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6 SMART, PROVEN METHODS TO
CONTROL FEEDBACK ON STAGE

(WITHOUT EQ)

There is nothing worse than spending an entire event struggling
with feedback demons. You may have been taught to fight feedback
with a graphic EQ, but there is a better way. Actually, that's not
true: there are six better ways. Use my guide to controlling feedback
onstage and mix in fear no more.

The feedback frequency is determined by resonance frequencies

in the microphone, amplifier, and loudspeaker, the acoustics of the
room, the directional pick-up and emission patterns of the

microphone and loudspeaker, and the distance between them." -
Wikipedia

Method #1 - Microphone Placement

Close Miking
For loud stages and busy rooms, close miking is generally the
way to go. It might not always be the best for sound, but for the
maximum gain before feedback, you have to kiss the mic.
Remember, with each doubling of distance, sound level is cut in
half. Plus, if you're working mostly with Shure SM58 and SM57
microphones, that's how they are designed to be used anyway.

For corporate audio this usually means teaching your presenter
how to handle the mic. For theatre this means adjusting headworn
capsule placement. I have seen sound designers successfully mic a

play without headworn microphones, but it's tricky (see How To
Mic An 800 Seat Theatre With Floor Mics).

Polar Pattern

For concert sound you almost never use an omnidirectional mic.
Microphones with a cardioid pickup pattern have the most rejection
at the rear of the mic capsule, which should be pointed at the stage

monitor.

Don't cup the mic! This will defeat the directional pattern,
turning it into an omnidirectional mic.

Corporate and theatre events require specific and stable
placement of the microphone capsule. Some sound engineers argue
in favor of using omnidirectional capsules on the grounds that they
are easier to place and produce more reliable results with the
movement of the actor. My experience is that none of that matters
when the audience can't hear the actor because you can't get enough
gain.

I've done a lot of musicals and concerts with omnidirectional
head-worn microphones in the past, though, and it's always a
struggle. The performers can't hear themselves, and if the audience
starts clapping or singing along, chaos ensues. Why did I do this?
Because it was what I had available. These days I try to let directors
and event producers know way ahead of time about the limits of

working with certain equipment. If possible, I'll schedule a test so
they can hear the difference in the performance space.

Method #2 - Speaker Placement

Stage Monitors
Floor wedges should be placed on-axis and as close to the
performer's head as possible. I've heard people suggest moving the
monitor away from the performer for better gain before feedback,
but don't do that. That just creates lower sound levels at their ear
level, so you'll have to turn it up louder. Most live stages are loud
enough as it is, so anything you can do to lower the stage monitor
level will be helpful.

Have you ever seen those little Hotspot monitors? I haven't seen
them in a few years, but I love the idea. Put a small monitor on a
stand and you significantly reduce its distance to the performer.

Sometimes, because of sightline issues or stage layout, you can't
get a monitor right in front of a performer where a cardioid
microphone's off-axis point is. This happens often with drummers
and keyboard players whose instruments take up so much space and
lead vocalists who want clear sightlines. This is when you need a
hyper-cardioid or super-cardioid microphone and this is why many
live music venues have a collection of Shure SM58 (cardioid) and
Beta SM58A (supercardioid) microphones, or similar.

If you find yourself stuck with a drummer or piano player whose
stage monitor is at a 90° angle to a cardioid microphone, try
cheating the microphone out closer to 45° to get more rejection. If
an artist requests a monitor position that is less than ideal for your
microphone selection, go ahead and do it, but warn them that you
may run into feedback problems and need to reconfigure the speaker
and mic.

I've seen some pretty creative microphone and monitor

placement that allow for very high gain before feedback. If you are
working with acoustic instruments, ask the performers if they have
any tips for placement. I used to work with a cello player in
Portugal who placed the stage monitor a little behind himself so that
it wasn't pointed at his microphone but it was still aimed at his head.
It worked great.

Stage monitor placement for theatre deserves its own article, but
my number one tip is to start the conversation early. Explain your
limitations to the production team and discuss ways to best
accommodate the actors. You don't want to realize in tech rehearsals
that the actors can't hear the musicians and that the director won't
allow downstage speakers. I often lobby for small downstage
monitors straight out of the gate. I also try to make friends with the
set director and builder as quickly as possible, alerting them to the
fact that I'll probably need help hiding speakers around the stage.

FOH

Make sure your FOH speakers are covering the house and not the
stage. This means checking the speakers' off-axis angles to make
sure they are not spilling onto the stage or creating strong wall
reflections. I've heard people say that all microphones must be at
least six feet behind FOH, but I've seen it done many different ways.
Some situations call for more separation and control, others less.

Method #3 - Instrument/Source Placement

If you are working with a loud rock band and you place the lead
vocalist right in front of the drummer, guess what happens? Your
vocal mic will be full of drums and your vocalist won't be able to
hear. This happens all the time, and explains why you see the bands
on Saturday Night Live using a drum shield on that very small
stage.

Your goal is to balance every source input for the performers and
audience. Now let's talk about the most frequent offenders.

Drums
Drums are loud. Some drummers are interested in harmony and
balance, and will change their technique, use brushes, and dampen
their instruments. Those drummers are in the minority. Why? Well,
have you ever played drums? It's fun as hell to play loud, and boring
as shit to play soft, or so goes my personal experience.

If you're on tour, you'll need a rug and a drum shield. If you're
full-time at a venue, put absorption everywhere. Two of the noisiest
venues I've worked at have pulled the same trick and covered their
ceiling and walls with black semi-rigid insulation or vinyl that
screws right into the wall. Big help.

Electric Guitars
I'm a guitarist, and as such I'm fully aware of how hard it is to
hear myself without the amplifier blaring. The only way I was able

to handle this in my band was to learn to play without hearing. In
the real world, getting a guitarist's amp as close to their head as
possible will help. Put it on a chair or milk crate. Most are open-
back, so put a bunch of absorption back there.

In my interview with Larry Crane he mentions a guitarist who
built a Plexiglass shield for his amp that redirected the sound
upward at an angle so that he could play with feedback and do fancy
things with his amp without blasting the stage. Pretty smart.

I worked on a show last year where the guitarist made a shield
for his amp from case lids and jackets. This helped it not bleed into
other microphones as much.

Buford Jones is famous for doing whole tours mixing from inside
a truck outside of the venue. (He's even more famous for mixing
some band called Pink Floyd.) These were large venues where they
had little acoustic sound coming from the stage. The guitar amps

where all in dog houses off-stage and all of the performers were on
IEMs (in ear monitors). Most of us won't experience that, but it
gives you an idea of how far people will go to control sound levels
on stage. If you are worried about approaching a guitarist to discuss
changing their setup, just remember that asking them to turn down
their amp and put it on a stand is nothing compared to removing it
from the stage entirely.

Method #4 - Mix

Stage Monitor
Most performers these days are wise to the challenges of
microphone feedback on stage and will make specific requests for
their monitor mix. I've made it a practice to not add anything to a
stage monitor mix until expressly asked to, except for vocalists who
almost always need reinforcement. When musicians walk in the
door saying, "Just give me a mix of everything," they likely don't
know what they need. Smile and nod.

I've made it through entire shows without adding anything to
some performers' stage monitors because the stage layout allowed
them to hear everyone. I've also worked on shows where the band
has skipped sound check then walked on stage expecting a complete
mix. I try not to work off of assumptions and I give people only
what they need, because the lower your stage volume, the better
your FOH mix will be, and everyone will be happier.

FOH
In small to medium venues, you aren't "mixing" in the classical
sense, you are doing sound reinforcement. You are balancing the
acoustic energy in the room for a more pleasant musical experience.
From my interview with Howie Gordon:

The other thing I hear a lot about [is] guys setting the whole mix
base from the drums, and in my opinion that’s the last thing you
should do because the thing that immediately suffers is vocals. It’s
the one instrument that can’t control its own stage volume. -Howie

Gordon

And from my interview with Larry Crane:
How many times have you been blown out of the water by the

mains because you’re trying to keep up with the stage? It’s like,
“No, no, no! That’s not necessary.” You’re not building the mix up
from the kick drum at that point. You’re building the mix down from
what’s happening on the stage, and you’re filling in what’s missing,

just a little bit. -Larry Crane

If you need definition on the bass guitar, roll off the low end and
mix it in. If you are missing the melody from the keyboard, bring up
the right hand. If the guitarist is too loud then invert the polarity and
lower his volume in the house with deconstructive interference.
That's how noise cancelling headphones work.

(Just kidding! You know I'm kidding, right? If you actually try
that and it works, keep it to yourself.)

Compression
Normally, I love compressors, but they raise the noise floor and
reduce dynamic range, and therefore reduce gain before feedback. I
would really like to use compression on lapel mics during corporate
presentations, for example, but I'm often on the verge of feedback
and can't spare the gain.

Method #5 - The Holy Grail

IEMs, e-drums, synths. Done! ;)

Method #6 - Don't Give A Fuck

“These setups that we're working on, there's EQs everywhere. If
there's still feedback, it's too loud. So lower it or let it ring all night.

I don't give a fuck.” —Dimitris Sotiropoulos

I laugh every time I read this quote, but there is plenty of truth to
it. Half of what I write on Sound Design Live is about psychology.

People don't trust sound because they can't see it. That also means
they don't trust you because they can't see what you're doing.
Letting the monitor feedback for a second before you bring it down
communicates to the artist that it has reached it's maximum level
and that you are turning it down.

Q: But you do use EQ, right?
A: Um, yeah, most of time. At least to attenuate some low end.

#ObligatoryBonus - EQ

This is your last tool in the war on feedback. Use high-pass
filters to remove the rumble from guitars and the proximity effect
from vocals. Use narrow-band filters on a parametric EQ to
surgically remove problem frequencies. Although it's your last step,
it's also necessary. Temperature, humidity, and performance
changes throughout the night will require compensation.

I recently worked with a sound engineer who would cut the low

end from all of his vocals up to 200Hz in the stage mix. That's a lot!
But it worked. A few years ago I worked on an outdoor event where
everything would be balanced during the afternoon sound check,
then explode into feedback at night because of environmental
changes.

So I think we can agree that some amount of EQ is necessary,
but watch out for assuming too much. There is a process that we
sound engineers call "ringing out the monitors" that often takes
place before any artists have arrived. We use this process to lessen
the amount of time we will need to chase feedback during sound
check. I gotta tell you that over years of working on live events I do
this less and less. Why? Because if you do it before sound check
then you are making a lot of assumptions about the sound that can
all be ruined by changing a mic or its placement. You're also
making changes to the speakers' performance and sound quality
without due cause. A better technique is to test for feedback, make
note of those frequencies, but hold out on makes changes until you