Wednesday, March 26, 2008

The Myth of The Ribbon Microphone Exposed! Part Two Update


Now dimly aware that his party with faceless apes must end, The Joker
sets out on his checkered journey toward modern civilization.



Editor's Note: This is an updated version of a controversial post that I wrote in 2006. It is explicit in that it discusses a lot of the oft-repeated nonsense about ribbon microphones that we still hear and read about. Some people got it, and some just didn't. If you have followed the microphonium blog you might have noticed that we never directly criticize another manufacturer, nor do we take apart or attempt to show the workings of any in-production microphone other than our own. To be on the safe side, we also never compare our measurements of a competitor's microphone with their published measurements.

Here is a link to a gearslutz discussion with criticism about this post.

We do this to be polite

A lot has happened here at Crowley and Tripp Microphones since Part One of The Myth of the Ribbon Microphone was published. We invented a new material which we call Roswellite tm that seems to be changing, in a very fundamental way, our thoughts about the ribbon microphone, how it should be designed, what we should expect from it, and the new things we can do. Other important changes have been related to vocal recordings, which ribbons are being called upon to do more and more, and also field recordings, where ribbon microphones like Naked Eye Roswellite, now tough enough to finally go outside, are being used.

So in looking over the original "Myths" I thought it was time to interject a few new comments that reflect the state of the art, which has changed. I will also make a few comments about parts of the original "Myths" that brought in some very funny and a couple of quite angry emails. The original is in blue, and my new comments are in red.

Enjoy!


Before objective knowledge there was dancing, fire, and superstition.
Some people were offended by this comment, which has multiple meanings. I like it.

"The Knowledge" of a London cabbie consists of a complete mental map and image of the the city roads and byways and those with The Knowledge are then qualified to transport via black cab any passenger to any location within London.

The Knowledge of Ribbon Microphones - A Codex inscribed herein for posterity - consists of the true facts and explanations about the mysterious and sometimes ancient mythology of the revered and sometimes reviled ribbon microphone.

The Myths are many and the tales told are handed down over the generations of recording aficionados and repeated almost as prayers in the scripture of the ubiquitous message boards, where no false word is ever erased, and lore is mixed with fact, fiction, lies, myths, heresy, pure falsities, and half-truths.

That paragraph pissed a few people off and delighted some. We have a tendency to appeal to so-called "early adopters" because what we do is inherently disruptive and tries to produce change. This appeals to those who "believe in innovation", but not others who "believe in tradition". It's not about beliefs though.

And then there is the phenomenon of repetition, whereby the truth is manufactured, where errors are repeated, often over and over, until they become accepted facts, despite the lack of supporting evidence. Like parrots, the falsehood is recanted, passed down through generations, and finally accepted without question.

Here are a few myths to get us started:

Vintage Myths - those myths based on lore, history, and New Old Stock

Myth: "Nothing sounds like/as good/mellow like an old RCA 44, 77, (insert an old mic here)"
Fact: These mics were good and produced excellent sound, but have low output and relatively high noise levels, and are highly variable. Most of the vintage ribbon mics have a steep roll off beginning at 10 KC. If you can put up with unpredictable performance, they may be for you. I have three RCA 77DXs here in the lab at the moment. You can bet they sound good, but different.

I sold one of my 77DXs recently.

Myth: "Such and such has New Old Stock ribbon material (magnets/grille cloth/blueprints/uncle/DNA) which is the best"
Fact: Old ribbon material is likely to be inferior to modern materials. Aluminum oxidizes slowly but corrosion can produce pinholes, while precipitation (age/heat) hardening causes embrittlement, and fracture. Present day aluminum is produced in precise thickness and with better purity than was available even 20 years ago. This is due to demand for thin foils in other parts of the electronics industry, such as capacitors.

Naturally since this was writtten before Roswellite, the emphasis was on aluminum.

The Saggy Baggy Ribbon Myths - Things may droop over time, also with ribbons?

Myth: "Ribbon mics should be stored vertically".
Fact: No. The weight of a typical "large ribbon" is around 0.0018 grams, and a thin ribbon is about 1/4 that. If that is enough to cause sagging, then something is very wrong. Ribbon microphones of any vintage can be used and stored in any position.

Nothing has changed, except I learned that one somewhat "in production" microphone (remember our rule) seems to have such a fragile ribbon that it does indeed sag and blow out often. Also, there are a number of new ribbon mics that are being shipped with saggy ribbons either from the factory or from shipping damage, or some other reason. Check out Lynn Fuston's 3Daudioinc.com website for pictures.

Myth: "Just closing the case will blow the ribbon"
Fact: This is quite doubtful. Once again, if the air pressure is enough to damage the ribbon then most of ribbon microphones out there today are already blown. Several manufacturers including us supply ribbon microphones in horizontal cases with top lids. I think you would have to try to slam it very hard, over and over, to show any change to the ribbon tension.

With that one un-named exception, mentioned above.

Myth: "Crowley and Tripp uses a vertical storage box to prevent ribbon sagging."
Fact: We did this so you can see it and because we thought it looked better and was more convenient, and that it might cause the user to grab it from the mic locker more often rather than laying flat in the dark recesses of the cabinet. You can lay the box down on its side, turn it upside down - it doesn't matter at all because gravity has only the most minute influence on the ribbon.

Myth: "All ribbon microphones are fragile"
Fact: Modern ribbon microphones are not at all fragile.

There are various degrees of "fragility". Roswellite ribbon mics can stand up to windblast and repeated phantom power misapplication, and are far less "fragile" than the strongest modern rugged aluminum ribbons.

Myth: "Move the ribbon mic slowly"
Fact: Nonsense. I saw an intern walking across the studio holding the microphone like it was a lit candle. This was very amusing.

I got more email on this one and all kinds of similar funny stories.

Myth: "Loud sounds will shatter the ribbon"
Fact: Loud? Not loud like loud music loud, at least. No. Detonation of high explosives, maybe. Do not try this.

Phantastic Phantom Myths - Images of smoke, fire and destruction.

Myth: "Phantom power will destroy a ribbon microphone"
Fact: Not usually. Phantom power correctly applied does so evenly, so there is no net force on the ribbon.

Not ever with Roswellite.

Myth "Phantom power will not destroy a ribbon microphone"
Fact: Usually. Phantom power can stretch an aluminum foil ribbon. Any signal that is applied unevenly, such as 1. through a patchbay which is a bad idea anyway, or 2. by hot swapping cables, WILL boink the aluminum foil ribbon in passive ribbon mics.

Phantom power will not ever destroy a Roswellite ribbon.

Myth: "Phantom power will demagnetize the magnets"
Fact: I had to include this one since it was so interesting, and impossible.

Oft-Repeated Mythicisms - merely annoying, or insidiously harmful?

Myth" "Ribbon mics are dark sounding"
Fact: Some are, more modern ones are less so, and a couple are neutral to bright sounding. You choose.

Figure Eight Type Myths - fundamental things about sound in general actually...

Myth: "The back of a ribbon mic is usually brighter than the front"
Fact: This is definitely not so. Most good quality ribbon mics, ours included, are perfectly symmetric in response. The only difference from front to back, of course, is the phase. We think it's slightly embarassing at times to have to explain why this sounds different to people wearing headphones. No offense! Avoid uncomfortable social gaffes and use your phase reverse switch.

I still read this erroneous myth about ribbons usually being brighter on the back on certain sites that are not up to date, and in discussion forums. The tone of a symmetrical ribbon mic is the same, front or back. That includes most ribbon microphones.

Exceptions: Naked Eye is intentionally asymmetrical in response with a 3dB average 8-12 KC presence rise off the back, with no dips. (recall the embarassing phase cancellation phenomenon causes some people to misunderstand). The so-called "offset ribbon designs" are unintentionally different in tone color from front to back, I suppose because the distance from the mic body and screen to the ribbon varies from side to side. Intentional or not, it can be useful. The RCA 77DX is rather asymmetrical even in the figure eight position. This is a problem inherent in the 77C, 77D and 77DX because the local field around the ribbon motor isn't quite symmetrical to begin with, which is intentional because it is a multipattern mic.

I see this repeated still today.

Myth: "Ribbon mics have low output"
Fact: Modern ribbon mics have a HIGHER output than most stage dynamics. Remember that a condenser capsule has NO output and depends on the internal active electronics which are essentially a high gain voltage amplifier.

Myth: "You need a preamp with tons of gain"
Fact: No. Not only is the answer "no" but you can use your preamp wide open and unrestricted because ribbon microphones have extremely low self noise.


4 comments:

Gordon said...

Phenomenal, I'll be directing more than a few people to this myth-busting post. Thanks!!

Anonymous said...

HAR HAR HAR YOU SHOOK THEM UP LOOK AT THE WINING ON GEARSLUTZ!!!!

justin said...

can someone please tell me who did that painting of the joker and apes on this post. I love it?
email me: marchese_justin@yahoo.com

Bob Crowley said...

Artist unknown. Painting found at Brimfield antique show for $18 which was a bargain in my view. Isn't it great?