2019-07-01_Computer_Music

Microphones

Microphonesturnsoundwavesinto

electricalsignals,whichcanthenbe

recorded.It’sa simpleenoughconcept

basedonsomeprettyfundamentalphysics,

buttherearevariationsinhowtheywork

andwhatthey‘hear’.

Eachtypeofmicrophonehasitsown

particular‘polar’or‘pickup’pattern.An

omnidirectionalmicpicksupeverything

aroundit reasonablyequally,whilea

cardioiddirectionalmicpicksupthesignal

infrontofit morethanthatatthesidesor

rear.Anothercommontypeisthe‘figure-8’,

whichpicksupthefrontandrearequally

butrejectsthesides;whilethe

hypercardioidprovidesa narrower

directionalpattern.Somemicsevenhave

multi-patterncapabilities,allowingyouto

choosefromtwoormorepatterns.It’s

importanttounderstandwhatany

givenmicisactuallyhearing,soyou

canchooseonethatsuitsthetask

athandandthespaceyou’rein.

Themostubiquitoustypeofmic

isthecardioid,becauseit’s

directional,sobypointingit atyour

source,you’llhearthatmorethan

everythingelse–

particularlyuseful

whenyouwantto

tryandisolate

whatyou’re

recordingfrom

othersounds.A

cardioidmicdoes

stillpickupsound

frombehindit and

tothesides– it’s

justlesssensitive

there.It also

exhibitssomething

calledthe

proximityeffect,

creatingan

obviousbassboost

asyougetcloserto

thecapsule.Allthis

addsuptoa

designthat’s

functionally

usefulbutnot

completely

transparentinitsbehaviour.In

largerspaceswithgoodacoustics,

anomnidirectionalmicwilldelivera

morenaturalsound;theyalsowork

wellusedasspacedpairstorecord

instereo.

Theotherimportant

considerationwithanymicisthe

wayinwhichit converts

soundwavesintoelectricalsignals.

Therearethreemaintypes:

dynamic,condenserandribbon.

Dynamicmiccapsulesincorporatea

movingcoilandmagnet.They’re

robust,reliable,affordableand

typicallyusedforlivevocals,kick

drums,tomsandother‘high-impact’

sources.A condensermiccapsuleis

a capacitor,soit requiressometype

ofpower(often48Vphantompower

viathemiccable)andislessrobust,but

moresensitiveandaccuratethana

dynamic.Condensersarewellsuitedto

studiouseandpopularforrecordingvocals,

guitars,pianosandroomsignals.

Finally,theribbonmicemploysa thin

metalfoilor‘ribbon’anda magnetinits

pickup.Thisisveryfragile,andhasa low

outputleveland– bydesign– a figure-8

pickuppattern,forsmooth,naturalresults.

It’salsoexcellentathandlingbright,

complexsoundssuchascymbalsandbrass.

Accessories

It’swisetoallocatemostofyourbudgetto

decentmicrophones,buttherearea few

otherextrasthatyou’llneed,too.

Micstandscanbeacquiredreasonably

cheaplyorsecondhand,butaimforthe

bestqualityyoucanafford,ascheaper

standsarehardertoadjustandtighten,and

maydrooportoppleoverwithheaviermics.

Standsalsovaryinheight,andit’s

practicallyimpossibletomicupa snare

drumwitha full-sizedstand,asit getsinthe

way– sobepreparedfortheinstruments

you’rerecording.

Newmicsusuallyincludea clip,cradleor

bothtoattachthemictothestand.The

cradleisexcellentforinsulatingthemic

fromvibration,andsoshouldbeusedif

possible,butmaynotbeeasytopositionfor

certaininstruments.Universalclipsare

availableandoftencomeinhandy.

Forrecordingvocalswitha cardioid

condenser,someformofpopshieldisa

must.If you’restrappedforcash,youcan

makeonefroma coathangeranda pairof

tights,buta properoneiseasiertosetup.

Finally,makesureyouhaveenoughlong

miccablestogetthesignalsfromthe

instrumentsthatyou’rerecordingwithto

yourinterface.

“Mic technology is

simple enough, but

there are variations

in how they work”

Live and direct

Recording an electric guitar (or bass) straight
into the audio interface, rather than via an
amplifier, is called a DI (direct injection)
connection, and it will get you a nice clean
signal that you can process later in your DAW.
However, you need some way of handling the
very high impedance output of the
instrument. Historically, you would use a DI
box for this, and these are still useful when you
want to record both the amplifier output and
DI, as they also split the signal. To record just a
DI, however, look out for a high impedance (Hi-
Z) input on your audio interface.

Shure’s SM58
(above) is a popular
dynamic mic, while
Royer’s R-10 (right)
is a smooth-
sounding ribbon
mic – ideal for
recording guitars

Sontronics’ STC-3X:

a multi-pattern,

large-diaphragm

condenser mic

Mackie’s Onyx Producer 2.2 audio interface features a Hi-Z input for recording DI signals straight into your DAW

July 2019 / COMPUTER MUSIC / 25

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