Ribbon Mics

AEA KU4 Unidirectional Ribbon Microphone

AEA KU4 Unidirectional Ribbon Microphone Details

The AEA KU4 celebrates the legendary RCA unidirectional KU3A, a high-sensitivity microphone designed for the Hollywood movie studios. Also known as a M-10001 for its manufacturing number, it was RCA’s most expensive ribbon microphone. Fewer than 600 were ever manufactured.

What made the KU3A special? It combined the smooth ribbon sound of a 44 with a unidirectional pattern, a wide sweet spot and less proximity bass boost. It expanded an engineer’s range of placement choices and became a standard at film studios around the world.

Pro Audio Network: Ribbon Mics

What is a ribbon mic and how does it work?

Ribbon microphones have been around for over 75 years and are just as popular now in the digital age as ever. When ribbon mics first hit the scene they were highly regarded for their uniform frequency response. Ribbon mics operate on the principal of electromagnetic induction, which places them in the dynamic microphone category. The ribbon is traditionaly constructed of curragated aluminum; however, new designs make use of duraluminum and nanofilm. This material is suspended in a magnet, which produces magnetic flux lines across the ribbon element. Sound pressure from either side of the ribbon causes the ribbon to vibrate and cut across the flux lines of the magnet. This produces a signal that is directly proportional to the amplitude and frequency of the sound source. The signal that is generated is usually of a low voltage and needs to be stepped up with a transformer. Ribbon mics often require more preamp gain than condensor and dynamic mics, and often require a higher input impedance at the mic preamp. For these reasons, ribbon mic-specific preamps have been designed, like the AEA RPQ, AEA TRP, and Cloud Cloudlifter Ribbon Microphone Preamp.

What are the different types of ribbon mics?

There are two different types of ribbon microphones: active and passive. Passive ribbon mics do not require phantom power and generally have a quieter output than actives by as much as 20 dB. Passive ribbons typically do not have any EQ alterations built into the internal circuit. The AEA R44 and AEA R84 are two popular passive ribbon mics. Active ribbon mics require phantom power for the amplifier circuit in the mic. A few popular active ribbons are the Cloud JRS-34 Active Ribbon Microphone, AEA A440 Ribbon Mic, and AEA A840 Active Studio Ribbon Microphone.

Ribbons in their most natural state have a bi-directional polar pattern (figure-eight pattern - the rear side is opposite polarity from the front). However, some companies have tailored the diaphragm to produce more directional polar patterns. One example is the Beyerdynamic M-160, which has a hypercardioid polar pattern. Note that since ribbon mics are directional, the proximity effect can be used to naturally enhance the bass response by moving the mic closer to the source. New ribbon mics utilize higher quality transformers (as well as tubes – like the Royer SF-24V Stereo Ribbon Mic) to improve signal quality and reduce high frequency loss when using long cable runs. The Royer R-101 is a newly released ribbon mic that provides great sensitivity, and durability against high SPL. Another interesting new ribbon is the sE Electronics RNR1 Ribbon Microphone by Rupert Neve. This mic is designed with custom transformers to overcome the common dark top-end of ribbon mics and decrease noise levels.

Ribbon lengths and designs

Since ribbon elements are very light weight, they respond very well to transients. However, there are different ribbon designs. Generally, shorter ribbons have fast response times, slightly increased upper mid-range presence, and earlier high-frequency roll-off, while longer ribbons provide extended low and high frequency responses. An example of the short ribbon design is the Beyerdynamic M260. One long ribbon design mic is the Apex 210. Another is the Peluso R14. The dual short ribbon design increases the microphone’s sensitivity, lessening the need for extra preamp gain. The Beyerdynamic M130 and CAD Trion 7000 are two examples of dual ribbon design.

Why buy a cheap ribbon? Why buy an expensive ribbon? What are the major differences in build quality?

A lot of companies are designing new ribbon microphones. Some are very affordable and some are more expensive. So what makes the more expensive ribbons better? One thing to consider in a ribbon mic is the quality of the transformer, as the transformer has a dramatic effect on the tonal characteristics of the microphone. Another thing to consider is the material of which the ribbon is made. Some mic manufacturers still use NOS ribbon elements and some utilize modern nanomaterials. Some of the more exclusive designers who produce small amounts of quality microphones generally have stricter regulations on the ribbon element and internal electronics. With these regulations in place, each mic of the same model is as close to identical as possible.

One advantage of buying a less expensive ribbon is the option of modifying the mic. Cheaper ribbon mics are good for this because you can really improve the sound of the mic with only a little bit of extra investment, and if you make a mistake, you haven’t thrown a bunch of money down the drain. The Apex 205 is a popular inexpensive ribbon mic that often gets modded. There are some tutorials and sites with modding information on the web. Check out the links section for a couple of examples. Also, guys like Michael Joly at OktavaMod will modify your mic for you if you don’t want to get into the nitty-gritty of DIY modding. Michael Joly also sells pre-modded mics.

Practical applications of a ribbon mic

Ribbon microphones have been used for a variety of purposes. There is a reason why cutting-edge studios use this 75 year old technology. One of ribbon microphones’ most popular uses is for vocal recording and broadcasting. They are also extremely useful when dealing with horns, percussion instruments, and also for miking guitar cabinets thanks to their common, gentle high-frequency roll-off characteristic that can smooth out the tone. Many engineers have found that a quality ribbon will sound good on nearly any source, as it reproduces a very natural representation of the sound that fits well into a mix, and takes to equalization very well.

Due to their figure eight pickup pattern, two ribbon mics are often used in conjunction to form a Blumlein microphone array. This is a stereo miking technique that involves placing the mics coincidently (their diaphragms as close as physically possible to each other), aimed 90 degrees apart like an X/Y array.

Taking care of a ribbon mic

It is generally recommended to store your ribbon mics with the ribbon element pointed vertically. This helps to prevent the ribbon from being stretched by gravity. However, some ribbon mics have been designed to allow for horizontal storage. Check the manual of your microphone for information on this.

Another factor to take particular notice of when using ribbon microphones is phantom power. Ribbon technology was designed before phantom power came into existence. Thus, some ribbon mics can actually be damaged if you apply phantom power. However, most modern ribbon mics are designed to properly deal with phantom power, and won’t be damaged as long as the XLR cables used are properly wired. Of course, active ribbon mics actually require phantom power. If you are using a patch bay, it is a good idea to turn phantom power off (and allow enough “ramp down” time) before you patch in or unpatch mics.

Another aspect to be wary of when using ribbon mics is the sound pressure level (SPL) of your source material. High sound pressure levels can damage some ribbon microphones, and constant exposure, particularly to very loud low frequencies can cause a ribbon to stretch. It is generally a good idea to limit your ribbon’s exposure to high SPL when it’s not necessary. Also, keep in mind that wind and bursts of air can damage a ribbon. One way to help prevent this is to use a pop filter to prevent large gusts of air from stretching or tearing the ribbon element. Royer makes the WS12 Furry Windscreen and WS58 Foam Windscreen, which can be placed on a Royer microphone to prevent wind from damaging the ribbon element.

Though ribbon mics were once a fragile and delicate type of microphone, many modern ribbon mics have taken advantage of more recent technologies to make ribbon mics more durable than those of the past.

Videos:

Interview with Wes Dooley of AEA

Wes Dooley visits Front End Audio

Coles 4038

Coles 4038 Studio Ribbon Microphone Details
The Coles 4038 Studio Ribbon Microphone was designed by the BBC as a broadcast recording microphone with exceptionally flat frequency response from 30 Hz to 15,000 Hz. The Coles 4038 provides a natural, smooth sonic quality and textured response to the sound signal. A 4069 XLR Connector and Rigid Mic-mount are supplied with the microphone. From distorted guitar to classic grand piano describes the widely diverse applications in which this microphone is used. Many of the leading record producers use this classic mic in any number of applications. The 4038 has become one of the primary tools of choice throughout the recording industry.

AEA A440

AEA A440 Active Ribbon Microphone Details
With the release of the A440, AEA has synthesized more than 30 years of experience with high performance microphones. The A440 is the quietest ribbon microphone ever produced. The A440 combines all the warmth and beauty of the classic 44, both sonically and visually, but with a signal so hot you'll have to try it to believe it. Like the rest of AEA's Big Ribbon Mics, it needs little EQ, takes it nicely when you want it, and is free of resonances in audible range. The A440 is unlike any other product on the market today and no professional studio should be without one.

Beyerdynamic M160 Double Ribbon Microphone

Beyerdynamic M160 Double Ribbon Microphone Details

Beyerdynamic M160 is a classic ribbon microphone, spoting a dynamic double ribbon element. Featuring a hypercardioid polar pattern with a noise attenuation of 25 dB at 110-degrees, the M 160 is an outstanding microphone which is very effective for all types of remote and in-studio voice reproduction. In the recording studio, the M 160 is recommended for miking string instruments such as violins, violas, cellos and for pianos, saxophones as well as for hi-hat and toms. The non-glare black surface of the M 160 and its small dimensions allow the unobtrusive use in TV or film studios. In conjunction with the M 130 dynamic double ribbon microphone the M 160 is ideal for stereo recordings in MS technique.

Royer R-121 Ribbon Microphone

Royer R-121 Ribbon Microphone Details

Released in 1998, the award-winning R-121 is our flagship microphone; the world's first radically reengineered ribbon microphone and the model that reintroduced ribbon mics to engineers around the world. We did away with the large, heavy, fragile "classic" approach to ribbon microphones and went in a completely new direction. The R-121 gives all of the warmth and natural sound that experienced engineers have long turned to ribbon mics for, but in a compact, light-weight, high output and tough-as-nails package that was unheard of in a ribbon mic before the R-121. In its 10+ years in the market, thousands of R-121's have been sold around the world and it's well established as a standard for tracking electric guitar and brass.

The R-121 redefined ribbon microphones so completely that Recording Magazine wrote "...the Royer R-121 is destined to become one of the classic microphones of the 21st century."

AEA R84 Ribbon Microphone

AEA R84 Ribbon Microphone Details

The AEA R84 is an affordable Large Ribbon Geometry (LRG) microphone suitable for use by the most demanding audio professional or hobbyist.

If you are new to ribbons, you are in for a treat! Experienced users have discovered the AEA R84 is an outstanding general-purpose microphone, ideally suited for solo and accent work. It is hard to find an application where this mic does not shine. It is a fine example of the natural sound and figure-8 directional sensitivity a quality ribbon mic delivers.