Utilizing Ribbon Mics for Live Sound

I discovered ribbon mics late in my career, after I’d been engineering for 20 years. I only knew the classics before that, such as the RCA 44 and 77-DX, which looked great in glass cases or featured in photos of music stars of previous generations. About 2001 I started using some of the newer generation of ribbon mics and I fell in love with them: the Royer R-121 and R-122, the AEA R84 and R88, along with standards such as the Coles 4038 and Beyerdynamic M160 and M500. I was hooked, with my ribbon mic collection eventually topping out over a dozen mics, ranging in date of origin from 1932 all the way to the present. But I used them primarily in the studio and became very familiar with their strengths. I learned to love the figure-8 pattern and recognize where it truly excelled.

In the studio, I use ribbons on drums as room mics, on electric guitar cabinets, on woodwinds, strings, brass instruments, and percussion. They can handle the high SPLs in front of a kick drum (though not necessarily inside a kick) or staring down the bell of a trumpet. But what about live situations? Are there applications where those strengths could be applied in far less-controlled scenarios? After some experimentation, the answer is a resounding “Yes.” Let’s examine how you can get great sound using ribbons on a live stage, while also addressing problems that you may frequently encounter.

That Ribbon Sound

For electric guitars — which is where most engineers primarily think of using ribbon mics — there are just as many reasons to use ribbons for live as there are in the studio. Firstly, they are great for their wonderful, unique sound compared with condensers or moving-coil dynamic mics. They have a smoother sound that some people believe truly mimics the human ear more closely than other mics, without the typical “tizz” (AEA’s Wes Dooley’s word for the narrow resonances in the 8k to 12k Hz range) of a tautly stretched condenser mic’s diaphragm or the pointed midrange of a dynamic standard like the Shure SM57.

For loud electric guitars, this relaxed presentation smoothes out the cutting midrange of overdriven amps, while yielding a low-mid push that offers powerful tone. For percussion, nothing captures the skin of a conga’s head quite as well. And on drums, they capture all the brilliance of crash cymbals without the ear-splitting sizzle. Chad Cromwell, prominent Nashville session player and Neil Young’s touring drummer, likes to keep a ribbon over his kit for monitoring. He says he feels more connected to the drums because he hears them far more naturally.

Whether ribbon mics are truly more “accurate” or not, for my taste I just like the way they “hear” via their incredibly natural sound. In addition to electric guitars and drums and percussion, I use them as spot mics on woodwinds such as oboe, clarinet and sax, and I can get the tone of the instrument — without picking up mechanical noise from the keys and pads. For woodwinds, I use a Royer R-122 with no other processing whatsoever (so long as there is no rumble from air movement or traffic, in which case I might need to add a high pass filter), and due to the low-frequency extension, I always use a shock mount because a vibrating stage floor will come through loud and clear. For me, straight and flat (no EQ) is always the best possible solution. One mic in the right position? Done! The same is true when I put an AEA R-84 on trumpet, about two feet away from the bell so that I don’t pick up the sonic gremlins from miking it too close, then straight into the preamp. Perfection.

I like to use an R-122, R-121, or RCA 44-BX or 74 on trombone into a preamp with plenty of girth, and I’ve got a killer sound with no fuss. And the best part about using ribbons on brass is that I get all the tone and warmth of the instrument without any stridency or stress when musicians play really loud. Although it’s not really compression in the typical sense, it keeps the sound just right in the mix without screaming through. Any mic that gets a great sound and makes my job of mixing easier is the preferred tool for me.

We Don’t Need No Stinkin’ Leakage

Some people object to the thought of using a figure-8 mic onstage because of the “bleed” from the back of the mic. They mistakenly think that a cardioid or hypercardioid offers greater rejection of unwanted sounds. Sometimes that is true, when lots of players are tightly smashed together onstage, but there are times when a figure-8 ribbon will actually offer greater isolation and better sound than a cardioid. When you have a row of brass players standing shoulder to shoulder, a situation that I’ve encountered lots of times, the separation between the individual horns on a figure-8 ribbon (with one mic per horn) far exceeds the isolation of a cardioid mic. When the adjacent players are in the “null” (the area that is 90 degrees off-axis) there is absolute cancellation, so you can have a trombone player standing right next to the trumpet player and barely hear the trombone sound on the trumpet mic at all. Plus it sounds better. I’ve used ribbons on brass in live situations lots of times. They sound amazing.

Let me offer another example of when a ribbon works better than a cardioid dynamic. I had a percussionist who was playing congas just a few feet in front of a 120-voice choir — a very loud, enthusiastic gospel choir. This was for a live show that was also being recorded for a subsequent live release. By putting an R-122 directly over the congas with the ribbon horizontal, parallel to the stage, so that the choir was directly in the null of the figure -8 pattern, I got a great conga sound and inconsequential bleed from the choir.

But what about the leakage into the back of the mic? Well, there’s this law called the inverse distance law that states “sound pressure is inversely proportional to the distance from the sound source.” (See Fig. 1, top) The formula means that under controlled conditions, direct sound drops by 6 dB every time it doubles in distance. While it’s not quite that simple in a live sound environment with lots of reflections, it still means that sounds entering the back of microphone will be softer based on their relative amplitude and distance from the microphone. With the typical gain structure required for a mic that is right in front of a guitar cab, the incoming signal from behind the mic (unless it’s stupidly loud or very close) is going to be lots softer by comparison. There are also some unidirectional ribbons like the AEA KU4 or legendary Beyerdynamic M160 that is a unique hypercardioid double-ribbon mic that minimize sound leakage from the rear. Alternatively, there are some clever compact solutions like sE Electronic’s guitaRF Reflexion filter to keep sounds out of the back of a ribbon mic.

Won’t They Break?

But what about durability? Well, I’d never take my 1932 RCA PB-90 or my 1960 RCA 77-DX out on the road, but I have no qualms about using my current generation ribbons in live settings. Royer mics, such as the Live Series or the affordable R-101, are incredibly durable and will hold up to live use with a modicum of precaution. Don’t blow into them! (“Mic test: Hoo-hoo.”) The AEA N22 is another very durable choice. Others such as the Shure KSM313/NE even offer ribbons made of Roswellite, which utilizes carbon-nanotube technology to make them virtually indestructible.

Who Would Use Ribbons on the Road?

If you decide you want to use ribbon mics on the road, you’ll be in good company. Royer Mics’ John Jennings related this story: “When Aerosmith’s Just Push Play tour started in 2001, Joe Perry’s guitar mics were picking up too much sound from other instruments on the stage. The problem was solved by putting five Royer R-121’s on Perry’s cabinets, a practice the band continues to this day. All sounds approaching the sides of the mic were eliminated — bleed problem solved. And the tone was killer! And he appreciated being able to use the same mics on the road that he used in the studio.”

And Aerosmith is not alone in this “live ribbon” camp. Here are some current touring artists and how they are using ribbon mics on the road. Capturing guitar amps with ribbon mics also seems to be a popular choice with acts such as Keith Urban, Matchbox Twenty, Brian Setzer, Muse, Johnny Marr, Stereophonics, Return to Forever (Al Di Meola’s electric guitar), the Goo Goo Dolls and Fleetwood Mac. Ribbons have also been a traditional favorite mic choice on brass instruments, such as on Arturo Sandoval’s trumpet and brass sections for Harry Connick, Barry Manilow and others. And among the artists that use ribbon microphones on a variety of sources include George Strait (electric guitars, pedal steel, drum overheads); Maroon Five (electric guitars, stereo ribbon mic for audience recording); Phish (electric guitars, drum overheads) and Crosby, Stills & Nash (guitars).

If ribbon mics work for these artists on the road, maybe it’s time you considered giving ribbon mics a try for your next live sound gig.

A noted audio engineer and journalist for more than three decades, Lynn Fuston is the manager of written content for Sweetwater Sound’s web and print content. For more, check out Sweetwater’s live sound articles at www.sweetwater.com/insync/live-sound-expert-advice.

Ribbon Microphones: The Revolution Continues

Just over 85 years ago (March 31, 1931, to be exact), RCA engineer Harry F. Olson filed his patent #1,885,001 for the first ribbon (velocity) microphone, and the audio world hasn’t been the same since. The design had the now-familiar figure-8 polar pickup pattern, but compared to the omnidirectional mics in use at the time, the invention turned out to be a revolution in transducer design.

Noting the earlier research of some Siemens engineers on replacing speaker voice coils with a metal ribbon design, the pair applied the ribbon approach to microphones, first with field coils and later with permanent magnets, resulting in the first ribbon mics (the PB-17 and PB 31), which offered the advantage of a bi-directional pickup pattern. See Fig 2, left.

In 1931, the PB-31 was replaced by the 44A, which was enormously successful and highly regarded for its smooth tone and defined pattern control, which not only reduced the effects of reverberation on soundstages, but also offered higher gain-before-feedback in live sound applications.

Although there were certainly improvements over the years by both RCA and other manufacturers, it is impressive that this original design — which uses a thin ribbon of metal suspended between the poles of a magnet to produce a figure-8 pattern — remains with us to this day. —George Petersen

Ribbon Mic Manufacturers

Ribbon mics seem to be at an all-time high in popularity, based on the number of recent entries in the market. Not all of these models are ideal for live applications, but in audio, sometimes rules are made to be broken. —George Petersen

Audio-Technica: www.audio-technica.com

AEA: www.ribbonmics.com

Apex: www.apexelectronics.com

ART: www.artproaudio.com

Avant Electronics: www.avantelectronics.com

Avlex/Superlux: www.avlex.com

Beyerdynamic: www.beyerdynamic.com

Blue: www.bluemic.com

CAD: www.cadmics.com

Cascade: www.cascademicrophones.com

Cloud: www.cloudmicrophones.com

Coles: www.coleselectroacoustics.com