Do larger planar speakers produce more accurate sound?


Planar speakers generate sound pressure via vibrating membrane panels. The excursion of the membrane x radiating area= sound pressure. This would mean that for a given sound level, membranes have smaller excursion in larger planar speakers than in smaller ones. Does this mean that larger speakers will produce more accurate sound?

I am not talking about the obvious benefits of the larger speakers in terms of low frequency production, so let's not get into that.

128x128chungjh

yes in theory as well as in practice, although care and quality in implementation matters much in each

most importantly for me, the larger radiating surface gives a sense of ease in how the music is presented, it flows effortlessly, fills the space more uniformly, the music does not seem extruded or fired from a high pressure hose... purveyors of loud music wanting mega-slam and pulsing bass into their chests, rock and roll, electronica etc etc may disagree

It varies a great deal, but usually there’s a tradeoff for planars, and that is that they have poor frequency response performance which is traded for less room interaction and an amazing ability to project an image.

That reduction in room interaction is really _the_ reason for planars.

One can argue however that this reduction in room interaction makes the planars more accurate from a practical stand point. What good is a flat speaker that you can’t hear as flat they argue.

In terms of distortion and frequency response, I haven’t seen a planar speaker since the Apogees that would measure as well as a dynamic speaker without enhancements from DSP.

Having said all of this, planars are worth consideration because what matters is how much you enjoy listening to music, not which is more accurate.

To me accurate connotes measurement. As has been discussed quite a lot by enthusiasts and designers is that perfect flat speakers generally sound bad, sterile, unnatural. Planners tend to be very fast and are capable of reproducing sound well above the range of hearing, which through interaction of harmonics impact sound in the range of hearing creating a bit of magic… commanding one’s attention. I owned some form of planar… and extensively auditioned large Maggie’s and others a lot over fifty years. I switched over to dynamic about twelve years ago and my system started moving much closer to reproducing the nuances live acoustic music. But I also changed an upgraded all of my electronics so, I am not arguing that dynamic hold the top position.

 

With excellent no holes barred setups large planar, horn, as well as dynamic speakers can reproduce music that is nothing less than miraculous… showing little weakness in speed, tonal balance… etc. The strengths and weaknesses of each category tend to come out in less than ideal (by ideal… I mean great rooms and many $100K, top notch speakers an equipment supporting them), like in the systems most of us own.

If you only are interested in the academic question of frequency response, then I am sure someone will jump in with an answer.

 

Like most everything, there is always give and take.  There are so many parameters to consider.  So blanket  statements rarely hold water.  I very much enjoyed Magneplaners in years past and still do.  But I enjoy a non-planer speaker more.  

Folks, my question is less about planar vs dynamic; it is more about large vs small planar.

Large planar speakers are the only ones that can reach low frequencies. Little ones with dynamic bass drivers suffer from lack of cohesion through the audio spectrum. Little ones by them selves simply lack bass.  
 

 

I've owned two pair of planar speakers, Apogee Caliper Signatures back in the 1990s, and Janszen Valentina P8 now. The latter are hybrids.

The Apogees were more impressive in the sense of a larger than life image.

The Janszens are more flat (very flat!) in FR, and the dynamic woofers are extremely well integrated. So I prefer them. They have relatively small electrostatic panels.

 

The KLH Nines (which apparently nobody here has owned/heard) have excellent dynamic range and bass impact - even when used in single pair configuration! They were designed by Roger West (Soundlab) and Arthur Janszen back in the early Sixties. The Nines beat the Quads in the above performance areas due to larger surface area and power handling. Janszen sells restored pairs at very reasonable prices.

I can speak from experience, having a pair of KLH Nines in use since 1992. I used a variety of amps with them, including Bedini 25/25's and Futterman OTL's. With the power amp section of the Carver Receiver (125wpc) they had floor-shaking bass power!

I sure like Quads, I went from Quads to small planars 25 years ago. I was a big fan of Infinity's IRS Beta. I had them for 20 years or so. A guy that logs on AG fixed them for me. He is a VMPS guy, so I tried them. WOW for the money. Small planars and ribbons are the best for speed. Some are push only drivers, some are push pull. They show every flaw in my humble setup. WCF bass drivers. 19hz to 26khz so the specs say. They sure make my wife yell, MORE..

I can only answer your question based upon my ears and brain. I currently own Apogee Divas and Apogee Duetta Signiture ll’s. The Divas are substantially larger and go down to 25 hz compared to the Duetta’s 35 hz. The Divas sound more at ease and more lifelike at any volume. They also draw more current and have a lower ohm rating. They have greater impact on bass and drums. They make female voice and acoustic guitar and electric bass sound more real than any speaker I have heard, including everything at the Stereophile exhibition at San Francisco in 2006, including Wilson’s WAMM! Given the price of the WAMMs, I left the show not feeling the least bit that I was missing out on much. With that said, if given a choice, price not a consideration, I’d take the WAMMs for their overall impact. I haven’t had the benefit of hearing much newer stuff since.

I have Quad 2905's which create a circular pattern where as the Quad 57's have a linear pattern. If you were to take the panels apart from both speakers, you'd see a remarkable difference. Anyway, the 57's have the best sounding mid range but the 2905's are full range so it's good to have a pair of both.

I've owned a few planars over the years-Magneplanar i, Acoustat 1+1, Martin Logan Quest, and I've heard many iterations since.  I like what good planar speakers can do--create an enveloping soundstage, deliver clean and clear sound without being unduly harsh or artificially "forced".(no sense of unnatural edginess to the attack of the note).  But, like all speakers, there are some areas where they don't quite do so well, such as the requirement to be playing fairly loud to come to life (of course there are exceptions, like the Quad 57), and they are not as dynamic sounding as good horn-based systems.  The main issue is that most are not quite efficient enough to play well with the kinds of amps I like the most--low powered tube amps. 

It depends on the amp, of course, but many single ended amps and pushpull amps using just a pair of tubes like 6L6 or KT-66 deliver a full, lush sound without sounding muddy or sluggish.  Within their modest power levels, they are quick and dynamic and the sound is "dense"--harmonics are complete and realistic and not lean and thin.  I don't like most high powered tube amps with multiple KT88, KT120, KT150 because they tend to have a hard and brittle sound--the initial attack is artificially edgy and not as natural sounding.  Most high powered solid state amps sound lifeless to me at modest volume levels.  There is also an artificial sounding edginess to the attack of notes that  makes them a little bit brittle sounding or as some people put it, there is a "glassy" sheen that seems to be always present..  A good tube amp sounds relaxed and not edgy, yet when the music calls for it, they sound lively and deliver dynamics without sounding hard.

A decent 40 watt amp (e.g., Synthesis A40) should work with the majority of speakers, but, some panel speakers might require a bit more, depending on the setting and circumstances.  I don't rule out ANY speaker type, and certainly there are many that I enjoy even when driven by amps that are not my personal ideal amps.  It is just a part of juggling different strengths and weaknesses and making the right compromises.  I could easily live with something like the 30.7 Magnepans and an Ayre amp, although I still prefer a good horn system and my 5 watt tube amp.

I am not married to planar speakers, just to Clarity. What horn system do you like that can approach the clarity of planars?

I’ve had Planar speakers since the early eighties and still have a pair of Acoustat Model X’s. The midrange and the High-end are fabulous! The low-end, while accurate, has no push to it.  If I play the beginning of DSOTM loud, the heart beat goes rattle rattle, rattle rattle, because it can’t produce the umph of a traditional speaker. I’ve made a bunch of subwoofers over the years and have an old Audio Research EC-2 crossover, but have never got it quite right. The ripple of the Mylar is so much faster than a moving cone!

All the best!

JD

If by “clarity” you mean an absence of resonance that makes for a murky or muddled sound, panels and compression midrange drivers can be very good.  The very best compression drivers, such as those made by Western Electric, International Projector Company, YL, G.I.P., Goto, manage to substantially avoid nasal resonance that color some compression drivers and deliver clear, detailed and well textured sound with a sense of ease.  These drivers must be matched to very nimble and clear sounding woofers.  The woofers that seem to work best have light cones, and pleated paper surrounds.  The downside to such woofers is a limited excursion that mean they don’t deliver extremely deep bass.  This kind of bass is similar to that of large panel speakers which also don’t go extremely deep.   

Larger speakers play louder, but the Magnepan LRS is really a remarkable speaker and its accuracy is quite high, in my opinion. I am a musician (guitar, mandolin, uke) and regularly play five time per month with a group. My experience is with 3 models of Maggies, and a friend has some Martin Logans. I have built may and use open baffle speakers in my big system. Large doesn't necessarily mean more accurate.

I do not know if they do or not, but I really like my Maggies MGIIIa.  I enjoy the sound much more than box speakers.  I really do not care about deep strong bass; the Maggies produce nice clean bass and enough for me.

No one has mentioned line array (open baffle or not) speakers. I have only read about them, but I wonder if they might address the OP's call for "clarity" or "accuracy" or whatever magic word equates to what he wants.

 

I disagree with the comment about room interactions.  Most planar speakers are dipole and actually are designed for room interactions.  You send an identical  sound wave into a wall or corner and it is irrelevant if that sound wave was generated from a planar or cone speaker.  I agree completely with the comments about uniformity and ease of presentation, imaging.  I also agree with enveloping sound stage without being ever being harsh and yes they need power and dBels for all that to happen.  I've had visitors happily enveloped at SPL of 90 - 95 dB and never look at me like - what the hell.  I didn't hear QUICK mentioned and especially in the mid bass there is nothing like them.  The couch, chair and floor will vibrate -  musically and instantly.  Just don't expect anything to shake and rumble even with larger planars.  But shake and rumble generally ain't music anyway!!

@hilde45

No one has mentioned line array (open baffle or not) speakers. I have only read about them, but I wonder if they might address the OP’s call for "clarity" or "accuracy" or whatever magic word equates to what he wants.

speaking of line arrays, you should try a set of smaller maggies, quite affordable... and something definitely worth your experiencing - they are superb in what they do

"accuracy" in our hobby, of course, has no meaningful reference, so it is actually totally subjective ... as is the manufactured notion of stereo 'imaging', which, while very appealing when presented well in a good system, is also artificial... line arrays supposedly do the imaging thing less well, compared to more point-source style transducers

My experience has been, there is generally less interaction between The Room (side wall and vertical especially) and The Speaker, with regard to Plannar vs Cone. Plannars having fewer reflection interactions, Cones having more.

There is however,  a marked difference in the interaction within The Room when comparing Large Planars and Small Planars, in the same Room.

The size of The Speaker should be appropriate for the size of The Room... 

 

the most realistic and accurate sound i've ever heard was at definitive hifi in seattle, circa 1982 [about 40 years ago], a pair of maggie tympani IIIs were dominating one end of an acoustically treated room, on the other end were two [dorm room] refrigerator-sized monoblock class A amps that doubled as room heaters. i was sweating in there but the sound [from a direct-disc cathedral pipe organ {Bach} recording] was utterly enveloping with a "you are THERE!" feeling. the surface noise of the record floated in a little cloud a few feet in front of the speakers. being that i was not rich, i could not afford them but i did get the smallest ones they sold and those are in my collection today. in smaller rooms they [smg/mmg] did a lot of the "you are there" trick. 

The smaller planar diaphragm has less mass to contend with. Also, since planars behave as an imperfect line-source in practicality, the larger panel will have a  greater total of interference filtering. I haven’t compared measurements of say, the Magnepan LRS and 1.7i, but I would bet the former gets a little closer to textbook ideals. However, the average listener will probably perceive the larger of two panels to sound more life-like, all else being equal. 

what @jjss49 said!

FWIW, I own Soundlabs and previously owned Quads, heard a million Maggies in many systems. 

Small planar = no bass. That's why so many have tried cone woofer hybrids, 

I own M545 Sound Labs and with Bass focus, it has plenty of bass. I am not a bass freak and I don't listen to rock. I am thinking about moving to a bigger room. The question is Quad 2912 or bigger Sound Lab?

Hi @chungjh  

I am thinking about moving to a bigger room. The question is Quad 2912 or bigger Sound Lab?

That (obviously) begs the question: how big a room?

Since you asked for an opinion, mine is to go with the next model up (745) in the SL lineup. It will definitely fill the room up and if you listen to orchestral music, it will definitely offer a more plausible simulation of a full orchestra. 

I like what I've heard of the Quad, but IMO it's no match...

maggie also sells outboard bass panels too now, for users who feel their main maggie pair is still lacking in that department ... so with these, no need to go with coned sub, which can present the sometimes difficult integration issues

The next room size is 16x20x8. Someone near me tried the Maggie bass panels. He sold them. They just didn't do the job.

The next room size is 16x20x8. Someone near me tried the Maggie bass panels. He sold them. They just didn’t do the job.

quite possible that ’someone’ probably didn’t get them to work right... just sayin... 🤷‍♂️

chungjh, my understanding is that Music Direct will stop distribution of Quad ESL’s. I don’t know if they will drop Quad all together. Just realize that if you purchase the 2912’s or any Quad electrostatic speaker, that the panels will eventually need replacing and if you have a technician do it, then you’ll have to ship the entire speaker. The 2912’s are about 100 pounds each.

As far as AIG and their future production of Quad panels and Quad speakers, I am uninformed but I believe that someone will build the panels since all Quad ESL owners are in the same boat and will need to replace panels for their 63’s, 898’s, 2905’s and 2912’s. The 57’s have a different circuit board/panel design from the others.

If anyone finds out who the new USA distributor for Quad speakers will be, please share that in a post. Us Quad owners are somewhat at their mercy.

The next room size is 16x20x8

I have Magnepan .7s in a larger room than that and the bass is plentiful for my needs/taste. They don’t extend below 45Hz or so but still deeper than most bookshelf-type speakers and even some towers. This is the only Magnepan I’ve heard that can actually produce midbass “punch.”  I suspect it’s because it has a larger bass panel than the smallest Maggies yet is still a 2-way design. I once owned 1.7is and they had almost no dynamics in the midbass.  

I have been enchanted with Quads… old and new. My friend and dealer added the line about 15 years ago. I loved them, stopped buy several times, considered buying them… but didn’t. In fact everyone loved them… he carried them for years… and never sold a single pair… not one. I was shocked to hear this a few days ago when we were chatting.

@helomech: If you want to hear a Maggie with midbass punch, try to find a pair of the 3-panel Tympani models. Harry Pearson mated the two bass panels from a Tympani with the m/t panels from the Infinity IRS to create his own "super speaker".

The best midbass I've ever heard was that produced by my pair of Tympani T-IVa. But the Tympani bass panels need:

1- To be braced. Mye makes a stand for the Tympani. One guy on the Planar Speaker Asylum runs a plank of wood from his Tympani panels to the wall behind them!

2- To be placed at least 5' from the wall behind them. However, they may be placed right up against the side walls, which has the added benefit of eliminating the front-to-back dipole cancellation on the sides of the panels against the walls. Free bass!

3- A LOT of power, the more the better. 

A note to planar lovers, whether of the magnetic-planar variety (Magnepan, Eminent Technology), ESL, or ribbon: The Tympani bass panel is a GREAT sub for your speaker.

chungjh, yes, Music Direct and MOFI are the same company.

No one here has mentioned Acoustats. Anyone own these and if so, what are your thoughts?

@erik_squires 

You say in general panels are as flat as cones.

F'rinstance Martin Logan CLXs are +-3dB from 56 to 23000 Hz.  How much flatter would you like?

They sure sound good as well.  I have used panels for around 40 years now.  I don't miss the last octave, yes and octave from 55Hz to 27.5Hz, although bottom B on a Steinway Model D (the lowest note in music) is 30.87Hz.  For those that do, get subwoofers.

@clearthinker

 

You say in general panels are as flat as cones.

Well actually I made the opposite claim.

F’rinstance Martin Logan CLXs are +-3dB from 56 to 23000 Hz. How much flatter would you like?

Super poor example. I can’t find published measurements, and you are literally cherry picking a single $25,000 multi-way planar speaker. Trying to refute my claim of "general" with a very specific and unusual planar isn’t really a good way to get to clear thinking my friend.   You also seem to have completely ignored my opening caveats:

It varies a great deal, but usually...

So I can be 100% correct and the CLX may still be unusually good performers. There's no conflict in these two statements, but I would love to see a frequency response chart just for giggles.

Well, I don’t know about all that, but I DO know that IN MY SHOP, we listened to every box, electrostat, etc. speaker available and the only ones that sounded like the instruments we were playing live were the Maggies.

Yes, we played trumpet solo and then switched back and forth between trumpet solo recordings, same with clarinet, guitar (all versions) and (unfortunately due to size of the shop) electric piano, and drums. When we switched back and forth, we could not tell the difference (behind a scrim, so no visuals here) between the live instruments and the Maggies (driven by Audio Research gear).

Solved the question for me, BUT, many of my customers’ ROOMS were not amenable to Maggies, so they sounded not good IN THEIR ROOMS.

SO, yes, they give the most realistic sound stage, etc., and NO, they do not shake the windows with over-driven distorted bass, which many crave, for a few minutes, anyway unless you are 17. Electrostats like Quads and KLH and RTR’s give listening fatigue after a very short time.

Here is the answer: Have your dealer set up the Maggies IN YOUR ROOM. IF you have super-high-quality hardware and source information, you will never go back. If this is not for you, buy what you like.

By the way, I have always wondered where all those box manufacturers got the BRILLIANT idea to make their speakers tall "all of a sudden". Funny how that happened, huh?

Cheers!

Disclosure: Speaker designer (planars too) and Manufacturer.

The OP's question is: Do larger planar speakers produce more accurate sound?

The challenge of answering the question is that "accurate sound" is not well defined. If he is asking about accuracy of the waveform produced by a planar transducer compared to the input signal, within the frequencies and amplitude the transducers are designed for and everything else being equal the answer is no. An argument can easily be made that smaller planar traducers are more "accurate". 

Most of what is being discussed here by others is about dispersion patterns, room interaction and other design choices. Furthermore, "planar" is not defined here. There are several types of planars. 

 

@arion I apologize for the lack of clarity. By "accurate", I meant realism. Sor the sake of simplicity, let's focus on electrostatics.  To generate the same SPL with smaller radiating surface, it would mean greater excursion of the membrane than with larger radiating surface. I would think that the requirement of greater excursion would mean loss of tension (over many years) in the membrane and less resolution. Unless membranes require large excursion to produce higher resolution.