The Shure V15 V with a Jico SAS/B stylus VS The Soundsmith Hyperion MR and Lyra Atlas SL

Or, as Sir Thomas Beecham said "The British don't like music, they just like the sound it makes"

@mijostyn Ha, Wagner invented the "wall of sound" concept so beloved of pop promoters like Phil Spector.

Wagner’s ’temporary’ concert hall in Bayreuth is still the world’s biggest wooden building, as far as I know. Having a full orchestra effectively buried under the stage with the sound emanating from a wood lined slot must surely produce the antithesis of imaging.

Mind you, I have never been to any large-scale classical music performance where I could pin-point any instrument on the sound-stage with my eyes shut.

@lewm I think unamplified jazz and classical are the only genres which provide a live 'reference' against which recorded sound can be judged.

My local concert hall is in the Sydney Opera House which has just undergone a 10-year A$300-million refurbishment.  This included about A$100-million to fix the acoustics of the concert hall.  I was at the first concert after it re-opened, and the change is quite remarkable.

My partner lives in the suburb that hosted the Sydney Olympic Games so we sometimes go to outdoor concerts in the main stadium.   Groups like Queen have awesome sound reinforcement systems, but many are very poor.

Ironically the opera hall in the Opera House is undersized (it was switched during construction) so we sometimes go to amplified opera performed on a floating stage looking across the harbour.  Crazy when you think about it!

@mijostyn Peter Walker of Quad used to do A / B demonstrations of his electrostatic loudspeakers, which were hidden behind a screen. Often B was a live string quartet.

I am not talking about dynamics in what follows, but imaging! Not just imaging, but the pin-point imaging loved by reviewers but absent in my opinion from any un-amplified live music venue.

The role reflections play is remarkable, both from the surfaces of the recording venue and of the listening space. I will always remember the utter strangeness of sound without echo.

First time was in a big anechoic chamber (anechoic = no echo!). Totally disorientating. The second time was sitting on top of Iron Knob, an abandoned ore mountain looking over the Nullabor Plain (nullabor = no trees). The Nullabor Plain is possibly the world’s largest infinite baffle. The railway line goes straight for 297 miles. There’s nothing to reflect anything, except the ground. There were no birds, no rustling of the wind, just an occasional dust trail from a vehicle 50 miles away on its way to Perth. Absolute silence and equally disorientating. My conclusion is that a great deal of what we normally hear is reflection.

I have not been to the Boston Symphony Hall, but agree that logically the ideal sweet spot has to be on the centre-line. But how far back, or even forward? One obvious singularity is where the conductor stands. Unfortunately, the conductor is almost always too close to the nearest instruments to hear the intended balance. Where else? Maybe where purist recording companies put their microphones (I am thinking Mercury)?

Norwegian 2L recording engineer Morten Lindberg recognises that all recordings are an illusion. Why not put his multi-channel microphone tree where the conductor normally stands, but push the instruments back into a circle where they carry equal sonic weight from the conductor’s position? Works for me!

My favourite 2L recording is probably Australian pianist Percy Grainger playing Grieg’s Piano Concerto, recorded way back in 1921. The piano was originally recorded as piano rolls and is replayed on a modern piano with a symphony orchestra recorded in immersive sound.

In many other ways Percy Grainger was a century ahead of his time, but that is another story.

@mijostyn 

"I specified the distance, 10th Row"

True, and many people would roughly agree with you.  But there is nothing mathematically special about the 10th row.  Why not the 9th or the 12th?  Or an equal distance behind the orchestra?  I hear your advice but want to also make my own mind up.  It is well worth reading Morten Lindberg's philosophy of the art of recording About 2L (Lindberg Lyd).

"It takes a full range line array from 18 Hz to 20 kHz"

If the alternative is separate dynamic drivers, then I understand where you are coming from.  But there is an alternate solution which should be better. The problem with a line array is the arrival times from the top, middle and bottom differ, which produces wave reinforcement and cancellation at various frequencies.  One symptom is that your head has to be at the 'right' height for the audio image to snap into place.  A secondary issue is that the path length differences are accentuated by reflections from room surfaces.

The solution I prefer is the virtual point source electrostatic panel invented by Peter Walker of Quad in 1963.  These panels have all the virtues of other elecrostatics, plus the point-source.  Most people including reviewers don't really get how the virtual point source works, so here's my interpretation. 

Imagine a point source of sound waves one foot behind a flat sheet of mylar.  As a wavefront starts to radiate from the point source, it first contacts the center of the mylar sheet, then progressively expands outwards in a full circle which grows in diameter.  The geometry and timing are totally determined by the speed of sound.

Peter Walker's design drives the mylar sheet electrostatically with a set of concentric anode rings carrying the audio signal.  The signal is delayed slightly to each successive ring, so the net effect (except in the plane of the panel) emulates that point source of sound a foot behind the panel.

It is not immediately obvious why this should sound good, but the answer lies in the coherence of both the direct sound and reflected sounds.  This speaker and its descendants are widely recognised as the most accurate speaker.  Note I did not say best!  For one thing, they do not play particularly loud.  When my ESL-63 pair was working, I got them louder by relieving them of bass load by using a pair of Duntech Thor sub-woofers.

Duntech was the brainchild of US physicist John Dunlavy, who moved to Australia and designed and built his high tech Sovereign speakers here.  Above all, they were designed to be loud and time-coherent. The reference speaker he used was the Quad ESL-63.  He designed the Thor to go under, which also raised the ESL to a better height.  When he returned to the US, he launched Dunlavy as a more affordable brand.

Later I replaced the Thor sub-woofers with an 18" Velodyne servo-controlled unit which can go very deep.  It comes with its own microphone and equalisation capabilities. Time coherence disappears as an issue at the long wavelengths of deep bass.

When my ESL-63 speakers started to fail, I replaced them with ESL-2905 which are identical except they have six panels instead of four, to give more bass extension, and are tilted slightly back.  This FRED (Full Range Electrostatic Doublet) goes quite low from 32-Hz to 21-kHz -6dB.  More impressively the harmonic distortion is quoted (100-dB on-axis at 1-meter) as 0.15% above 1000-Hz, 0.5% above 100-Hz and 1.0% above 50-Hz.

"To get the best image the channels have to be equalized separately and have exactly the same response curve so that the volume of the two channels is exactly the same at all frequencies between 100 Hz and 12 kHz. No two speakers are exactly the same"

The final quality test for Quad is to position a reference speaker and the test exactly equidistant from a microphone. A square wave (which theoretically contains all harmonics) is played through one speaker, and out-of-phase through the other.  The speaker passes if there is complete cancellation, that is to say no output from the microphone.

"Then you put them in different locations and they become very even drastically different".  

Peter Walker made a big thing of getting the room eigenvalues right, whatever that means.  But once the speakers are positioned, you can walk around several paces without losing the imaging.  When you get close to one speaker, you can hear the sound coming from a foot behind, even when you move behind the speaker.  There is meant to be a null in the plane of the speaker, but I have two ears, and they are never both in that plane.  It is quite uncanny.

"IMHO every audiophile should have a USB measurement microphone and an audio program for their computer".

That's what I am doing with my Garrard project.  Measuring every change when playing a silent track!  One of my cartridges is a Shure V15 type III which vaguely keeps this on-topic!

Once again we seem to be in violent agreement on most things ...

Wow, this is getting interesting!

Hopefully this is my last quote from Peter Walker of Quad on the subject of speakers: "Anybody can build an electrostatic loudspeaker.  The trick is to build one that lasts" or some such.  

In the 18 years between inventing and releasing the ESL-63 to the market, Peter built in many protections.  The most effective, in my opinion, is an incipient ionization detector that senses when sparking is about to occur.  Other measures include reducing the instantaneous signal voltage when it gets to 40-Volts and shutting it down at 56-Volts.

A very influential person in the modification space was the founder of SME, Alastair Robertson-Aikman,.who tried stacked ESL-63 speakers (stacked at right angles).  He beefed up the frames, and tilted the panel back slightly.  Quad made a beefed-up ESL-63 for studio use, and Robert's ideas found their way into subsequent Quads like the ESL-2905 which I use now.  Ironically, despite the massive weight bolted to the base, the standard floor spikes, the reinforced frame and the stressed triangulated support bar at the rear, the panels themselves still float in a foam surround.

My source, apart from general reading and personally meeting Peter Walker and pulling apart and rebuilding ESL-63 and ESL-2905 speakers, is the book by Ken Kessler which is included, along with white gloves, with each pair of ESL-2905 speakers.  The square wave test reportedly caused over half the production to be rejected.  Production has now moved from England to China, where much more attention is paid to details of assembly.  For example, every screw for the grills is also cemented, and every wire is hot-melt glued wherever it traverses a slot in the panel frame.  The Chinese have not been as successful with the adhesive used to attach the mylar film, and most of my panels have needed repair over say 20 years There are 12 panels per pair.of 2905, 8 for 63s.

@lewm 

"Like I said, in my opinion Quad 57s are best if you remove the complex electronics that Walker implements in order to make the panel act like a point source. Then a stacked pair (or triplet) can act like a line source. Hearing is believing."

The ESL-57 was never designed to emulate a point source.  That innovation first came with the ESL-63 released about 25 years later.  I know of no other speaker family that uses annular electrode elements and time delays.  Time delays are implemented with about 12 miles of wire between elements.  It would be much easier to do today with digital signal processing but you would need an amplifier channel for every ring, that is eight per speaker!

The original ESL most closely resembles a line source, albeit lined sideways not vertically.  The slight vertical curve suggests vertical stacking as in a modern stadium PA system

@mijostyn 

"Dipole subs do not work well, I have built and tested them. No matter how heavy you make them they shake and the cancellation effects along with room modes create wild frequency response aberrations."

Plenty of speakers use dynamic drivers mounted back to back, usually with their cages rigidly fixed together. Newton's Law of action and reaction ensure that dynamic forces exactly cancel.  One example is the sideways facing woofers in KEF's Blade, which is designed to act as a point source, but unfortunately is out of my price range!

@stereo5 

"I bought the Shure V15-4 body and a new Jico SAS with the boron cantilever.  I love it!  ...  It is also better than my Audio Technica VM540 MM cartridge."

I missed your post in the off-topic noise (I plead guilty).

I have a Shure V15 type III and am just getting back into vinyl.  Was about to buy the Jico SAS / boron stylus, but could get the AT cartridge complete at the same price.  My Shure has the hyper-elliptic stylus.  Can you please describe the differences you are hearing?

@mijostyn

I did not mention dipole nor bipole! The Quad ESL-63 was called FRED as it is a Full Range Electrostatic Dipole - the rearward bass radiation is out of phase, since it comes from the same plane as the forward bass. FRED is logically a single driver but is manufactured as four adjoining panels.  The ESL 2905 has two additional bass panels, making four bass panels per speaker.

The Gradient subwoofer designed for the ESL-63 had one forward and one rear facing driver, but they were offset, not co-linear. The Duntech Thor had a single driver and had to be spiked to the floor to provide a semblance of stability for the ESL-63 it piggy-backed.

It makes sense to stack ESL 57 speakers vertically, but not the ESL-63 and later models. That would have introduced another point source to cause cancellation and reinforcement interferences! But if one could align them so the apparent sources one foot behind the plane of each speaker were in the same spot, you would get a bit more volume. You might even manage three or four aligned to that point source ... thereby creating a true Bipole from equal Dipoles.

@dogberry

@mijostyn

I bought an 18" Velodyne servo-controlled subwoofer to replace my Duntech Thors, back when my main speakers were Quad ESL-63. One undoubted advantage is that, by relieving the Quads of low bass, they can play much louder before their protection circuits come into play.

The bigger Quad ESL-2905 has about twice the bass panel area, and does not really benefit much from the Velodyne, which ticks by on level 3 out of 60. Most of what I play is orchestral and the only instruments that go really deep are organs (and maybe venues?)

Oops, I forgot the revolutionary Australian Stuart and Sons 108-key piano which extends the 'normal' piano range by two octaves, all the way down to 16-Hz.  Those low strings add sonority even when playing standard repertoire. The bridge design provides downward rather than sideways coupling, and the pianos are much brighter than popular European heavyweights.

@mijostyn My Velodyne 18" subwoofer is digitally controlled, with digital crossover and servo control of the cone for under 0.5% harmonic distortion.  It has 8-band parametric equalisation and 1250-Watts RMS power.  If I am not careful, it rattles the windows and brick walls too much.  It adds about two octaves to the Quad 2905 but most of that is felt, not heard.  Like you, I am a big fan of walking around to see how the audio image holds up.

On swept tones, the sound is dreadful as various room modes kick in.  Additional subwoofers would help, but musically I am in my own sort of heaven!

Ah, so much to take in.  Yes, my Velodyne has stereo high pass digital filters which is how I relieve my Krell / Quad ESL-63 / ESL-2905 of having to play low bass.  It is also old enough to have a pulp/paper cone but if the servo mechanism is good enough, who cares?  The only things stopping me adding more are: the cost; the space; the fragility of my home; the fragility of my partner; the neighbours and ROI.

The original Quad ESL is often known as the ... ESL.  But it is totally different in concept, design and implementation to the later Quad ESLs which have factory designation not less than 63.

The original ESL, aka ESL-57, uses a curved panel (much later this was apparently "invented" by Sound labs) to give an approximation of a line-source, albeit horizontal.  Like modern stadium systems, these can be stacked vertically.  Stadium so-called line source systems are curved in the vertical dimension to get them to emulate a point source!  It is of course rather hard to bend a flat panel in two dimensions simultaneously.

The ESL-63 and later models use fancy electrics and shaped electrodes to get a truly flat panel to emulate a point source.  It makes no sense at all to stack them, nor to remove the electrics which are their unique raison d'etre in my opinion.

@lewm Yes, the Quad 57 (your nomenclature) is indeed curved in the vertical dimension, which effectively focusses the sound on a horizontal line behind the speaker.  Most other speakers claiming 'line source' have a virtual line which is vertical!  

We now recognise the 57 as having three panels in a d'Appolito configuration, though unusually this is horizontal with a central treble flanked by two bass panels. Get off-center, and the bass panels start to differ in path-length, meaning there is a very small sweet-spot.

When the Quad 57 was re\eased in 1957 it was just the ESL.  Sound Labs "The Complete White Paper" states "The electrostatic speaker art was in its infancy when Sound Lab started business back in 1978" which is a bit rich considering Quad sold 54,000 pairs of the original 57, starting 21 years earlier.  I have many other quibbles with the white paper, especially when it groups dynamic speakers as point sources, which most certainly aren't.

Only the ESL-63 and later had the radiation pattern of a point source.  Whereas the 57 has a very small sweet-spot (sideways!) speakers that emulate a point source have a very large listening area.  The ESL 63 is often reported as the world's most accurate speaker, since it has a very light diaphragm, effectively no cabinet coloration, no crossover colouration, and a coherent radiation pattern with no cancellation / reinforcement interference patterns if reflections are ignored..  The 2905 has amplifier-like distortion measurements.  And if it doesn;t play loud enough for you, you can just sit closer!

Note that I am not claiming it is the world's best speaker, just very accurate.  Peter Walker's perfect amplifier is "a straight wire with gain".  The 63 and later aim for the same neutrality "If you don't like what comes out, pay more attention to what goes in" he said.

@mijostyn

"Now, what you are talking about is a co-axial point source which has absolutely no advantage over non co-axial point source speakers that are spaced closely together until you are a foot from the loudspeaker."

I beg to differ.  Where did the foot come from?  Whenever two separated sources play the same frequency (eg in cross-over regions) there is reinforcement and cancellation interference, as explained and animated here Discover the Surprising Flaw in Center Channel Speakers (youtube.com).

"In doing the variable diameter point source Quad was trying to improve dispersion characteristics at high frequencies"

The diameter does not vary - it is fixed by the speed of sound as it radiates from a virtual point.  Mind you, the stators are only static in the mechanical sense.  Electrically they carry the varying signal.  The moving membrane confusingly carries a static electrical charge.  I think one of the problems Quad tried to address was the cancellation and reinforcement interference experienced from different parts of a large panel.  They deliberately reduced the high frequency dispersion pattern, in ways I do not understand but probably in the delay circuitry.

"My assessment of modern Quads is there are dynamic speakers that outperform them in many ways resulting in a better listening experience particularly at levels above 85 dB"

Agreed.  I prefer my KEF Reference 1 at high levels.  These look like a two way speaker, but have two concentric drivers handling mid and upper frequencies.  Modern recordings seem to have more high-level transients, which trip the Quad protection circuits!

@dogberry 

"Not really a problem if you obey the instruction manual that says to use (an) amp(s) of 40-100W power and no more. As you may recall, I have replaced all the panels in my 2905s, and while the older panels were short on glue, it was the case that one would fail and start to arc after playing too loudly."

I still have four out of twelve panels in their original condition.  The rest have been reglued (really much more than that as it involves new mylar and new slightly conductive coating, plus proper tensioning).  Panel failures have been revealed by a slight murmuring noise, or popping as a spark flies!  I have also had a high voltage failure in one speaker - the high voltage is on the same circuit board as audio.  In the end, I made up a piggyback board to produce 5.25-kV.

Initially I used a Quad 405-2 100-Watt amp, basically designed for the speaker.  Later I switched to a lower power amp, the Krell KSA-80.  Well, lower power when measured into 8-Ohms, at just 80-Watts RMS.  The Krell is about 9 times larger, but only 4 times heavier, than the Quad, which made 100,000 405-2 amplifiers, on top of 64,000 405 ones.

In my experience, transients tend to be faster on SACD, BluRay audio and 4K disks, for example West Side Story, Spielberg fashion. Any instantaneous input voltage over 56-V triggers the protection, regardless of amplifier power.  The Krell has an impressive slew rate!

@bdp24 

A couple of obvious issues apart from those @mijostyn has pointed out.

1.  They have two drivers offset spatially by a considerable horizontal distance, which will give rise to comb interference with frequencies in the crossover region

2.  They have a crossover!

The result according to the video is that they are very hard to position.  Coincident source speakers tend to be very tolerant of room positions, and have much larger listening sweet areas ...

@tomic601 "imo the 63, of which i’ve sold ( new ) and rebuilt 4 ( several times over… the troubleshooting flow diagram is necessary but not, NOT sufficient, certainly has virtues but is hardly full range for various musical tastes…"

At least the ESL-63 Service Manual has a very comprehensive fault-finding flowchart! The 2905 does not, so I use the 63 as a guide. The 2905 improves the bass by doubling the bass panel area, going down to 32-Hz -6bB and less than 1% distortion above 50-Hz at 100-dB and 1-metre.

Quad made systems for music lovers, not audiophiles. Hence the infrasonic filters reducing bass output in the 405 amplifiers, and the extensive and subtle controls in the 34 pre-amp designed to allow music lovers to tame flaws in their records. A music lover will tolerate poor sound, an audiophile would prefer silence!

@mijostyn "you need to learn more about speaker design. The foot comes from the wavelength at the crossover point. ... What you are succumbing to is lay assumption and as we all know assumptions are the mother of all f-ups"   

So now I know that the "foot" comes from your assumption about the cross-over frequency - some mother of an assumption, especially with 3-way speakers which have two crossover frequencies! 

Your next statement is equally flawed "If two drivers are closer together than 1/2 the wavelength at the crossover frequency they function acoustically as one drive".

This proposition fails when reduced to absurdity.  Imagine the two drivers are omnidirectional and 1/2 wavelength apart..  Then along the line of the drivers, there is complete cancellation!  And on any other position, except equidistance, there is some cancellation.  Hardly functioning as one driver.

From memory you have made equally odd claims.  One is that only the sound from the closest point of your Sound Labs reaches your ear.  Well, if that were true, you could just keep an horizontal inch or so of the panel, and ditch the rest.  (See the reciprocity principle below).  The idea behind your assertion probably comes from that White Peper which describes the radiation pattern like the bristles from a bottle brush, entirely in the horizontal plane.

But that is not true either.  If it was, there would be no radiation to reflect from the ceiling and floor, and no need for the speaker to reach either!

The White Paper makes a big thing of an "acoustical principle that we refer to as microphone/speaker reciprocity".  I would not dignify it by calling it a principle, but it makes the case that speakers should be positioned as far apart as the (two!) microphones were, and the incoming (microphone) and outgoing (speaker) radiation patterns should match. The aim is that walking around the listening room should give the same experience as walking round the recording venue.

Why then, does this principle not also dictate that the speaker should be positioned at the same height as the recording microphone, and approximate it in vertical dimension?  I don't like so-called principles where you pick and choose what applies.

Walk round a concert hall (unpopular with the rest of the audience) and you will find sound coming from every direction.  Elsewhere I believe you have said the soundstage should be entirely between the speakers, and anything else is because wall reflections have not been eliminated.  Get real, decent systems can, and should, throw a soundstage extending far beyond the speakers, because that mimics the original venue.

"Quad was trying to improve dispersion. Stick with your KEFs"

Seems as if you are unfamiliar with the ESL-63 and later Quads?  Quad deliberately reduced the treble dispersion to "improve" it.

@mijostyn 

"Do you realize that you have just noted that every great speaker designer is absurd, that the laws of acoustics are flawed. Don't listen to me. Get The Loudspeaker Handbook by John Eargle. It is written in terms most lay people can understand. Learn what you are talking about before you spew out ridiculous concepts. The British don't like music? I think you need to listen to V.W.'s The Lark Ascending"

Sir Thomas Beecham is a far greater authority than me, and I suspect, even you!  It was his quote.  If it were mine, I might substitute audiophile for British!

I have many copies of The Lark Ascending, and one of my favourite flicks is the Australian "The Year My Voice Broke" which uses it poignantly, and has just been reissued.  Vaughan Williams could write almost anything, from his Fantasy on a Theme of Thomas Tallis to his sixth symphony, which is exactly my age.  The latter opens with shattering intensity, swerves into jazz rhythms, and ends like Holtz' The Planets.

I note with some disappointment that you choose to criticise the person, rather than debate the specific technical points I raised.  For example, what is your answer to the complete cancellation of two drivers half a wavelength apart, which you claim act as one drive?  This is pure physics, simple to understand by anybody who knows what a sine wave is.

Of course, this really is a problem with almost all speaker designs, so not too many want to talk about it.

@lewm 

No, not if it emulates a point source!  But it is a problem for pseudo line sources.  I am not stupid enough to believe that any claimed line source really is one!

@mijostyn 

"I cannot imagine owning a speaker that could be so easily blown. In my hands it would not last 5 minutes. There is no excuse for a speaker to be so fragile. The materials exist today that can be used to make a totally bullet proof ESL panel. They existed back in 1978! Jim Strickland made a bullet proof panel back then. I can rap the diaphragms against the stators without any damage. The transformers are the elements that are potentially fragile particularly with amps that are clipping. I have blown amps and transformers but never the speaker itself"

No, in your hands they probably would not last 5 minutes, but you would really have to try hard to beat the protection circuits.  My two pairs of Quads have lasted about 20 years each before needing repair, which is much better than my bullet-proof Krell amplifier.

Yes, you can rap the mylar against the stators, but be aware that when powered, and for some time after switching off, the mylar carries 5.25-kV.  The stators carry no voltage until a signal is applied, but then can be fatal.  I always keep one hand in a pocket when near the high tension bits!

Unfortunately there is no Aussie distributor for Sound Labs.

@mijostyn 

I do know and understand that stuff, pretty much like the back of my hand.  Absolutely right, subwoofers should be put to work on long wavelengths, which often will be longer than the listening room.  They will excite room resonances and one benefit of having multiple subs is that they average out these resonances a bit.

Now are you saying that the longest distance between any two of your subs is four feet?  I am particularly familiar with the Duntech Sovereign where the blurb says it is "acknowledged by experts as the finest speaker in the world, certainly the most accurate".  Each speaker has seven drivers in a floor to ceiling D'Appolito arrangement, which puts 12" bass drivers near the floor and ceiling.  Base is quoted as down to 27-Hz within 2-dB.  A huge amount of effort was put into time aligning the seven drivers so if you sat at the right ear height, phase differences were less than 25 degrees.

Because time alignment is so important, vertical listening position was crucial.  Slowly lower yourself and suddenly a huge image came into focus.  A few inches more and it was gone.  That was in a very large demonstration room where wall reflections mattered less than usual.  I've mentioned before that the reference used when designing these speakers was the Quad ESL-63.

Yep, the wavelengths tweeters should handle make it unwise to use more than one (why does Infinity spring to mind here?).  Tweeters can be made coincident (concentric) with mid-range drivers, as was done by Tannoy and is now brilliantly executed by KEF.  I have not heard the Tannoy re-incarnation by Fyne.

@mijostyn "What is a pseudo line source?"

A true line source speaker does not exist, any more than a true point source speaker can actually exist.  If they could, the energy they emit would have to be crammed into an infinitely small volume, a singularity.  Singularities are hated in physics theory.  If you can get an ounce or two of matter and cram it into a very small volume, you pretty much have the preconditions for the creation of another big-bang and a new universe.

Ribbon speakers probably come closest to a line source, but big electrostatic panels have to use geometry and / or smarts to give the illusion they behave like a point, or a line, somewhere outside the plane of the panel.

Countries with small populations like Australia, New Zealand, Norway, Denmark, Slovenia can all make really good equipment.  Australia even invented WiFi.  But there is little government support or venture capital for start-ups.  The volumes are low, so prices have to be high.

The flip side is that there are very few import duties anymore.  The car industry is wide open to imports.  Ford, General Motors, Chrysler, Toyota have all stopped local manufacture quite recently.  Chinese cars will dominate very soon!

In general I can import stuff and save about 25% compared with buying the same item locally, after allowing for transport costs.

@mijostyn According to their website, your so-called ’real’ line source speaker tries to emulate the behaviour of a virtual line source situated about 3 feet behind the panel, just as Quad ESL>63 try to emulate a point source a foot behind the panel. A true point source radiates spherical soundwaves evenly from the point in every direction. A true line source radiates cylindrical soundwaves evenly from the line.

So are your subwoofers actually 12 feet from one end of their line-up to the other?

Does not having a rear wall mean your listening area radiates into free space?

I only mentioned Duntech Sovereigns because they were a D’Appolito configuration with careful time alignment that exhibits dreadful interference, despite being engineered to sound like a Quad ESL-63. John Dunlavy was a US physicist specialising in radar and wave propagation. Duntech speakers are still being built in Sydney, I suspect mainly for the Asian market.

@lewm 

So it seems as if the four sub-woofers are spaced in a line with 4 feet between adjacent ones.  The far left and the far right are thus separated by about 3 x 4 = 12 feet..

For the record, Quad ESL speakers, apart from the original, do not beam like crazy.  In fact, quite the opposite.  This is because they have time delays so the entire panel does not behave as a 'moving piston'.  It seems to be a hard concept to grasp, but there are heaps of polar dispersion diagrams in the brochure!

The good thing about 0-Hz is you only have to do it once!

@mijostyn 

ESL in Australia normally means English Second Language, and represents the quarter of the population who don't speak English at home.

I try to use English as a Scientific Language with precise meaning.  Seems we are from two nations divided by a common language.

Anyway, it appears both countries will stop today for important races.  Yours is for a President, our country stops for a horse race!  Australians are the heaviest gamblers in the world, even the Sydney Opera House was paid for by a state lottery ...

@mijostyn "Do you have stadium concerts down under? If you go to one you can hear midrange/bass line sources. The sound is usually awful. I do not bother any more"

Yes, there was a concert last night at Sydney Olympic Park, Main Arena.  Seats over 80,000.  Could hear it from home!  

We went to a Bushfire Aid concert there a couple of years ago.  Queen and Adam Lambert had played the night before, and let every other gig use their sound system.  We arrived early and could hear kd lang practicing hard to get her sound right. The sound during the first session was so bad overall that we found a beer garden outside and listened from a distance.  Later acts must have learned something because the sound became listenable, then good.  kd lang sounded brilliant and Queen finished off in their usual style with superb sound.  All from the same hardware!

Queen's Brian May is an astrophysicist in his spare time.  Fred Hoyle, who coined the phrase 'Big Bang' because he thought that particular origin theory was rubbish, worked out most of the nuclear reactions occurring in stars.  To Fred, a star was a one-dimensional problem.  Work out what happens on one line radiating from the centre and you have solved what happens on every line. 

Brilliant people can sometimes be wrong.  And sometimes conventional wisdom is overthrown by a single visionary, at which point everybody else becomes wrong.  Newton, Einstein, Hawking: each did this/