Hardware & signal path
Mic input
A mic input takes the very low signal a microphone produces and amplifies it to line level, with its own gain, usually its own two-band EQ, and on club mixers a talkover control that ducks the music while someone speaks.
In practice
Gain down when the mic is not in your hand. It is the only input that can hear the room, and it will.
Set mic gain against your speaking voice at the distance you will actually hold it, which is closer than most people assume — an inch or two, off-axis. Roll the low EQ down to remove the proximity boom, leave the high alone unless it is dull, and use talkover rather than pulling the music down by hand. If a promoter wants to make an announcement, hand them the mic with the gain already set rather than letting them find it themselves.
1–2 in
Working distance
Low cut
The EQ move that fixes boom
Off
Where the gain lives by default
Where these come from: Standard handheld microphone technique and club-mixer mic EQ practice — not catalog figures. For what we can measure, see the loop that causes the howl.
Why it matters
A microphone is the one input that can embarrass you in front of a full room, because it is live the moment the gain is up and it does not care whether you meant it. Every DJ who has left a mic open has learned this the same way, and it is why the first thing to do on an unfamiliar mixer is find the mic off switch.
It is also the input most likely to cause feedback, because unlike every other source it is in the same room as the speakers. The loop that produces the howl runs speaker to microphone to speaker, and the only inputs it can start on are these.
Frequently asked
Why does the mic feed back?+
Because it can hear a speaker that is playing what it just heard. Move out of the monitor’s throw, drop the gain, and cut the frequency that is ringing rather than turning everything down.
Does the mic input have phantom power?+
Club DJ mixers usually do not, so a condenser microphone will not work on one. Dynamic microphones need nothing and are what venues supply for exactly that reason.
Should I use talkover or just pull the music down?+
Talkover, because it ducks by a fixed amount and restores instantly. Doing it by hand means the music dips by a different amount every time and comes back late.
Related terms
Talkover
Talkover automatically reduces the music whenever the microphone channel detects speech, then restores it when you stop. On club mixers the amount of the dip is adjustable, typically between about 6 and 24 decibels.
Feedback
Feedback is a loop: a microphone hears a speaker playing what the microphone just heard, and the loop builds until one frequency dominates and howls. It needs an open mic and a speaker the mic can hear.
Phantom power
Phantom power is 48 volts sent up a balanced microphone cable by a mixer or interface to power a condenser microphone. It is switched on at the input, and most DJ equipment does not provide it.
Aux input
An aux input is a spare line-level input for a source that is not a deck: a phone, a laptop, a sampler, a guest’s interface. It usually has less control than a full channel.
Explore: Reading the room · Talkover · Feedback · All DJ terms