott before. But yesterday I googled a couple of sentences from the quote, and the quaint 1933 book (reprinted often by CUP) came up in google books. I read through a few pages, and judging from the fact that I was able to follow the arguments even though Google omits every third page, I would say that the writing is repetitive. Multiple uses of the word "vicious" regarding science points to a slant in the author's thinking. The book looks like a shaky attempt to limit the relevance of science to not just the universe of sensible matter and energy, but to a non-physical mathematical world of measurements that the author defines. This is even more drastic than a rejection of materialism, and "music to the ears" of subjectivists who believe they hear subtle effects that the measurements do not capture, I am sure. The other "modes of experience" in the book probably get into qualia, and related topics that stretch back to Plato's Cave, would be my guess.

“What science is, is not what the philosophers have said it is.” Of course, Feynman was an actual scientist, so what would he know about it?

 

[AdamG]

And to think as we hit page 20, this thread was basically DOA and then, like Frankenstein’s monster, “it is alive”.

 

[Blumlein 88]

That would take a pretty large room, I'd think. My modification was a rebuild of the frames, which made the front-to-back path significantly longer. Looked horrible the way I did it, but it worked. Someone more skilled with wood could pull it off and have it look decent.

Not that big a room.

If you put the speaker 5.5 ft from the rear wall, the back is already 180 degrees out of phase. Some of it bounces back and has traveled 11 feet. Double that and it reinforces wavelengths from the front of around 22 feet or about 51 hz. Works better in a concrete below ground basement than in a sheetrock and wooden frame structure above ground.

 

[carewser]

"Only $10,000"?

Apologies if I've missed some sarcasm

I was being facetious because in my world that's an insane amount of money particularly when you still have to buy amplification, a source, etc... and those Quad's were slightly used so normally they'd be $25,000/pair

 

[Frank Dernie]

Fellow pedant here...

Often overlooked are the oblique modes, which are the 3-D diagonal modes between maximally-opposite corners. These are the lowest frequency room modes.

I'm not sure that they are typically as strong as the three principle modes you cite, so maybe the obliques don't really qualify as principle modes.

I have never seen these and don't know how they could be generated, or sustain themselves, because in order for the mode to exist it needs a parallel wall opposite.
In fact one of the most effective ways I have experienced at minimising the excitation of room modes was to put the speakers either side of a corner and sit on the diagonal opposite them (not in the corner).
I have only experimented with this once, in a difficult room but it worked quite well, and is one of the ways in which a determined enthusiast can deal with minimising room modes whilst not using computer connection and not ending up with a neat room layout

 

[Hayabusa]

Would you distinguish between the "big panel sound" and something like an ESL-63 that radiates more like a point source? Or do they both have common colorations to you?

My last ESLs were 1+1s, which were sort of a pseudo-line-source.

Interesting question. I always wondered if the human ear would be able to hear the difference between a spherical (point source) or a cylindrical (line source) wavefront. This could explain some of the differences between point source speakers and planars.

 

[Kvalsvoll]

if the human ear would be able to hear the difference between a spherical (point source) or a cylindrical (line source) wavefront.

As you move away from the source, they quickly end up being very similar - a plane wave. At higher frequencies this happens only a few cm from the source. Close to the source, they are different in both intensity and phase between pressure and velocity potential.

They are also differnet in how sound attenuates with distance from the source - spherical looses 6db for each doubling, cylindrical looses 3dB.

If the radiation pattern changes with frequency, this will lead to frequency response being different at different distances from the source.

In-room, there will be significant differences to how reflections are created. At mid-low frequencies the early reflections are different and will cause the frequency response to be different.

So - in a room, it is audible, in anechoic/free-field it is not audible if you never move.

 

[Dialectic]

By some accounts, the reason the Quad ESL 63 took so long to "develop" is that Peter Walker was waiting for the expiration of someone else's patent on the electrostatic panel with concentric rings to mitigate beaming.

Was just thinking about this and had to track it down. The notion that Quad copied the design of an earlier loudspeaker patented in the United States by an MIT student is summarized here by the late Charles Hansen.

Here is the referenced patent, which expired on December 19, 1978. I've not read the whole thing, but a quick skim does not indicate much resemblance to the ESL 63. There is no mention of delay lines or concentric rings.

 

[Blumlein 88]

Was just thinking about this and had to track it down. The notion that Quad copied the design of an earlier loudspeaker patented in the United States by an MIT student is summarized here by the late Charles Hansen.

Here is the referenced patent, which expired on December 19, 1978. I've not read the whole thing, but a quick skim does not indicate much resemblance to the ESL 63. There is no mention of delay lines or concentric rings.

This does describe different sections of conducting rods which are fed different signals. It describes that the area of the diaphragm vibrating will vary with frequency and that the outer and inner conducting rods will not be in phase with each other. So it would bear some resemblance to what the ESL-63 did.

However, I've seen some papers from Walker with different ideas in mind. One was to have a strip across the end of the entire listening room. That strip would be made of thin sections each section part of a delay line. Sending signal into the left end would propagate across the strip to the right. Sending signals to the right would do the reverse. He had in mind feeding the left and right signals into this wide ESL strip for stereo. Which would cause the signal to travel across the room as if it had originated in each corner of the room. If I remember rightly this paper predated 1960. So Walker was already thinking in that direction.

 

[mjwin]

[...] I've seen some papers from Walker with different ideas in mind. One was to have a strip across the end of the entire listening room. That strip would be made of thin sections each section part of a delay line. Sending signal into the left end would propagate across the strip to the right. Sending signals to the right would do the reverse. He had in mind feeding the left and right signals into this wide ESL strip for stereo. Which would cause the signal to travel across the room as if it had originated in each corner of the room. If I remember rightly this paper predated 1960. So Walker was already thinking in that direction.

Indeed.

Peter Walker's thoughts on electrostatic speaker design, including more advanced possibilities, were eloquently summarised in his series of articles for Wireless World magazine in the issues dated May-August 1955.

The series begins with a clear overview of electrostatic loudspeaker principles, as used in the Acoustical Manufacturing Company's designs. In the third article (August 1955), Mr Walker outlines a more advanced design in which the capacitive loudspeaker elements were coupled with series inductances to form a transmission line. This is the genesis of the ESL63, and to the best of my knowledge is an original concept.

The apparent delay in release of the product was (from my personal recollection) due to both issues with avoiding resonance problems in a large diaphragm full range loudspeaker, and also in the availability of the necessary printed circuit technology to implement the concentric pattern. If I remember correctly, it was the high voltage and low leakage requirement for the pcb substrate which was problematic at the time, due to the paper/phenolic resin formulation typically used. I think that the introduction of FR4 glass fibre solved the problem.

Of course there's "nothing new under the sun" as is often said, but I think it's only fair to credit Peter Walker, and his colleague DTN Williamson, with this brilliant concept.

 

[misterdog]

Available for download here https://worldradiohistory.com/Wireless_World_Magazine.htm

Though the download speed feels like 1955.

 

[Pearljam5000]

Another issue with electrostatics lol

 

[Frank Dernie]

Another issue with electrostatics lolView attachment 108067

Well that is just another manifestation of the standard problem with cats!

 

[PaulD]

This one always gave me a laugh!

 

[misterdog]

Available for download here https://worldradiohistory.com/Wireless_World_Magazine.htm

Though the download speed feels like 1955.

Just needs someone good with IT to collate all the articles into a single PDF

 

[anmpr1]

"Science is the attempt to conceive of the world under the category of quantity. ..."overly verbose" or "dry and succinct"?

How about ignorant?

Cut and paste from Oakeshott.

This is certainly off topic, but it is the weekend.

Ignorant? I would not call him that. One might disagree with his ideas, but he was not an ignorant man. He was also pretty clear in his writing.

First, Oakeshott was not primarily concerned with the philosophy of science. So to mention him in that context is a little oblique. Nevertheless, in reference to 'quantity' his characterization of 'modern' science (as opposed to its classical and/or scholastic derivatives) is certainly valid as far as it goes.

Also, his interest in the topic turned on his argument that the method of empirical science cannot be generalized to include disciplines such as history or politics. I think that was his main point in bringing it up. For Oakeshott, scientism (the idea that an empirical scientific method based upon mathematics is suitable for generalized employment outside of the hard sciences) was wrongheaded.

Oakeshott argued that what we call scientific inquiry in the hard sciences is essentially the search for an explanation of a contingent empirical reality that can be grounded, or justified, ideally. An attempt to make empirical knowledge certain... by way of necessity--in its case, using mathematics or quantification in general as an explanatory foundation.

This kind of rationalism can be contrasted with the strict empiricism of some of his earlier British comrades (especially Hume--for whom scientific knowledge based upon causation and induction was essentially impossible since, for the Scotsman, relationships based upon experience are contingent, whereas mathematics concerns relationships of ideas which are necessary; therefore, in Hume's opinion, the two don't and can't mix). Here, Oakeshott was more in the camp of the continental rationalists stemming from Descartes.

Oakeshott was in any case more known (I'd think) as a scholar of political theory, especially Thomas Hobbes. That is how I always encountered him. His book, On Civil Association, can be recommended (along with Strauss' Political Philosophy of Hobbes and Eric Voegelin's The New Science of Politics) as possibly reinvigorating the study of the influence of Hobbes as he relates to the genesis of liberalism.

Back on topic, I do not know what kind of speakers he owned, but a single (original) Quad, listening in mono, would be my guess.

 

[Wes]

He is ignorant of what science is and how it works. Go re-read his stmts. above mine.

 

[Dialectic]

Not having done any formal study of philosophy, I had never heard of Oakeshott before.

And you would be unlikely to have heard of Oakeshott even if you had done formal study of philosophy.