Live Sound

Dana Jae's blog

Why, you may ask, is the microphone the most important element? Well, without one you can't record sound sources, or amplify them. So this time I'm going to talk about amplifying sound in a live sound environment, and why there is actually an important difference between mics for live sound and those used in the studio.

Dana's Recommended CD
	Blame Sally, Blame Sally
Dana's Recommended Mics and Gear: Blame Sally uses several different microphones: the Audix OM7 and Audix OM5, the Beyerdynamic Soundstar II, and a Shure SM58. I love Audix vocal mics, as you can get a lotof gain before feedback out of them. They are particularly suited to singers in loud rock bands. (This is not a loud rock band, however.) For the instruments, I used a Shure SM57 microphone on the percussion and a host of Countryman direct boxes on the rest of the acoustic instruments and the keyboard. A direct box enables you to take an instrument cable from a bass, keyboard, or acoustic guitar and change it to a balanced line that can run long distances to the mixer. A typical instrument cable is unbalanced, and can induce noise if run longer than 30 or so feet. If there is a lovely piano in the vicinity, I mike it with a couple of AKG C414s or a Shure SM91 PZM microphone. The other band that day, Deep Six, needed a ton of microphones. They had a drummer, a percussionist, a bass player, two guitar players, a keyboard player, and two saxophonists — and five of them sang. So we're talking pedal-to-the-metal sound system and mixing. I only had 16 channels, so in order to save space on the console I used three microphones on the drums rather than my usual seven or eight. I had a Beyer M180 mic, one of my faves for kick drums, and a Shure VP88 stereo mic over the top of the kit to pick up the rest of the drums and cymbals. On the percussionist, I used two Shure SM57 microphones over the tops of the dual sets of combined congas and bongos to pick up all of them. The Shure SM57 is the most widely used microphone on the planet. It never lets you down, has an excellent sound for miking instruments of all types, and is usually the one mic that any engineer would die with. Yup, put it in the casket with me! I placed additional Shure SM57s in front of Deep Six's guitar amplifiers. No matter how loud a guitarist plays, you'll always want a little more at some point. Though you may not use the mic all the time, when you need it, it's there. (They can't tell how loud they are playing from the stage, you know. This is why I have to shake my finger at some of them, like a momma reprimanding her kid. Most play too loud.) I used a Countryman direct box on the keyboard and the bass, and a few different vocal mics on the band. Some engineers stick with the same manufacturer, make, and model to mike all the vocals in a band. I say "bah-humbug" to that! Every voice sounds different through various mics, and it's important to pick the right one for YOUR voice. One of the firemen had bought himself a Shure 55SH vocal mic. It looks really cool and vintage. (And judging from his cool gig shirt, you can see why "stylin'" is very important to him.) This mic looks so cool that you'd think Elvis just walked off stage. It has a fine sound for the male voice (good reproduction of the lower midrange). I used a Shure SM58 for his pappy, who stood right next to him playing guitar. The keyboard player had a Sennheiser E835 that he had recently purchased. It sounded great on his voice, though at first I wasn't too sure if it would give me enough gain before feedback. For the rest of the band, I used the Audix OM7 vocal mics that I have come to know and love for live sound. Alanis Morisette, Bonnie Raitt, and Crosby, Stills, and Nash are big Audix vocal mic fans as well. A few other mics of note: • Sennheiser E609s are particularly good on guitar amplifiers. I love the Sennheiser MD421U (a standard for years) on tom drums and saxophones. • Both Audix and Shure drum kit packages are well worth the investment. The Audix D2 and D4 are quite good, and I've already mentioned the Shure SM57 on drums…love it. Their Beta 52 kick-drum mic has a BIG sound. • If you're a vocalist who wants one of the best live mics and you don't have a really loud band behind you (say you accompany yourself on piano or acoustic guitar), you will love the Neumann KMS105. It's lovely, but a bit pricier than most others noted here.
	Audix OM5 Dynamic Microphone
	Audix Fusion 7 Drum Microphone Package
	Neumann KMS 105 Pro Stage Condenser Mic
	Shure SM57 and SM58 Microphone Package
	Shure 55SH Series II Cardioid Dynamic Microphone
	Shure Beta 52A Kick Drum and Bass Microphone
	Sennheiser E609 Silver Dynamic Guitar Microphone
	Sennheiser E835 Performance Vocal Microphone

Blame Sally(Photo: D. Ross Cameron)

The members of Blame Sally offer a perfect example of the proper use of microphones and mic technique in live performance. Let's go over some of the basics.

Different types of microphones with different pickup patterns (also known as polar patterns) are used for various purposes onstage and in the studio. Omnidirectional mics pick up sound from every direction — a complete no-no for most live bands, where the whole idea is to isolate the sound of each instrument as much as possible. Bidirectional or "figure eight" mics pick up sound from both the front and back. For live sound, the pickup pattern that's most useful is the cardioid (heart) shape, also known as unidirectional. (Hypercardioid and supercardioid patterns are variations of this shape.) A microphone with a cardioid pattern picks up sound from the front of the mic and rejects sound from the back, which is, of course, ideal for live vocals.

An omnidirectional mic pickup pattern.       A cardioid mic pickup pattern.

Most vocal mics used in live sound are dynamic microphones. This means that there is a moving-coil magnet inside the mic that reacts to sound pressure level (SPL). It moves back and forth in relation to the pressure of the sound waves, creating voltage. These mics are excellent for loud SPL, like you'd get from a kick drum. Your ear works like a moving-coil magnet, sort of. (No, don't put your ear up to a kick drum while someone is slamming it!) There's no magnet in your skull (at least that I know of), but like a dynamic mic, the ear has a membrane that reacts to sound pressure level. This is how you can tell the difference between a whisper and a shout into your ear.

Of course, there are other types of mics besides dynamic microphones, but they are not as commonly seen onstage. A condenser mic uses a capacitor to store a charge that is either provided through the mixer via the mic cable (this is known as "phantom power") or through a battery. Condenser mics are widely used in studios, and have an excellent frequency response. Then there are ribbon mics, which sound amazing but are rarely used in live sound for vocals, as the usual pickup pattern is bidirectional — the mic would pick up both the vocalist and the guy hooting and hollering in the third row.

Because dynamic mics work well in reacting to loud SPLs, we use them in front of electric guitar amplifiers, drums, horns, and voices onstage. But wait a minute, you might be thinking: What if the singer in my band sings really softly? Is this still the right type of mic to use? Unfortunately, if you're in a band that has drums, electric/electronic instruments, or loud sound sources, and you want your vocalist to be heard, you need to use a dynamic microphone. In live sound, it takes gobs of power to make the sound system loud enough for an audience to hear. (After all, PA stands for "Public Address.") This uniquely large amount of power is known as "system gain." And as loud as you make the instruments, you have to make the singer even louder, and still avoid feedback.

One important concept in live sound is "gain before feedback." A good live vocal mic has to have maximum rejection of the feedback that can be generated by stage monitors that blast the sound of the mic back at the singer. This is a key reason why you can't use a studio microphone on a pop music stage. You'd get that horrible ringing "SHREEEEEEEEET" in the sound system. That's when the audience runs for the door. Eeeeks!

Dynamic mics with a cardioid pickup pattern are necessary for rejecting feedback. You can increase their gain enough to make a sound heard above the din, but not interact negatively with the huge amount of system gain that's rolling through the PA system. (It's called physics, my friends, and there is a lot of information that I must leave out for the sake of space.)

But there's more to using a microphone than just plugging it in and singing. To get the most out of a performance, good mic technique is essential. Check out these photos of Blame Sally: You can see that the singers are very close to the microphone. Dynamic mics sound best when you are practically "eating" them. You hear the fullest part of the tone of your voice (the rounded lower-midrange) when the singer is close to the mic, and a far more diminished sound when he or she backs up just a few inches.

Jeri Jones from Blame Sally. (Photo: D. Ross Cameron)

Monica Pasqual from Blame Sally. (Photo: Tom Erikson Photography)

When singers with good technique (like this band) work the mic, they get real close when singing quieter parts and pull away a bit when belting out a loud note. They also back off a little when singing backing harmonies, so the person who is singing lead stays in the front of the mix.

You've probably seen this in action if you've ever caught a close-up of one of those big-name singers in concert. (Whatever you think of Celine Dion, the lady does have good mic technique, people!)

Now, when you see a rapper "spittin'" on the mic (not literally; it's a hiphop term) and he or she has their entire fist wrapped around it — well, um, that is NOT good mic technique, as it cuts off much of the mic's pickup pattern. Same thing when you see Mick and Keith doing a vocal thing together on one mic, each one from the side of the mic: That's not good technique either, as the mic picks up sound the best from the front. (Well, it does look cool, though. And both rock and hiphop have a lot to do with looking cool, no?)

Finally, vocalists, here is an important tip: Do yourself a favor. Buy yourself your own microphone and take it to every gig. This is your instrument, and you should definitely have your own. If you're using the club's house microphones, you never know what the person who sang before you has done with the mic you're about to use. Years ago, I saw the lead singer of Fishbone do something so disgusting with his mic that I ran out to the store THE NEXT DAY to get myself one. I've never turned back!

Posted September 2006

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