Electrostat transparency from conventional speaker

You might want to consider Spicas. My local dealer said that the Angeluses came closer to the sound of Quads (which he also sold) than any other dynamic speaker. Of course, this was many years ago, and the state fo the art has certainly progressed.

hales, dunlavy, duntech, allison, older AR are five examples, but certainly not the only ones. these brands and others sought a flat response from top to bottom. no exageration of the frequency range and since they are not ported, the roll off in the lowest frequencies is quite gradual. they are generally not as fussy about room placement too. transparency, flat response, tonal accuracy, and if the recording has it....real weight and dynamics...the spica 50 and the chapman t7 are two others. it is more popular, even at the highest end of audio to woo the listener with a combination of detail and staging. this makes for a great demo, but also makes for an unsatisfying pair of loudspeakers when you get beyond audiophile recordings.

The Chapman T-7's are uncanny, out Quading a Quad, if you can find a pair.

>Only reason people tolerate electrostatic speakers today is because they are dipoles, thus they are a functional 4 channel systems or primitive surround sound system (2 direct ch., 2 delay ch. (see audioK's post)

The physics do not agree with common sense. Although direct radiating speakers only have drivers on their front-side, sound waves in half the musical spectrum are large compared to domestically acceptable speakers so there is substantial off-axis radiation, even behind the speakers. Within the human vocal range, a mezzo produces foot-long waves at 1000 Hz and a barritone hits eleven feet at 100Hz.

The same wrap-arround occurs with the front and rear waves of dipoles. Since they are 180 degrees out of phase, they cancel when they wrap arround and meet. Dipole off-axis response is reduced by 20 log cosine alpha dB compared to the direct resonse. This means -3dB @ 45 degrees, -6dB @ 60 degrees, -12dB @ 75 degrees, etc. There is substantially less (1/3, -4.5dB) total power radiated for a given on-axis SPL compared to the ideal monopole which a conventional speaker approximates with decreasing frequency.

So dipoles generate less ambiance than conventional speakers and their reflections in the typical listening room are less deletrious. In my 13x19x8' room with the listener 11' off the front wall and speakers 4' off the front wall 8' apart measured from the tweeter dome apexes toed in to face the listeners, dipoles generate first reflections -6.5dB below the direct sound 4ms behind it off the ceiling and -11.2dB below 3.5ms behind off the side walls. In the range where the direct radiator doesn't have rear-ward output, the dipoles have a second reflection at -6.8dB below and 9ms behind. This is definately preferable to the direct radiators first reflections at only -3.5dB/4ms and -3dB/3.5ms.

The way to achieve electrostatic transparency with a dynamic driver is to skip the box. Dynamic dipole midrange like that found on the Linkwitz Orions is more similar than different to the planar speakers, although the sweet spot is much wider and placement less finicky.

"The physics (theory) do not agree with common sense"

But the measurements do, just measure 1m from the back of the speaker and 1m from the front of a Dipole and a Monopole then measure at the listening position. Compare them, then we'll be in agreement about How a Dipole really works in a room and what all that math you copied equates too. Please note the high frequencies are the exact frequencies that matter most in why I made my 4 ch. comments (Orions are only dipoles to 1440hz>24db/oct). Which is why Electrostatic Dipoles image overly large and are vastly different in their behaviour to the Orions. SL's experience with center channels is exactly why you don't want Dipoles for surround and why they make better 2 channel speakers than Monopoles.

Not all of us are on the SL train especially when it comes to surround sound! The Orions are great speakers but...

...I'd like to note CDwallaces post said "conventional box speaker", so my rec's are limited to the restriction placed by the original post.

have a good one