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Planar love

edited November 2013 in Audio Talk

Show us a pic or two of what you're listening to!

A technical (ish) question: why do people like planars? I've read that they have lower distortion but the measurements I have don't really say that. Is it because they are dipoles? (Can't really be just that.) Any links to erudite technical info on this would be appreciated!

PS my little ER mini panels are on the shelf for now. I'll get back to them at some point...

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  • I don't know why people like planars, something I've never understood, as I've never heard any that really jumped up and grabbed me unlike some conventional DR and horn systems. But I'd be intrigued to know why. The best I recall hearing were the Quad 63's, but it was on unfamiliar classical music.

    I suspect you may have to get invited to the homes of some that do love them and get them to put on the recording they think show off their best qualities and listen and try to get a handle on it. They are generally mongrels to measure, at least the large units because the impulse is smeared by the lastly different time of flight between the centre and the edges.

  • Hi Brett, perhaps I should have phrased the question as "what accounts for the audible characteristics of planars"? I generally like them.

    More later, too late now to think straight :(

  • Could it be they sound more like a point source .

  • Hi Mal, only the Quads have that. Oh, maybe Manger, haven't heard about them in a while. Most are very much not like point sources.

    I have a few theories now, will do some research.

  • Or is it one wave front of sound

  • Brett is right about the different distances from ear to the centre vs top or bottom of a large panel. What may not be appreciated is that compared to conventional drivers, the beaminess/dispersion of a panel means up close you are only getting a small section of the panel and as you move back away, you receive the energy from more of the panel (greater area). Apparently the decay through the air is half of a conventional because of that. That means nothing if the system is flat at the L.P but it is a difference.. For me the clarity of panels is impressive, not many tweeters seem to be as clean sounding, or is it the crossover?? There's no box resonance, but the best non-planar systems I've heard (Terry's and SGR's) pay attention to box resonance. Planar/di-pole cancellation creates a variable (by altering the sides of the enclosure) hi-pass filter, only shallow (6dB?), but no electronics. I intend to use that when integrating to my 8" woofer, somewhere between 160-220 Hz.
    My niece is coming over for Xmas and wants to hear the system again, so I need to get cracking with the changes to be ready by then. You'll all know when it's ready for an audition. There'll be bass this time as well.

  • I have huge planars. Magneplanar MG20.7, which are over 2m tall and approaching 1m wide. Before them I had Maggie MG3.6R and before that Acoustat III. Seems as though I have always had biggunflatuns.

    They are indeed buggers to measure, and I have never been convinced that I am giving the DEQX the right data to work with. I once tried measuring at 3m but ended up with too much 'room' in it. One day I may do the anechoic measurements again to get better data from say a 3m measurement (where the chair is).

    The larger Maggies have a 1.5m ribbon so that bit acts as a line source (down to about 1700Hz), while the mid range and bass panels are, well, panels.

    I am attracted by the transparency and elegance of the sound, and the fast reaction to transients. I think that the mass of the ribbon and panels have a fair bit to do with this. Lighter weights can be accelerated faster.

    Di-poles also have nulls at 90 degrees, so side wall reflections are greatly reduced. Then if you add the flatness of panels, the sound arrives at the chair in a sort of controlled beam/wall. There is a lot more direct sound than being in the normal reverberant field. They are not pinpoint imagers, but the stage can be wide and deep depending on the placement and front wall reflection.

    Being 'magnetic' and having a dedicated bass panel, Maggies have more going on down low than electrostatics

  • I like 'em.

    I really like Dr Good Vibes' panels

    Mal's heard 'em

    Mal?

  • edited November 2013

    One of my thoughts is that part of it is due to large surface area. And consequently, low excursion. While there's been some debate about "Doppler distortion", I found a paper on the subject by John Kreskovsky: http://musicanddesign.com/files/Dsitortion.zip

    I've printed it for further reading (and most of the mathematics is beyond me), but he does say:

    In any regard, the effect can be minimized by using drivers with large surface area and minimal displacement, although other compromises may be introduced. It is, perhaps in part, for this reason that large panel radiators, such as large electrostatic speakers, sound a little more natural that the majority of cone or dome type loudspeaker system.

  • GeeEmm said:
    I like 'em.

    I really like Dr Good Vibes' panels

    Mal's heard 'em

    Mal?

    What I hear at Doc's stay's @ Doc's :-)

  • ESL's need to be large to do low frequencies. Then the diaphragm itself may have resonances, so something (D'Appolito) needs to be done to kill those residences. damn this voice recognition software and my cold.

  • MALfunction said:
    What I hear at Doc's stay's @ Doc's :-)

    Ha ha, get back to bludging! :-)

  • Guys, feel free to invite the doctor IYL - http://audiofrequency.com.au/profile/invitations

  • 2 Dogs, The one's in the shed are 2.7 high and will do 20Hz full range the only issue is my dear wife, the first pair which are 3 way and at a mates place they were in the house for a couple of years.
    Mistake was to build a new pair and put the 1.8 pair inside.
    They will return !!!!

  • Hi Martin, do you have pics of your construction online? Would love to see them. Just wondering how you actually made them. Did you use parts from ER Audio?

  • Yes Martin do you have photos of the big 'uns ? Are they segmented ie n-ways ?

  • Will have to go through the files, no there single full range.
    JR no nothing from ER, the new emulsion is every good indeed and an improvement on what was last used the price on that film went up to $70 per foot from the USA before you could buy a roll 48" x 100' for $100 Oz.

  • Reassembled the ESL3s with new diaphragms last night.
    It is still a little amazing that after all the construction steps (glueing and coating etc)when you finally send signal to a panel that sound actually comes out, but it did. Yay!

    Next step is to measure and align the 8" driver underneath and build new, smaller boxes for them, since I intend to add separate subs.

  • Cool. Did you redo all six panels? How long does it take to do one?

  • you usually do more than one at a time else you are wasting mylar and your time tensioning it. There is room for 2 wide panels and the thin treble panel across the roll of mylar.
    To re-diaphragm, a panel - tear the old diaphragm off the panel half, then lightly sand the remnants that are stuck on the airgap spacer perimeter of the panel. 10 mins. Tension the diaphragm on a table/flat surface - 30 mins. Apply glue to the air gap spacer of the panel - 5 mins, then place it on the diaphragm and put weights on it - 5 mins.
    Allow overnight for the glue to take hold, cut the mylar sheet around the panel and lift the panel off the table with a tensioned diaphragm now installed. Prepare the electrolytic coating and apply - 20 mins. Allow overnight again for the coating to dry/cure, reassemble the panel halves and install back in the enclosure -10 mins.
    Most of a weekend is spent waiting for glue and coating to dry/adhere, but actual work time is a few hours.
    I

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