Dynamic sound vs Planar Magnetic sound
Jan 29, 2014 at 4:38 AM Post #47 of 124
From what I've read so far, dynamic and planar magnetic are two different technologies.
Went through the article on innerfidelity by Tyll.
 
My observations so far:
-- Planars seem to be the 'better' design. Better from a purely electrical and sonic standpoint.
-- They're heavy and may be uncomfortable.
-- They produce a planar wavefront. The same is done by the HD800.
-- Planars seem to struggle in the high frequency area.
 
Questions:
-- Why aren't they popular? Disruptive Technology? Price?
-- Why can't other dynamic headphones be designed to produce a better wavefront? The HD800 seems like it can.
-- Are they 'superior' or just 'different' ?
 
Jan 29, 2014 at 10:59 AM Post #48 of 124
Great Summary Proton -
 
As I suggested earlier, the weight, price, and relative 'crudeness' of current planars versus dynamics (which are literally disposable in some applications like airplanes) suggests to me that they suffer under- or a lack of development by businesses. Businesses, with large sunk costs in dynamic technology, do not have an incentive to innovate in planars. But some of the new companies springing up do - because they are able to get extremely good sound at a cost that can compete with the best that dynamics offer.
 
I suppose we'll know the technology is mature when it can be found in a $25 dollar set of cans sold at Wal Mart.
 
I suppose Planars can't be considered "better" outright - otherwise dynamics would be obsolete already and many companies would be making the transition (cough, Sennheiser). So the "compromises" that are forced by going to a planar design must still create economic and technical inefficiencies.
 
Jan 29, 2014 at 12:16 PM Post #49 of 124
I'd imagine the array of magnets and the diaphragm to be more expensive to manufacture, hence higher costs even with maturity. That said, the Fostex set wasn't all that expensive. Did it use a smaller array? Different arrangement?
 
Also, there seems to be a steeper tradeoff with respect to weight, distortion, and sensitivity, other factors too probably.
 
 
I don't know much at all about headphone operating principles or even electromagnetics, but given a certain magnet I would assume that having the diaphragm closer to it would result in higher sensitivity because the magnetic field strength is higher there, right? But closer up, a given displacement will be a greater shift from the neutral position, so nonlinearities would go up? Also, if you use magnets on only one side rather than both, that would seem to be a good idea for weight and cost reduction, but I can't imagine that being more linear without some compensation elsewhere.
 
 
Note Fostex TR50-RP relative performance (even when modded; particularly note increased distortion for equivalent volume after people mod them because I'm guessing the damping eats up the sound output and you need more excursion for a given volume) and cost. Also note that HE-400, which has relatively high sensitivity, has midrange weirdness and higher distortion. For magnets only on one side there is the JPS Labs Abyss, which also has higher distortion despite its cost. HE-4 is also supposed to have magnets only on one side, but I don't see measurements for that. Upcoming HiFiMAN HE-400i and HE-560 are lighter than previous models and also only have magnets on one side. Supposedly sound is improved over the older HE-400 and HE-500 models, but we shall see.
 
Jan 29, 2014 at 6:17 PM Post #50 of 124
I guess more research and development has gone into dynamic drivers over the years. That, as well as (presumably) cheaper manufacturing costs. These might be a few of the reasons why there are many high-end dynamic cans.
 
Jan 29, 2014 at 6:59 PM Post #51 of 124
Neodymium magnets at tolerable cost is really the change enabling new interest in Orthos
 
Jan 29, 2014 at 7:57 PM Post #52 of 124
JCX - That's an interesting theory.
 
White Lotus - That would be my best guess. On the other hand, we are having a real headphone renaissance these days, as head-fi has been identified as a good niche for a lot of companies. Must be the success of Smart Phones or something. I would point out that a lot of flagships have what, 10 year runs? The HD 600/650 have been around forever. Seems only recently Sennheiser felt the pressure to really do something new and awesome.
 
MikeAJ - while I don't agree with "midrange weirdness and distortion" in the HE-400 (which I think have a beautiful midrange at times), the distortion has been measured. I would point out that said distortion is recorded at pretty high SPLs, so we don't always know how speakers are behaving at less ear-damaging volumes.
 
Double-ended planars are supposed to do better with respect to distortion than single ended, as two magnets provide twice the control of one. But they also would impact the diffusion of sound, I would think, so single ended probably has even better intimacy in exchange for more distortion and less linearity at higher SPLs.
 
I have to admit, the HE-400i seem to me, at least initially, to be a weight / cost / performance cut at a higher price - the opposite of what a consumer wants. But I guess the Magnepan speakers are single-ended also, so, you don't know til you can hear.
 
Jan 29, 2014 at 8:16 PM Post #53 of 124
Yeah, it's probably significantly lower at say 80 or 70 dB SPL. And I suppose I meant "relative weirdness" or at least some evidence of some performance issues, not really a comment about the headphone itself but rather on what seems to be the state of the technology.
 
On the other hand, when people talk 1W into 50 ohms kind of amps for HE-400... actually, it's probably best not to think too much about that.
 
Jan 31, 2014 at 11:04 AM Post #54 of 124
Over at InnerFidelity, the LCD planars generally keep distortion at or below say, 1%. Hifiman's other planars are generally very good also, at around 1%. Very clean, very well behaved.
 
The Abyss, despite its high price, is actually a little distort-ty (between 1-10% in places).
 
The HE-400 looks the worse out of the group, but there are lots of observations to make. For one, the issues are mainly in the 200hz - 2.5 khz range, which are critical frequencies, but that is a narrow band. It is also measured with the pleathers, not the velours or modded pleathers (though I am not sure if the distortion would be any different. Finally, I always thought the general rule was that you wanted to see results less that 10% THD. Judging by all the peaks you can see, I would guess that average distortion is probably closer to 1%.
 
Then there is the issue of deciding what is "audible" versus what is just "measurable". In any case, I think you are right that planars may show their worst performances in the midrange/treble areas - Large drivers trying to vibrate quickly. When I look at the very best dynamics, however, they always seem to post the worst THD values at the bass and treble extremes - yet they are somewhat linear typically. The look like they are optimized for midrange performance and suffer at the extremes. the relative opposite of what planars seem to do well (low THD bass and treble, distortion in the midrange).
 
Feb 1, 2014 at 7:19 AM Post #55 of 124
I think it's the larger size of the planar driver - being very extremely effective at creating pressure waves of lower frequency.  The fact that transient response is faster than any dynamic means they do not have a problem with frequency extension.  I think the magnetic bars might pose as a kind of attenuator to the treble energy...although being more extended in response than dynamics the treble is of lower amplitude than the rest of the frequency response.  Which I believe, incidentally is a good thing for headphones as the attenuation of treble matches well known headphone HRTF models.
 
To say that a planar is rolled of at the treble would not make sense, as a true roll-off would blunt transients.  Planars in the speaker world are renowned for making good tweeters and midrange drivers and in fact, are poor bass drivers.
 
Actually, the more I think about it...I think it is just the tuning of planars to sound in a manner to exhibit its strengths.  Overall...the mids on all my planars exhibit the most realistic voices I've heard in headphones.  If you were to brighten the Planars to HD800 levels, sure the goodness of vocals is still there, but the qualities are slightly diminished by being masked by treble.
 
Feb 12, 2014 at 8:40 AM Post #56 of 124
JCX - That's an interesting theory.

White Lotus - That would be my best guess. On the other hand, we are having a real headphone renaissance these days, as head-fi has been identified as a good niche for a lot of companies. Must be the success of Smart Phones or something. I would point out that a lot of flagships have what, 10 year runs? The HD 600/650 have been around forever. Seems only recently Sennheiser felt the pressure to really do something new and awesome.

MikeAJ - while I don't agree with "midrange weirdness and distortion" in the HE-400 (which I think have a beautiful midrange at times), the distortion has been measured. I would point out that said distortion is recorded at pretty high SPLs, so we don't always know how speakers are behaving at less ear-damaging volumes.

Double-ended planars are supposed to do better with respect to distortion than single ended, as two magnets provide twice the control of one. But they also would impact the diffusion of sound, I would think, so single ended probably has even better intimacy in exchange for more distortion and less linearity at higher SPLs.

I have to admit, the HE-400i seem to me, at least initially, to be a weight / cost / performance cut at a higher price - the opposite of what a consumer wants. But I guess the Magnepan speakers are single-ended also, so, you don't know til you can hear.


Could you tell more details about HE400i?
 
Feb 12, 2014 at 10:08 AM Post #57 of 124
Could you tell more details about HE400i?

There are a few places online to read about the 400i, and a separate thread already devoted to rumors / speculation.
 
They should be released next month, so we'll know lots by that time. I am most definitely going to consider them if they are a big improvement. Key issues with the HE-400 have been comfort, weight, and ergonomics. But sound quality has been noted for being awesome (especially with minor tweaks). I am expecting a more balanced sound signature with more speed and a more comfortable weight and fit. But I am hoping that the brightness / aggressiveness will be preserved as it serves a lot of genres well.
 
Feb 14, 2014 at 11:01 PM Post #58 of 124
  My Mad Dogs have more precision in the sound, especially in the sub-mid bass region. This is clear on acoustics tracks. 
 
The problem I hear is present in piano music. It loses a lot of the dynamics that the artist intended (it's obvious because some scores have accents to them, and the Mad Dog do not portray them well). Everything seems "flattened" out to the same dynamic level. At first, I thought this was because the Mad Dogs were so neutral, and they are, not particularly emphasizing any particular frequency except the bass (to compensate for the vibrations that enter our bodies). But even with this in consideration, I feel like I'm hearing a wall of sound. I need to hear another planar magnetic can to confirm if this is just that kind of signature. MIdrange has less presence in my Mad Dogs for the most part, with a more artificial timbre. 

 
Yes you need to hear other planars.  I've gone through the how what and why of the stock T50RP in the original mod thread and will not repeat it again.  Suffice to say any can that is not of a pure open back design (semi-closed/semi-open is not an open back) will inevitably restrict maximum air pressure and precision of air pressure variation (some part of the frequency response) as induced by the electrical stimuli.  Take a guess at how that involves the definition of dynamics.  Bass needs a lot of air to be moved...and so to does piano notes....least is treble.  There is only so far you can go with the soft plastic of the T50RP cups.
 
This is just plain and simple physics 101.
 
  Oh yes it's definitely fast. The problem here has nothing to do with fastness. And no this applies to every song/ piece I've listened to out of the Mad Dogs. I've been trying to find comments about this 'wall of sound'. I've read it once somewhere but can't find that specific comment. Instead I've found: 
 
"As Brooko said, I didn't say inferior.

The "deal" with any planar radiator (ESP, electret, planar-magnetic/orthodynamic, etc) is that they put out a very uniform "wall" of sound, compared to the conical pattern that will come out of a dynamic cone (which is what you'll find in every Grado ever made). This is a very different presentation on it's own, even if they had the exact same frequency response (which they do not), because of how the sound-wave will interact with your outer and inner ear. So just like how an Ultrasone with S-LOGIC will not image or position audio in the same way as any conventional headphone, neither will any planar radiator. Same thing with speakers - there are plenty of great-sounding speakers that use multiple drivers in various alignments, and there are also a number of planar/dipole models that are also great-sounding. But they produce a very different sonic image because of the difference in how they put sound out.

So not only should you expect to see a large difference in tonal balance (in that, nothing has the same PRaT, tonal balance, etc that a Grado does), but the difference in radiation will also change and influence the sound very heavily. I will tell you that flat-out, if you think your Grado headphones are the best sounding thing since sliced bread, nothing else will get you that same experience except another Grado. They're very unique. I say this to hopefully prevent a lot of dragon chasing - don't waste your time with other manufacturers trying to get "a better sounding Grado" - just get a better Grado. If there's *major* issues you have with Grado headphones (e.g. you hate their tonal balance), don't waste your time buying more expensive Grado models - try something else.

It all ultimately comes down to preference - do you like chocolate or vanilla or perhaps Neapolitan?"
 
 
 
 
"The "wall-of-sound" effect is because LCD2s are heavily damped, unfortunately that damping scheme is also what makes it sound like an Audeze headphone. I can make my HE400s sound quite LCD2-like with similar driver-back damping with foam and felt, without the properly tuned bass response / smooth mids ofc, but as a proof of concept." 
 
 
Wish I had another planar magnetic to know for sure. I've only ever listened to dynamic drive headphones (lots of them) and they don't have this kind of sound. 

 
Right...now I understand where this 'wall' of sound criticism for the LCD2 originated from...perpetuated by people who have no clue - and suffering from placebo.  They also have never been amongst the musicians in a performance.  Instead of mucking around with damping schemes, I suggest to just use an equaliser.  Any damping scheme that restricts air pressure in the powerful midrange and bass frequencies are not used in headphones...their job is to control lower and upper treble - it's just a fabric over the speaker...the treble - which involves minimal air pressure.
 
It is true with my Grado HF2...they're fast in the uppermids to treble...much faster than the K701 and HD650.  Very quick in the midbass as well.
 
  No not at all. The HD650 does sound heavy, mainly because of its midbass. I had the same impression with the M50s as well. The Mad Dog has a very neutral midbass... about the same amount as my HD598 actually. 
 
Maybe one day when I get the chance, I'll be able to compare it with a HE-400 or another planar magnetic. 
 
Oh and I didn't "upgrade" from anything. I own the HD598 currently, though I've auditioned numerous cans in the price range and above. No dynamic headphones sound quite like the Mad Dogs. My main interest currently with the Mad Dogs isn't really its "wall of sound" but rather the lack of dynamics. Everything feels dampened, and although this doesn't affect most genres of music, it does affect my piano music heavily. A friend came over to audition my two cans and he agreed that the Mad Dogs just can't compete with the HD598 in classical music (well excluding organ). But he loved the Mad Dogs for darker ambient music. 

 
I think the preference here is merely for the 'open' back characteristic of the HD598 over anything. 
 
HD650, heavy?  in comparison to what?  Your HD598? some small bookshelf speaker? large 4 way active reference speakers with 15 inch bass drivers?  live instruments?  A real drumkit? other headphones?  WHAT?
 
  From what I've read so far, dynamic and planar magnetic are two different technologies.
Went through the article on innerfidelity by Tyll.
 
My observations so far:
-- Planars seem to be the 'better' design. Better from a purely electrical and sonic standpoint.
-- They're heavy and may be uncomfortable.
-- They produce a planar wavefront. The same is done by the HD800.
-- Planars seem to struggle in the high frequency area.
 
Questions:
-- Why aren't they popular? Disruptive Technology? Price?
-- Why can't other dynamic headphones be designed to produce a better wavefront? The HD800 seems like it can.
-- Are they 'superior' or just 'different' ?

 
Bingo!
 
we have a winner.
 

Quote:
 
When one passes a signal through a filter (or a headphone), the "processed" signal will not come out immediately. The signal will come out a bit later because hardware does not respond instantaneously to an stimulus. A bunch of junk will come out first depending on how "fast" the hardware is, and how it reacts to certain frequency stimulus. This junk that comes out first is usually referred to as a transient.
 
AFAIK, the impulse response represents the linear transient behavior of filter (or a headphone). I guess the less junk before and after the main peak of a headphone's impulse response, the "faster" the headphone.

 
 
I have never ever been able to correlate the impulse response graph to anything I actually hear on headphones.  Least of all transient attack.
 

Lesson I learned:  I need to read a thread from the start before wading in to a debate...not just the last page.  IMO, Planars have superceded dynamics by a good margin in the high end market, the only place that should be left for dynamics is portable, light, rugged, convenient headphones.
 
Feb 15, 2014 at 12:18 AM Post #59 of 124
^ good thing you added "IMO" coz that's all it is. planars haven't superseded high-end dynamic headphones or speakers.
 

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