Thursday, December 28, 2006

Naked Eye Matched Pair Deal with Goodies!

This promotion ended on Feb 15,2007.We sold out!

We have a great deal for those who want a pair of Naked Eyes for use around the studio and in venues to record in stereo. Have you read the reviews? You should!

Here's what the deal consists of:

2 Matched Sequentially Numbered Naked Eye Ribbon Microphones
2 Low diffraction rotary mounts
1 two-piece Array Mast for use on a boom or in stereo array. This consists of two strong aluminum mast sections that screw together and holds two Naked Eyes.
2 wood storage cases
All US made
Other small but cool and/or useful goodies
Price $1495 - cash, paypal, Visa or Mastercard (no Amex)
No shipping charge anywhere in the US!
No matching charge (of course)
Order by calling the lab direct at 508 231 4515 during business hours EST.

As you probably know, Naked Eye has become a phenomenon and a best seller at the introductory price of $745 each. Get in on this deal because 2007 is coming!

The Myth of the Ribbon Microphone - Exposed! part one

"Faceless ancestors who dance about the fire of knowledge, their long shadows cast close behind them."

Be sure to read PART TWO, also. Link HERE

Before objective knowledge there was dancing, fire, and superstition.

"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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

January 10 2007 note

Aha! I see we have stimulated a little debate about sensitivity. This is good and an opportunity to spread some numbers around.

A modern ribbon mic might be represented by a Studio Vocalist which has its stated sensitivity as -50db. This is from the standard that uses a 1 Pascal SPL at the source where 1 Pa = 94 dB, which is a little bit loud, and by measuring the actual open circuit voltage measured right at the XLR connector. You can do this measurement yourself very easily with a good multimeter, and perhaps I will take pictures of the setup and write a how-to soon.

Anyway, compare these two:

Studio Vocalist -50 db which is equal to 3.1 mV/Pa
SM57 -56 db which is equal to 1.6 mV/Pa

The Studio Vocalist appears to be more efficient at converting sound energy into an electrical voltage. What does this mean as far as "knob" gain? perhaps just a little. Can you use an SM57 with your preamp? Let me know, because if you can then you should have plenty of gain for a modern ribbon mic. If not, please let me know that, too.

In all fairness I am comparing a figure eight patterned mic with a rather big aperture to a cardioid dynamic with perhaps a little bit smaller aperture, so the two may actually be closer than the numbers. Still, here is one example of a ribbon mic with an output higher than something that you may have already used, so use your own judgement.

Tuesday, December 26, 2006

MORE: "Matched Pair" of Ribbon Mics Ready to Ship

People always ask us about "matched pairs". Above you see a pair of Studio Vocalist Ribbon Microphones in the box ready to ship out to some distant location. Notice that each box is separated by foam and that the box is thick and heavy material. The last thing you want to worry about is if your mic is going to arrive in one piece. This type of packing makes it very unlikely that a mic will be damaged during transit. A cardboard box can be made very strong and consistent. Wood is strong too, but the natural grain of the wood box, which we supply gratis with most microphones, never matches perfectly and sometimes varies in color and even slightly in dimension.

But this post is about "matched pairs" of microphones. As a manufacturer of precision products, we wondered about the common "extra charge" some microphone makers levy for two mics of the same exact model. "No way!" we said. "They all should match". You can take any two (or four or more) of the same model of any Crowley and Tripp mics and they will already match in tone, frequency response, sensitivity, appearance and dimensions. Very closely. In most industries where precision affects performance, like in medical devices, parts are usually designed so they come out virtually the same each time, so wouldn't you think a mic could do that?

Imagine if a maker of replacement hips charged extra to patients who wanted their new hip implants to "match".

Now some people want "sequential, matched pairs" which means that the serial numbers are sequential. No problem, we can do that. Just ask. That's easy!

But what about the matching charge?

There isn't any. We don't think you should pay extra for buying two of our mics or be penalized because you need them to sound the same. We never add a "matching charge".

Sunday, December 24, 2006

Make Your Own Triode

Here is a film from Holland showing the making of a simple Deforest type triode vacuum tube capable of rectification and amplification. Notice the vintage Philips refrigerator in the background and the use of Philips lab. I visited Philips a while back and saw their facilities in Best and Eindhoven, Holland.

Here is the video!

Baking elements helps remove residual volatiles and also eliminates the need for a getter. Most tubes you will use have a separate structure in them called a getter. The getter is an element used to accelerate and deposit the trace gases still in the envelope onto the inside surface of the glass. You can see it as a silvery shiny area in many tubes. Often the getter is a small ring shaped object near the top or side of the tube. Halogen lamps get so hot they generate tungsten vapor which clouds the envlope, but the filament and the heat recombine the vapor as long as the envelope is hot enough. This is "self getting" (not gettering!) and is what the Philips people did here to some extent with this the filament in their little triode.

The 12AX7 consists of a pair of very similar triodes in one envelope.

Wednesday, December 20, 2006

Haddon Sundblom's Santa at the Shure 55S

Haddon Sundblom was a very well known American artist who did a lot of advertising illustrations of rosy cheeked people including his famous Coca Cola Santa Claus, which completely redefined the look of the merry yuletide elf.

Here is a lesser-known example sans cola but with a Shure mic instead! The date could be from the 50s up until the 60s. Sundblom was also known for his remarkable skill at depicting leggy models and did quite a few pinups that took great advantage of his ability to render skin surfaces with a vitality rarely seen today.

I have two paintings by Sundblom, who posed himself as the model for Santa Claus. Sundblom was quite the jolly guy!

Monday, December 18, 2006


Does anyone else still like Pizzicato Five?

I have several of their CDs, some of the rare P5 credit cards, and various paraphenalia. Happy End of the World and The Fifth Release on Matador are a couple of my favorites, though there are more.

That Japanese pop style appeals to my 1960's sensibilities and is still being played on Japanese internet radio even though they stopped recording long ago.

People are either amazed, amused or aghast when they hear it playing in the lab.

Saturday, December 16, 2006

More on the Martian Sinkhole


I'm not (totally) crazy.

Check out this site and scroll to the third image down, showing the same crater I have been talking about. It turns out that Keith Laney spotted the very same feature on Mars that

I said had changed recently.

I believed it was a sinkhole since it is close to and above the area of a recent outflow of liquid. Laney suggested - six years ago - that it was filled with ice. Indeed!

Friday, December 15, 2006

A Serious Thank-you from Naked Eye and Crowley and Tripp Production

Just a note of thanks to all customers who bought Soundstage Image, Proscenium, Studio Vocalist, Recordist Stereo Ensemble and Naked Eye ribbon microphones this year.

A HUGE thanks to the many independent musicians who chose Naked Eye and our other mics over competing choices.

2006 saw a big increase in the number of ribbon microphones, and Naked Eye seems to be the right mic at the right time. Naked Eye is the ribbon mic for those who want a beautiful quality and highly versatile ribbon mic that will last a career. Naked Eye's wallet-friendly pricing has advanced the Crowley and Tripp mission to get serious tools to serious musicians, at realistic prices.

Here is a link to all the pictures on our website.

Stu Personick's Ribbon Microphone

Stu Personick is an EE and experimenter in several of the physical and electrical disciplines, fellow IEEE member, and is also one of the ham types who are allowed to access free spectrum and transmit signals with high powered equipment capable of sending signals halfway across the world.

Here is a shot of his home made ribbon microphone. It has that physics department look. I have spoken with Stu and heard his wooden-framed mic on the air! Check out Stu's website here.

A Homebrew Ham Ribbon

Now I've seen it all. Here is N1NKM's home made amplified ribbon microphone.

What more can I say?

Click on the image to see his other creations.

Thursday, December 14, 2006

Lafayette Dynamic with acoustic load circa 1964

I recall seeing this mic in several old catalogs, including the Lafayette Radio Electronics catalog, and one from Allied and another from Radio Shack.

Back in the day there were numerous interesing Japanese manufacturers providing lowest-cost branded products in much the same way that Chinese manufacturers do today, with similar emphasis on looks, and economy class innards.

What is interesting about this particular piece, which has a style reminiscent of a cross between a Shure 330 and 55 Chevy grille, is the use of a stepped acoustic loading chamber, like an acoustic suspension system, to house the small and otherwise anemic dynamic element. The chamber is designed to fit into the mic body and is held in place with two screws off the back, and is made of a cast potmetal, very nicely done, and well finished. Just air inside and a little tube connected to a teeny hole at the top, which doesn't seem to do much at all. The sound from this microphone in stock form is predominantly telephonic, and capable of producing a vocal tone similar to The Black Keys.

We converted this neat looking mic body to accept a custom ribbon motor which we built and tuned for the enclosure. If you look very closely you might be able to spot the two gold plated motor mounting screws protruding slightly from the bottm. It's quite a nice sounding item now, with a fairly symmetric pattern and a lot of bass. Sharp-eyed viewers will note that the nameplate presently on this unit is a Realistic brand label. I swapped the nicer Lafayette label that was on it for another converted mic that I use on the air, at home.

Tuesday, December 12, 2006

Another mic that mightn't be

Rounding out this week's small assemblage of rare-to-nonexistent microphones is this totally unauthorized Choppers US version of an old Fen Tone dynamic or crystal microphone. That deep-drawn perforated cap must have been quite the resonant chamber, I'd suspect.

Here it is embellished with what could be a frame headbadge from a motorcycle, the iron cross or perhaps Maltese cross motif artfully integrated with wings and Civil War era "US" font. But it is not! Choppers US makes bicycles.

I've run across several of these bullet shaped mics but never one in working condition. The body is made of nicely done investment cast potmetal, and the gray paint job reminds me of something from the 1960s Lafayette Radio catalogue.

Zoom in to see what deep-drawing will do to perforated metal.

Sunday, December 10, 2006

A Prairie Home Companion - the movie

One interesting film of the last year was based on the popular NPR radio show and and in one very interesting segment, Lilly Tomlin with Meryl Streep does a live song together with Garrison Keillor. Lilly and Meryl are on RE20s (microphones shown here, in position, but from another scene) and Garrison on the 77DX. The take is pretty clearly done without an audio overdub, very well performed, and you get to really appreciate the vast difference between these two microphones on voice. Garrison's open sound contrasts with the ladies' blockier, compressed and even slightly nasal tone.

The film is a bit uneven but well worth watching, and hearing.

Seguerra Ribbon Microphone - where is it?

I do like the artsy postmodern design of this Sequerra ribbon microphone prototype which I have posted from Seguerra's site and with what I hope would be his permission had I asked. The long ribbon can be seen front and center, placed squarely between two uplifted stanchions that look like little arms. Two curved pole pieces appear to define a gap and I can only assume that in the center is something of an acoustic chamber.

Here it is to gaze at, at least for now. I do not know Sequerra but understand the brand to be mostly very high quality audiophile gear. It is my understanding that this microphone has not been released, and don't know how many, if any, were built.

Peter Costa, Prominent "Man of the Microphone" releases new collection of humor

Say hello to Peter Costa

fellow microphone user and author of his new book entitled CostaLiving: Laughing through life
which can be seen on the table between Peter and a vintage red and pink clock radio.

The book is a collection of 65 unusually funny, sardonic, witty and/or weird observations of domestic, urban and suburban phenomena, some based on the trivial, yet arguably profound frustration Costa experiences, for instance, when faced with family members who just refuse to muster adequate sympathy for his horrible head cold, (Chapter one: On suffering colds, almost in silence) or the the curiously familiar but inevitable dread when the author is faced with replacing the CV joints in his front-wheel-drive station wagon. And it is funny! Funny in a way that can make you chuckle hours and even weeks later. Short story fans will appreciate Costa's Thurber-esque form of present-day Americana flavored with an occasional ad lib in Latin, or brief nod to the classics.

Pick up CostaLiving: Laughing through life (get the pun?) at bookstores, (if you can call them that anymore), like Barnes & Noble, or online, at Or here on his website.

from the back cover:

About the author: Peter Costa is a veteran journalist who has worked for weekly and daily newspapers, national magazines, and an international wire service. He covered the United Nations and interviewed four US presidents and has the stolen stationery and ashtray to prove it.

additional info:

Costa is licensed as W1ZZZ by the Federal Communications Commission and operates his personal radio station from his home in Massachusetts. Peter is often heard on the frequency of 3885 KHz shortwave, where he talks with others about many of the subjects in his new book, often at great length.

Interesting Homebrew Ribbon Microphones

Here is a shot of a home made ribbon microphone and frame that is built out of six pieces of iron and a couple of flat magnets. You can't see the ribbon which is well in the middle of the magnets which are quite wide and not very long.

This motor unit was made to measure the flux density of the gap with and without back iron. The advantage of back iron is that it increases the magnetic field strength, and the disadvantage is that it represents an acoustic obstacle and therefore limits the high frequency response.

There have been a couple of licensed public spectrum users (what I once referred to as "ham" radio) who I have spoken with who have recently built similar home constructed ribbon mics and put them on the air recently. The public has access to spectrum for this type of on-the-air experimentation in most countries of the world. Generally referred to as "amateur radio", the resource is gradually being accessed by a new generation of experimenters and others who want to have free access to some usable spectrum for personal communications and for scientific, engineering and educational purposes. To access spectrum in your country, you may or may not need a license, depending upon the portion of spectrum you wish to use. Generally if you want to get good distance you must use fairly high power, which requires a simple license indicating you know how to use it safely and without making a lot of interference or noise which would disrupt others.

There are a lot of people doing long-haul Wifi, for example, and getting free internet access as a result.

Friday, December 08, 2006

Another PAR Award for Naked Eye

Naked Eye by Crowley and Tripp won a second PAR award for the company at 2006 AES in San Francisco. Here it is in Coke bottle green this time, a departure in color and with updated artwork. Pro Audio Review, sticklers for correct copy, have now spelled "Crowley and Tripp" in the proper way, too.

It is an honor to recieve this second consecutive award and we thank Pro Audio Review and their roving selection committee for picking the Naked Eye ribbon microphone as a top choice in innovative pro audio gear The customers seem to agree that once you compare the Naked Eye ribbon mic against its peers, some costing much more, Naked Eye's high output, low noise performance, super build quality and great sound make the choice an easy one. And the price is the most wallet friendly of all the current pro quality ribbon mics too.

This is a good time to say thanks to everyone including dealers and customers who have amazed us with their tales of success with Naked Eye, which appears to represent a new standard of ribbon mic quality and value. Each Naked Eye ribbon microphone is hand made in the USA by people who know the art and science of sound.

Thursday, December 07, 2006

Possible Source of Martian Outflow Identified by Researchers

Ashland MA USA: Researchers at a Massachusetts laboratory reported today that they have spotted a possible source of the recent Martian outflow that has excited scientists and opened up the possibility of finding life on Mars. According to the researchers, the possible source is a sinkhole located North of outflow location. NASA images were used to identify and compare time lapse changes on the Red Planet's surface. "The direction of the outflow corresponds almost exactly with a change on the other side of the crater's ridge" remarked laboratory researchers. "This may be the first time we have been able to observe a sudden change in Martian geology and a susequent release of liquid water. It could mean that there is a lot of underground water on Mars" said Robert J Crowley, who works at the laboratory.

The new sinkhole can be seen to the North of the crater's rim, and appears as a roughly circular feature that appears to have darkened and become larger and deeper when compared to earlier images of the same location.

You might recognize these recent NASA images of the surface of Mars, the left image shot in 1999, the right image more recently. The obvious white feature is presumed to be evidence of a flowing liquid, perhaps water.

What many people might not appreciate is that this is a stereo pair that can be viewed in crosseyed stereo, a technique that is easy to learn and use to view full dimension stereo images without special glasses. In a nutshell: Sit with you head level to the two images at a comfortable reading distance. Slowly and gently cross your eyes until two images combine to form a third, fuzzy image in the center. Relax! In a minute or less the fuzzy image will fuse into one incredible stereo image.

Give it a try. You can do it.

This is one great stereo image and it has a surprise in it for those who view it in stereo.

Here is a hint. Notice the location, orientation and elevation of the flow relative to the steep ridge. Imagine the origin of the flow. Now look at the other side of the ridge, in stereo.


Of course there is a direct analogue to stereo recording here. The human brain, plus eyes and/or ears, is great at detecting differences in position, and differences in time. Once you get a good look at what I am talking about you will recognize how sensitive this comparative ability of our binocular visual sensor systems really is. The stereo pair above contains brightness (amplitude) spatial, (position) and time domain information - in this case time over several years. Your pair of brain-controlled ears are equally sensitive to very fine nuances of loudness, time (phase) and position.

It appears that in addition to a new "river" there may be a new sinkhole on Mars. The surprise (for those who tried and succeeded in getting a good stereo view) is an apparent depression North of the ridge, directly in line with the origin of the newly observed flow marks on the surface. This is an exciting observation first reported here! (But sinkholes on Mars are well documented - see here)

And there is an interesting discussion group about Mars images here.

Early Theory of the Mars Sinkhole and River: I will hazard a guess that subsurface ice has melted at the North ridge, and the liquid found its way downhill through fissures or perhaps a sand bed below the ridge, and exited at the crater wall, forming the gully. If this is the case, there may be widespread subsurface ice which could be comprised of either carbon dioxide or water ice. I think that carbon dioxide is the more likely material since the average surface temperature on Mars is too low for water to remain liquid, however a South facing escarpment, as is the case here, exposed to generous sunshine, could be a relative hot spot. Maybe this is the best place to catch some rays on Mars!

It should be worthwhile to look for other sunken areas with similar temperature and geologic locations to se if there are any corresponding flow-like features radiating away from the sunken area.
Robert J Crowley


Tuesday, December 05, 2006

Federal Communications Commission and Ribbon Microphones

In the US, the Federal Communications Commission (FCC) is the primary regulatory body empowered to develop and enforce rules and regulations pertaining to the use of electronic equipment that interacts with radio wave energy. The FCC also regulates cable TV and even the content of radio and TV broadcasts, and levies fines on broadcasters who violate the rules as they are interpreted at the time. The US is an odd place where allowed TV content consists of obscene amounts of violence and depictions of hatred, destruction, murder and gore that are well-tolerated by the FCC, yet virtually any depictions of sex, naked human bodies, lovemaking or natural human processes are forbidden, unless they are images of nude saints or classical paintings of nymphs or other Fine Art forms. Even these are usually masked in such a way so the essential bits are missing.

But we like the FCC anyway, because they are the regulatory body that sets the standards for RF emission and immunity in electronic equipment. For instance, the FCC requires that most consumer electronics meet what are referred to as the Part 15 rules. This means that a preamp, for instance, or an amplified microphone such as a condenser or even a ribbon microphone with an amplifier in it, must be tested and certified by the manufacturer that it won't exceed certain limits of RF radiation. This helps everyone because it keeps the level of noise down and reduces the propensity of various electronic devices such as PCs and mixing boards to interfere with each other.

You can look on the label of any active electronics to see if it has the FCC symbol on it. You will often see the CE mark, which is essentially the same rule for Europe, and TUV and other symbols that variously indicate that the device conforms to the particular country or regional rules. Manufacturers who do not do this with their active electronic devices are taking a chance. In one case, a prominent audio manufacturer was fined for faking the FCC Part 15 certification on its equipment.

All Crowley and Tripp Ribbon Microphones are passive devices and have no amplifiers or active electronics in them. Yet we do conform to RF immunity testing according to the Electromagnetic Compatabilty Regulation 2005 - (S.I. 2005/281), The Electrical Equipment (Safety) Regulations of 1994 (S.I. 1994/3260), CONSLEG:1989L0336-02/08/1993, FCC Part 15 CE. We test our microphones for RF susceptibility to various RF sources and also low frequency electromagnetic fields, and we design the microphones so they will be as immune as we can make them to those sources of interference. A low noise floor is important! We also compare our RFI immunity against competitors, and we believe we have better RF and magnetic shielding than others we have measured.

That FCC logo is somewhat odd one but one that I like: It shows an eagle carrying some radio waves (or destructive lightning) over to an antenna installation. It even show a pair of towers, a wire strung between them, ham radio style, and a transmission line.keyword fcc royer Robert J Crowley Bob Crowley behringer