How Planar Magnetic Headphones Work Page 3
The Disadvantages of Planar Magnetic Headphones
Damping --- With electostatic drivers, the charge carrying stators on either side of the diaphragm can be very thin and sonically transparent. Planar magnetic driver diaphragms are surrounded on either side by relatively large structures. The magnets are fairly large, and the opposing force they exert on each other is significant, so sturdy metal structures hold the magnets in place. There is a significant amount of trapped air in volumes of various sizes that must be moved before sound is radiated out of the driver. The springiness and resonances that may exist in this trapped air volume can cause problems. Quite a bit of the design effort with planar magnetic headphones seems to be spent on getting just the right damping. The vintage Orthodynamic headphone scene is filled with various damping modifications done by enthusiasts.
(As a side note: I’ve asked for some help over in the Head-Fi Ortho thread from members who would be willing to ship me their modified headphones for measurement. I’ve been very pleased by the response, and you should start seeing measurements of these DIY modified planar magnetic headphones within a few weeks.)
Weight --- As really cool as neodymium magnets are, they’re still heavy. The weight and size of a planar magnetic headphone driver makes these headphones potentially uncomfortable.
The Sound of Planar Magnetic Headphones
There is no one particular sound to these headphones, of course, but there are a few common characteristics worth mentioning about the new cans from HiFiMAN and Audez’e (pronounced like odyssey). Headphones from both these makers have about the best bass response I’ve heard. It’s tight, linear, and beautifully textured. Tubas and plucked stand-up bass notes are fully recognizable and characteristic. One-note bass is a thing of the past with these cans; just extraordinary.
Treble response seems to be an issue with planar magnetic headphones likely due to an ongoing need to keep working on the damping issues. The HiFiMAN products tend toward the tizzy side, but I’m very happy to report that they seem to have been making worthwhile adjustments with the release of the various models (HE-4, HE-5, HE-5LE, and HE-6), and with the introduction of their soon-to-be-released can (the HE-500 that I’ve had the pleasure of listening to for the last 2 weeks) I think you’ll find that they’re very close to spot on.
The Audez’e LCD-2 has difficulties in the other direction in that many find them a bit too relaxed in the highs. I find this to be true as well, but need to remark that I tend to like a warm sounding can, and with extended listening I adjusted very well to the presentation of the LCD-2. They make a GREAT headphone for hip-hop and rock where bass slam is strongly desired, and the relaxed top-end permits lengthy listening to the often-harsh recordings of the genres.
Imaging is likewise very good on these headphones, but it seems to me the problems in the treble may be holding them back from the imaging that may one day be realized with headphones of this type. I encourage the makers to continue their quest for good treble, and therefore imaging, as I’m certain their efforts will be rewarded.
I’m simply amazed that two small companies can enter the high-end headphone world with a long ignored technology and produce what amounts to world-class sound from their efforts. Obviously, planar magnetic headphones are here to stay. I hope the big corporate makers are watching, and, more important, listening to these new headphones. I heartily applaud the efforts of Audez’e and HiFiMAN on the work they’ve done, and will heartily recommend both makers products in upcoming reviews.
Resources after the video.
A very well written introduction to the technology from planar magnetic speaker maker Wisdom Audio.
A great source for information on rare headphones including the Yamaha Orthodynamic line is Wikiphonia.
Home pages for planar magnetic headphone makers HiFiMAN and Audez’e.
Head-Fi threads on the Audez’e LCD-2, HiFiMAN HE-500, and the massive Orthodynamic Round-Up, a thread for vintage Orthos.