Are thin film diaphragms better?
Wow.
Ready for liftoff? 3...2...1... Here we go!
Short Answer: Coming from the perpetuator of the company that pioneered lower mass large diaphragms back in 1984, my answer may surprise some folks out there...
Sometimes.
But first: to ask a question like this is not like asking "Apples or Oranges," rather more like "Red Delicious or Granny Smith?" For there is no "better" in my mind, only different flavors, or colors on the palette... Strat or Les Paul? Martin or Taylor? Countach or Testarossa? Hayek or Klum?
Actually, the question itself has very little meaning, because the diaphragm is only one part of a complex and (sometimes) finely tuned system. I've built capsules with thin (Mylar) films that I would readily put up against ANY microphone original or modified, yet I'm still wrangling with getting 0.4 micron film to sound completely stunning. Many times those mics would win, sometimes they would lose- Why? Every application is different. Every set of ears is different. I've worked on mics that I thought were deficient in some particular area, yet it was exactly the deficiency needed to compensate some vocalist's overemphasis in that area, and vice-versa and on and on. Anybody tasted the difference between a pie baked with Red Delicious and one baked with Granny Smith? How about applesauce with those same two? Different applications.
As is readily apparent by now,(to wit, the larger part of the Sino-based dreck swamping the market) there is a lot more to making a microphone sound really
Good (musical, sexy, etc....) than just machining some parts and sticking them together. It's entirely all too easy to assemble a capsule with
thinner diaphragms that really doesn't please anyone. So, the passing of judgment on all thin film mics based on hearing one or two is truly premature.
As for the longevity/reliability issue, I've said this before in this forum - in all the mics I've had a chance to examine, I've never seen a thin diaphragm fail due to its inherent thinness. Physical violence (Overeager tech, Drummer, Gravity) or adhesive failure (usually due to physical violence) are the cause of 99% of diaphragm failures. Mylar(r) is a remarkably tough film, and as long as there's no mayhem inflicted upon it, the film itself holds up. Period. There are 1.5 micron capsules in rental situations that are now more than 22 years old and still going strong. 'Nuf said.
Transient response may or may not be the strictly correct term to use for the perceivable increase in definition and transparency (for example the difference between hearing individual raindrops and hearing basically white noise,) but it's the most likely culprit in my mind. Regardless of the fact that the air cushion behind the diaphragm is a major contributor to high frequency response in a pressure gradient capsule, there is the issue of
inertia. One can argue that, with the proper damping, the inertia of a more massive diaphragm becomes irrelevant; I would argue that with lower mass and lower inertia, not only can higher sensitivity to the more delicate pressure waves result, but less damping is necessary as well. I will leave it to the reader to draw their own conclusions about whether less damping is desirable, though I will point out that a rough analog can be drawn to negative feedback in an electrical circuit.
So why, you ask, did I say sometimes? Well, I've tried to use thin diaphragm mics on inferior instruments -- I got inferior results. Too much detail. Too much clarity. Too much inferior instrument. An SM57 turned out to be the deficiency that made up for the deficiency in the instrument. Of course this is the extreme, but serves to illustrate the other end of a
Broad spectrum over which many different microphones apply.
On another hand, the most consistent response I've gotten from users has been along the lines of "the artist is going nuts, they've never heard themselves like this before" and as a result the performance they delivered was more inspired. On the bottom line, I think that's what recording music is all about; listen to any early Motown record - I hardly think an argument could be made for sonic superiority on "Tears of a Clown" but the performances (and the songwriting/arranging) made it a classic.
Jeez, if only they'd had thin diaphragms...
(And yes, CK12's can usually be rebuilt to stock specs even after a mod - it depends.)
Best,
Tony Merrill
Stephen Paul Audio
