Using The Control Room for Feedback
by Jon Chappell
||Whether you have the luxury of miking your amp or are relegated to going direct
via a speaker simulator, you still should know about room simulation within effects
units. A room simulator is a program that's not used as a reverb effect per se,
but as an ambient enhancement. If you've ever used a drum machine, you may have
noticed that the samples (drum sounds) are not completely dead sounding. They
have a little bit of "air." You can then add a long reverb (large room,
hall) to your final mix. But the room sound is still heard as part of the original
sample. That same approach should be used in setting up a basic guitar sound.
N.S. "Buck" Brundage of ART, and designer of the Power Plant preamp,
says that you should not scrimp on the two front-end steps of close miking and
room simulation. "Spend as much time as possible moving the mike around to
find the sweet spot. This is absolutely critical. Then, if you have a room simulator
in your effects processor, tweak that until it sounds right. There are many units
that will do this, but I use ART's DRX 2100 SE, which uses a system called AES-acoustic
environment simulation. Here, I can control room size, frequency response, mic
position, and objects in the room-such as wood plus rug, pews with people, etc."
It should be noted that room simulation can be done with a direct signal as well
a close-miked one. But however you get your basic sound, the EQ and "effects"
(long reverb, delay, panning, chorus, etc.) should be added last. Taking care
in these early steps will pay off in great sound and tonal education. After enduring
all the leg work of positioning your mics, you're probably ready for a treat.
Here's a great trick that will simulate what happens when you stand in front of
your cranked amp rather than two rooms down the hall "behind the glass."
Of course, we're talking about feedback. Buck Brundage taught me this one, and
I use it shamelessly. To do it you need an aux out of your preamp or mixer. What
we'll do is set up a separate line out with your guitar signal that will be used
solely to generate controlled, user-specified feedback. Here's how we do it. Let's
take the case of a mixer. Run an aux send (all mixers have at least two of these
per channel, so select the one not being used for reverb or other global effects)
from your mixer's guitar channel into a smaller amp that you keep in the control
room with you. It's best to use a small 12" combo with a decent clean sound.
The idea is to sit in the control room and use the small amp to generate feedback
at desired spots during your solos. Feedback works when certain frequencies from
the speaker oscillate the strings into producing more sound which in turn creates
more frequencies, ad infinitum, and thus the phenomenon known as feedback.
We'll be using the control-room amp to act as our "string exciter."
Remember, we're not actually going to be hearing this amp, we're just using it
to move the guitar strings. We're looking only for some octave feedback and perhaps
some additional sustain. Set the amp controls with a little high cut, boosted
mids, and a little added low end. Put the amp on a chair or stool so that you
can face your guitar into it when you want feedback. The position of the amp will
vary according to the type of guitar you're using, the pickup sensitivity, how
loud the control room monitors are, etc. There are two ways to initiate feedback:
either by turning the face of the guitar into the pickups at the appropriate time,
or having someone actually turn up the amps volume in time with the music when
the feedback point comes. This way an assistant "plays" the amp as you
play the guitar. Again, no level change will be apparent in the final track, because
this amp is not being recorded; it's merely acting as a string vibrator. You should
practice with the track and your assistant, until you get the right performance
down as well as establishing the right settings on the feedback-inducing amp.
Even a subtle application of this works wonders. As Buck points out: "There's
a lot of magic that happens in that fringe area of feedback. Even a little sustain
as the result of feedback will not only enhance a sound but will inspire a guitarist's
performance." Using feedback off of an amp is better than using the control-room
monitors for two reasons: 1) you won't have to vary the monitor levels of the
entire track just to induce feedback, and 2) the guitar won't get "confused"
by the complete mix. Using the amp will allow the pickups to listen only to their
own frequencies. Practice manipulating the frequencies that produce basic sustain
and simple octave feedback before going totally "Steve Vai" with this
trick. But once you're comfortable with that, by all means, get experimental.
Go to the production page of Buck’s web site to view a list of the artist’s
he has worked with.. www.couchcreativeservices.com
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||Miking Amps and Cabinets - Part I by Jon Chappell
||I'll open this month's column with a little historical quiz: One famous guitarist
went to hear another famous guitarist perform, and witnessed a less than successful
evening of synth guitar execution. The famous guitarist in the audience later
said of the famous guitarist onstage, "He spent all night trying to make
a $2,000 guitar sound like a $300 one." Who uttered this famous line, and
to whom was he referring? Write or e-mail me the answer and a randomly drawn entry
with the correct answer will win one of the following: 1) an all-expense-paid
trip to Hawaii for two; 2) a year's supply of Vaseline; or 3) a Guitar Magazine
guitar strap. (Best of all, I'll print your name in next month's column.)
The point of this trivia contest is not to deplete Guitar Magazine's warehouse
of useless junk like guitar straps, but to make the point that the simplest solutions
are often the best. Case in point: I've seen guitarists use thousand-dollar effects
processors, rack-mounted amp simulators, and parametric EQ wizardry to try to
emulate a basic guitar sound. After all that, it still sounds pinched and largely
unconvincing. The irony is, expensive signal processors have to jump through hoops
just to capture the sound of a mid-priced combo and a cheap micropho ne. If you've
wondered why you can't hook your pedalboard up to your Portastudio and get a good
sound, it may reassure you to know that it doesn't get much better when you use
higher-priced pedalboards. But with even a modest amp and inexpensive dynamic
m ic, you can get realistic and exciting guitar sounds. And best of all there's
no magic, only a couple of well-established guidelines.
The mic of choice for years for miking speakers was (and still is, though others
work just as well) the Shure SM -57. This is a dynamic (as opposed to condenser)
microphone, with a large diaphragm that can withstand high sound pressure levels.
In other words, this mic is happiest being slammed by a loudspeaker at close range
with low and midrange frequencies. Placin g the mic about 1-2 inches away from
the grille cloth is yields optimum results, and positioning it slightly off center
(looking at the edge of the bull's eye, not straight on) results in a fatter sound.
Nowadays there are dozens of mics on the market tha t conform to the high-spl,
large-diaphragm spec, and some are even optimized for guitar cabinets (the SM-57
was originally designed as a vocal mic).
N.S. "Buck" Brundage, designer of ART's Power Plant studio guitar preamp,
has contributed his technology and production talents to such artists as Al Di
Meola, Fate's Warning, Steve Morse, and keyboardist/producer Jan Hammer (Mahavishnu,
Miami Vice). He offers this advice when miking cabs in the studio: "A great
guitar sound starts by getting your sou nd happening in the room. Once the amp
is tweaked to perfection, proper miking technique is essential in getting your
sound to the other side of the glass. Start with a boom stand, so you can easily
adjust the vertical and horizontal axis of the mic(s). I prefer starting the miking
process with an Shure SM-57.
"After you set up the amp so that
it sounds good in the room, put on headphones to hear what the mic is picking
up. Sometimes I'll replace a guitar with a noise generator and have the enginee
r send white noise to my headphones via a monitor send so I can move the microphone
until I find the 'sweet spot' on that particular speaker. I often like to use
two mics, an SM-57 and a Sennheiser 421, because each will pick up some quality
the other misses. If you have the budget, you can put a high-quality condenser
mic, like a Neumann U-87 or AKG 414, about waist high, on axis, several feet back
from the amp. This will help capture ambient or room sounds. But less expensive
mics work great on guitar s peakers for two reasons: one, they don't pick up every
little high-end detail, like rattle and noise, and two, they won't be so easily
overpowered like more-expensive ones that have sensitive diaphragms."
Generally, Brundage advises, a 57 (and mics like it) will provide definition and
the 421 (and its ilk) will create body. Virtually all the sound should come from
the mics. If you have to make excessive EQ corrections, the miking is probably
at fault. "If you have to push or pull any part of the EQ past 6 dB, you
should re-position the mics, or even switch mics," advises Brundage. "Get
it with the amp and the mics before going to the board. The danger with board
EQ is that you risk adding or subtracting something that's not even there. If,
or examp le you try to boost the highs and there are no highs in that range, you'll
just add noise."
If you're miking a 4x12 cabinet instead of a combo, your options are even more
varied. "When you have four speakers to choose from, you can put one mic
on o ne speaker in the cab, and the second mic on another. This increases you
tonal possibilities," says Brundage. "Also, you can set up your room
sound in the studio, then take the head with you into the control room for further
tweaking on the head. This way an assistant makes the mic adjustments while you
sit in the control room, listening to the results over the studio monitors. Once
you've achieved your sound, any minor tweaks can be accomplished at the board
using the individual channel EQ. It's at that point that you could add and monitor
effects such as chorus, delay and reverb. Effects can be monitored but should
not printed. As a final note, there are many proven methods for miking and recording
guitars, but there are no 'rules.' Do what works for th e track and you can't
Next month: effects, room and speaker simulators, and stupid tricks that will
make you sound like a hero.
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