When it comes to inputs, particularly those that are needed to operate equipment like microphones.
It is always important to have enough information so you can make your equipment usable with your inputs.
This post will address microphones and Auxiliary or Aux inputs because this is a common topic among new audio engineers and technicians.
With that said, one of the frequently asked questions with regard to this is “Can I put a microphone in an Aux input?”
Yes you can plug or put your microphone into an Aux input but In order for you to use your microphone with an Aux input in most cases, you’ll need to use a pre-amplifier because Auxiliary inputs by design, work with amplified signals.
Therefore your microphone needs a pre-amplifier to ensure that it work optimally because typically microphones don’t put out enough voltage.
If you do plug in your microphone into an Aux input with out a pre-amplifier you’ll most likely have a lot of noise in the signal or you’ll simply have a weak signal.
However, many computers especially those with built-in “Realtek High Definition Audio, usually have dual purpose input jacks and drivers like “Realtek HD Audio Manager that asks you whether you’re plugging in a microphone or a line-level device… if you have that or something similar you’re good to go with almost any microphone that has a 3.5mm AUX style plug.
In order to have a firm understanding of inputs, you need to get good knowledge of different signals.
It’s important to understand the different types of audio levels so it helps us understand out equipment better.
Therefore this part of the post will discuss the main types of audio levels that one will obviously encounter in audio production.
A microphone basically captures sound by simply converting pressure changes in the air into electrical currents in a wire.
The electrical currents created by these pressure changes are very subtle that’s why microphones are said to have a weak signal.
It is for this reasons that we utilize a microphone pre-amplifier – to amplify and boost the signal to a more stronger and usable level.
A microphone pre-amp is how you convert a mic level signal into line level signal.
All a pre-amplifier does is, it takes in a microphone level signal, amplifies it, and outputs a line level signal. This is controlled by the gain knob on your mixing console, audio interface, or outboard mic pre-amp.
In order to have a basic understanding of Instrument level signals, let’s take the basic example of guitars.
Simply, the pickups of an electric guitar convert the vibrations of the strings into electrical currents.
Similar to those signals from a microphone, the electrical currents from a guitar pickup are very weak which basically makes the audio signal weak.
In this case a pre-amp can also be used to boost or strengthen instrument level signals to line level.
Line level is an audio level that is optimized for use with professional audio equipment, such as mixing consoles, outboard effects, and amplifiers.
The fact is that Line level is adequate for sending signals between devices, but it is not strong enough to power a speaker.
In order to power a speaker, you need an amplified line level signal.
In order to amplify your line level signal, you can use a power amplifier.
A power amplifier simply takes in a line level signal, amplifies and boosts it, and outputs a speaker level signal that is strong enough to power a speaker.
Now that we’ve discussed the various audio levels that you need to know in order to understand equipment better let’s get into the two most important connection types namely the Balanced Connection and Unbalanced connections.
A balanced connection is sometimes called a symmetrical connection and it prevents unwanted noise and hum.
Balanced connections are usually the connection of choice for most when large distances need to be bridged, especially when carrying weak signals like those of microphones.
For a balanced connection, both linked devices need to have a balanced socket to ensure that the emitted signal is duplicated: one of those signals is sent normally and the other copy is sent with reversed polarity.
The device at the other is responsible for receiving both the signals separately, then re-reverses the polarity of the copied signal, then combines the two signals.
The point of this “switching-trick” is that the original signal becomes becomes boosted so its louder and that any noise that is picked up while travelling along the two wires in the cable disappears.
An unbalanced cable consists of two connectors with two conductors each and they are connected by two wires within the cable— comprising of a signal wire and a ground wire.
In most cases it is easy to identify a cable designed to carry an unbalanced signal by its connectors: because each wire has to terminate at the connector with its own unique contact point, an unbalanced cable requires only two conductors at the connector.
A standard TS (or “tip-sleeve”) guitar cable is the unbalanced cable you’ll run into in most stage work. Standard RCA cables used for many AV components are also unbalanced cables.
Microphones are microphone level equipment which means they typically produce a weak signal. Therefore in order to use them or plug them into an aux input. A pre-amplifier should be used because Aux Inputs work optimally with amplified signals.