How to choose a microphone for all occasions | Articles | Audio and video equipment

To learn how to choose a micro­phone, you first need to under­stand why you need it — record videos, sing on stage or host pod­casts. Here we will talk about what types of micro­phones can be found and how they dif­fer.

What are microphones

• Stu­dio — these micro­phones are designed for record­ing sound in the stu­dio or at home. They are both large and small. The lat­ter include the AKG P220. It is on such micro­phones that audio tracks for films and music albums are writ­ten. Sim­i­lar­ly, they are used by blog­gers and stream­ers. Most often they are con­nect­ed via a USB cable or a 3.5 mm jack.
• Con­cert — This type of micro­phone is used dur­ing live per­for­mances. Micro­phones are both wired and wire­less, are includ­ed in the ampli­fi­er and often have a han­dle. These micro­phones are also often mount­ed on a stand.
• Reporter — this type includes both small lava­lier micro­phones and boom micro­phones that are attached to a record­ing device. A good exam­ple of such a micro­phone is the Ray­lab Rec. DH LavMic, which is also built for blog­ging and out­door work.
• Head­sets are built-in micro­phones that are com­bined with head­phones, such as Apple Air­Pods.

A con­denser micro­phone is suit­able for film­ing in good weath­er. Pho­to: raylab.ru

Operating principle

There are sev­er­al ways in which micro­phones work:

• dynam­ic;
• con­denser;
• car­bon­ic;
• optoa­coustic;
• piezo­elec­tric.

But only the first two are com­mon, since the rest are of poor record­ing qual­i­ty.

Dynam­ic micro­phones include a small elec­tric gen­er­a­tor, which con­sists of a diaphragm — a spe­cial plate, a voice coil and mag­nets. Sound caus­es the diaphragm and coil to oscil­late, and the oscil­la­tion caus­es an alter­nat­ing cur­rent. This type of micro­phones are reli­able, and the design allows them to work in dif­fer­ent con­di­tions. For exam­ple, the Audio-Tech­ni­ca ATR-2100-USB dynam­ic micro­phone can be used for out­door press con­fer­ences.

Dynam­ic micro­phones pick up loud and strong sounds and it is almost impos­si­ble to over­load them. Choose them for live per­for­mances and con­certs.

Con­denser micro­phones work with a plate that vibrates with sound. It caus­es the charge on the capac­i­tor to fluc­tu­ate, which leads to sound record­ing. Such micro­phones are small­er in weight and size, and their sound is more accu­rate than that of a dynam­ic one. Con­denser micro­phones require green­house con­di­tions to oper­ate, and the range of processed fre­quen­cies is low­er than that of dynam­ic ones. Also, the elec­tron­ics built into the micro­phone adds noise when record­ing, which is espe­cial­ly notice­able in cheap mod­els.

Choose them for use in stu­dios, con­cert halls and the­aters.

Micro­phone with on-cam­era mount. raylab.com

Orientation

Anoth­er impor­tant point is the direc­tion­al­i­ty of the micro­phone. It dis­plays the sen­si­tiv­i­ty of the micro­phone, depend­ing on the loca­tion of the sound source.

— Uni­di­rec­tion­al micro­phones are most sen­si­tive to sound from one direc­tion. They most often have a car­dioid radi­a­tion pat­tern, shaped like a heart. The angle of oper­a­tion of such a micro­phone is about 130 °.

• Micro­phone with car­dioid direc­tiv­i­ty, this is Ray­lab Rec. Min­iM­ic, it records sound from the front, drown­ing out ambi­ent noise as much as pos­si­ble. This gives a clear voice with­out dis­tract­ing sounds and is suit­able for reportage blogs.
• The AKG D7 S is a super-car­dioid micro­phone that picks up sound well from the front and part of the back, but not from the sides. Suit­able for record­ing com­ments and inter­views in seg­ments where the voice of the pre­sen­ter is not impor­tant.
• The hyper­car­dioid pat­tern in the Audio Tech­ni­ca PRO25AX micro­phone func­tions exact­ly the oppo­site: the sound cap­tures weak­er in front, stronger in the back. Suit­able for those who shoot vlogs.

- Bi-direc­tion­al micro­phones pick up sound equal­ly well from the front and back and do not pick up sound from the sides. Their dia­gram is called “eight”. A micro­phone such as the Audio-Tech­ni­ca PRO24CMF is a good choice for inter­views.

- The omni­di­rec­tion­al micro­phone picks up the sound around in the same way accord­ing to the spher­i­cal dia­gram. Suit­able for record­ing nature videos and video tours. For exam­ple, lava­lier omni­di­rec­tion­al Boya BY-F8OD.

Sensitivity and frequencies

Micro­phone sen­si­tiv­i­ty is report­ed in deci­bels (dB) or mil­li­volts per Pas­cal (mV/Pa). Neg­a­tive and low deci­bel read­ings mean less sen­si­tiv­i­ty. The low mV/Pa also means that the sen­si­tiv­i­ty is low.

But the sen­si­tiv­i­ty is not equal to the qual­i­ty of the record­ing, it all depends on what and where you plan to record. For exam­ple, at a cham­ber con­cert or in a stu­dio inter­view, it is bet­ter to use high sen­si­tiv­i­ty, and on a noisy street — low.

Sound pres­sure lev­els, or SPL, are also mea­sured in deci­bels and reflect the max­i­mum sound inten­si­ty that a micro­phone can pick up. The aver­age val­ue is 100 dB, the high val­ue is 130 dB.

From the range of repro­ducible fre­quen­cies depends on how nat­ur­al the sound will be on the record­ing. Vocals and musi­cal instru­ments require a range of 40–50 Hz to 15,000 Hz, although 20–30 Hz is rec­om­mend­ed for bass instru­ments. 80–10,000 Hz is enough to record speech. And for these pur­pos­es, the Ray­lab RecMic SH LavMic lava­lier wired micro­phone, whose range is 20–20,000 Hz, is per­fect. This is more than the aver­age rec­om­mend­ed, and means that the micro­phone will not be over­loaded with loud sounds. The voice will remain clear even if a car pass­es by or a heli­copter flies in the sky.

Micro­phones with high sen­si­tiv­i­ty are suit­able for stu­dios. Pho­to: rode.com

Microphone connectors

To con­nect a micro­phone to an ampli­fi­er or record­ing device, sev­er­al types of con­nec­tors are used.

• Jack (jack) is of sev­er­al types: stan­dard 6.3 mm, mini-jack 3.5 mm and micro-jack 2.5 mm. The stan­dard one is used in some types of pro­fes­sion­al musi­cal equip­ment, the mini-jack is used for com­put­ers and user devices (speak­ers, play­ers, smart­phones), and the micro one is used for portable equip­ment (labels and some types of head­phones).
• XLR is a pro­fes­sion­al con­nec­tor found on live micro­phones and is used to con­nect to an ampli­fi­er.
• The USB con­nec­tor is used for home appli­ances and con­nec­tion to a com­put­er.
• Adapters can be used with con­nec­tors, which are often includ­ed in the kit.

Con­ve­nient con­nec­tion via 3.5mm port. Pho­to: raylab.ru

Extra options

• Signal/noise is a mea­sure of dis­tor­tion, the high­er the val­ue, the less the sound is dis­tort­ed. The stan­dard val­ue is 65 dB, in pro­fes­sion­al tech­nol­o­gy the val­ue can exceed 70 dB. But mod­ern micro­phones some­times offer extend­ed per­for­mance, such as the Ray­lab Rec. Min­iM­ic is 76 dB, which is rare in com­pact micro­phones. This means that there will be less dis­tor­tion when record­ing from such a device.
• Range or cable length is impor­tant depend­ing on the pur­pose of the micro­phones. For exam­ple, the Shure SM57-LCE can oper­ate wire­less­ly up to 100 meters, while the bud­get Thom­son M135 is lim­it­ed to 3.5 meters of wire.
• The body mate­r­i­al is usu­al­ly met­al or plas­tic. Met­al is heav­ier, but more reli­able. Plas­tic is lighter, but can break if dropped or bumped.
• Acces­sories may be includ­ed or sold sep­a­rate­ly. For reporter mod­els, this is a wind pro­tec­tion, which can be foam and fur. Fur pro­tec­tion is designed for strong gusts of wind and loud exter­nal noise. Foam rub­ber is effec­tive when record­ing indoors. It is best if the kit includes both types of tips, like Ray­lab Rec. D.H. LavMic. Thanks to this, you can record dif­fer­ent seg­ments by sim­ply chang­ing the wind­shield.

Lava­lier micro­phones often also come with a clip for attach­ment. For stu­dio and live devices, you can addi­tion­al­ly pur­chase table fil­ters that do not let in extra­ne­ous noise, wire­less pow­er sup­plies, ampli­fiers and racks.

The sound pass­es through the foam fil­ter and is record­ed with­out extra­ne­ous noise. Pho­to: raylab.ru

Outcome

Always choose a micro­phone that suits your pur­pose.

For vlog­ging and inter­views in fine weath­er or in the stu­dio, a lava­lier car­dioid con­denser micro­phone such as the Ray­lab Rec. D.H. LavMic.

If you are record­ing out­doors in bad weath­er, a dynam­ic lava­lier micro­phone such as the Ulanzi AriM­ic is a bet­ter choice.

For record­ing solo pod­casts and streams, get a uni­di­rec­tion­al desk­top micro­phone such as the RODE NTUSB.

And if you record vocals, then you should get a car­dioid stu­dio micro­phone with a fil­ter, like the BOYA BY-M800.

And of course, nev­er for­get that price is not an indi­ca­tor of qual­i­ty.