Is something sounding off when recording? It could be the gain on your microphone.
Many voice actors, singers, producers, and just anyone who comes into contact with a microphone may find that they are having issues with their microphone and may not know what it is or how to fix the issue.
We will explain what a gain is on a microphone, how it may be affecting you, and how to resolve the issue.
No one wants to have weird audio recordings due to weak signal strength. However, if it does happen you will know what the problem is and fix it in record time.
What Is A Gain?
The amplitude of a microphone signal is increased by microphone gain. Gain increases signal power from mic level to line level, enabling professional audio equipment to recognize the microphone signal.
The first circuits a signal runs through following the microphone output are mic preamps, which regulate gain.
To look at in more detail you need to understand the basic audio signals.
Analog audio signals on a microphone are digital audio signals. Measured in dBu or dBV, both are measurements of decibels in relation to voltage:
- 0 dBu= 0.775 volts
- 0 dBV= 1 volt
Although they can occasionally emit digital signals, microphones are by nature analog devices. Analog signals frequently apply gain. In essence, the digital gain is basically a multiplication of the digitized value that reduces resolution.
The ability of an amplifier to boost a signal’s amplitude from the amp input to the amp output is measured as gain in electronics. An amplifier “applies” gain to an input signal so that it will be stronger at the amplifier’s output.
Gain adds energy to the signal. This is done by the energy being converted from an external source of power to the microphone. Whether the power is from a wall plug, batteries, or other power sources.
Types Of Microphone Gain
There are 2 possible gain stages for a microphone signal to travel through when in use:
Active Preamplifier Within The Mic
Active preamplifiers are housed inside the microphone body of condenser mics and other active microphones.
The voltage and impedance of the audio signal generated by a microphone capsule are frequently too low and too high, respectively, to be of any value.
Typically an active amplifier is placed in line with the capsule to increase the voltage to a more effective level.
This will also decrease the signal impedance. Having a lower impedance will allow the signal to work its way through the cable without being massively interfered with.
The gain achieved with a preamplifier within the mic is generally fixed and cannot be altered to suit your needs.
A lot of active microphones have attenuation pad switches, which reduce the output audio signal’s loudness before it reaches the amplifier.
These pads are there to stop overloading the active circuitry or amplifier and the resulting distortion of the signal.
The gain provided by an active amplifier is often not strong enough to amplify active microphone output signals and bring them to line level.
Active Preamplifiers In USB/ Digital Microphones
USB and digital microphones that work to output digital audio are designed with built-in analog to digital converters (ADC’s).
They will also have a microphone preamplifier fitted before the ACD component. This allows the preamplifier to be adjustable when it comes to the gain it provides.
This means that you can adjust the microphone’s audio signal to the correct line level before the signal is converted to digital.
Outsourced Microphone Preamplifier
When dealing with gain coming from a separate preamplifier, it is important to remember that the gain is provided to the signal at the mic input of a preamp.
It is important the microphone is not plugged into a line input. As line inputs require a stronger signal than mic levels, there will not be enough gain to boost the microphone signal and make it high-quality.
Analog and digital audio recording and mixing are almost always done at line level.
As a result, it’s crucial to get analog audio to line level with amplification, and suitable ADCs that can convert line-level analog signals into digital signals are also required.
Impact Of Gain On Mic Signals
As covered above, microphones generally work from analog signals which are then converted into digital signals.
The gain of a microwave is used to boost the strength of the signal to help reach line level and create a smoother sound.
The amount of gain required for a microphone will depend on 2 things:
- The closeness of the sound source and the volume of the source the mic is capturing i.e your voice.
- The sensitivity of the mic. This is the signal output against the sound pressure level.
For example, passive microphones are less sensitive than active microphones, which include condenser microphones (moving-coil dynamics, for example).
In other words, a condenser mic will require less preamp gain than a dynamic mic to attain line-level signal intensity, assuming all else is equal.
This demonstrates how the sensitivity can impact the microphone gain.
An example of how the proximity and volume of the sound source can impact the microphone gain imagine: To attain line level signal strength, a microphone placed close to a kick drum would require less gain than a similar mic placed farther away from the kick drum.
Additionally, the kick drum mic would need less gain than the identical microphone positioned in front of a voiceover performer.
Essentially the main objective is to amplify the signal to a secure line level and make it equal in signal strength to the other equipment around the area.
If you are wondering why your microphone audio sounds off or weak, it could be that the signal is not strong enough from the microphone to the power source. That’s where a microphone gain comes in.
You want the microphone gain to help the signals reach a nominal line level to ensure the signals of other instruments do not interfere with each other.
Try using a microphone gain or a microphone with a fitted preamplifier and discover a whole new range of high-quality sounds.