Polarity switches are small buttons or switches on mic preamps and mixers that can reverse the polarity of an audio signal. They are also sometimes called phase switches, although polarity and phase are not exactly the same thing. In this article, you will learn what polarity switches do, why they are useful, and how to use them effectively in your audio recording projects.
Polarity is the direction of the electrical current in an audio signal. It can be positive or negative, and it affects the movement of the speaker cone or the microphone diaphragm. Phase is the relationship between two or more audio signals that have the same frequency and waveform. It can be "in phase," meaning the signals are aligned and reinforce each other, or "out of phase," meaning they are opposite and cancel each other out. Phase can vary depending on the distance, angle, and timing of the sound sources and the microphones.
Glad you mentioned this. Many people conflate polarity with phase. They are two very different things, and can have two very different solutions.
Polarity switches can help you avoid or correct phase issues that can degrade the quality and clarity of your audio recordings. Phase issues can occur when you use multiple microphones to capture the same sound source, such as a drum kit, a guitar amp, or a vocal ensemble. They can also occur when you combine signals from different sources, such as direct inputs and microphones, or when you process signals with effects, such as delays and filters. By flipping the polarity of one or more signals, you can align them better and improve the coherence and balance of your mix.
Check the polarity switches on your mic preamps before you start recording. Listen to the signals in solo and in combination and compare the sound with and without the polarity switch engaged. You can also use a phase meter or a spectrum analyzer to visually monitor the phase relationship between the signals. Look for the polarity setting that gives you the most natural and full sound, and avoid the ones that cause thinness, comb filtering, or loss of low frequencies.
When mixing, use the polarity switch as a creative tool to enhance or alter the sound of individual tracks or groups. For example, you can use the polarity switch to create contrast or tension between different elements of your mix, such as the kick drum and the bass or the lead vocal and the backing vocals. Also, utilize the polarity switch to create space or depth in your mix by flipping the polarity of some effects sends or returns, such as reverbs or delays.
The “Polarity” switch was intended for mis-wired balanced cables and other unintended things that happen during a $$$ session.
When working on audio recording projects, experiment with different polarity combinations to get subtle or dramatic changes in sound. Use your ears and trust your judgment rather than relying on visual indicators or rules of thumb. Be mindful of the potential consequences flipping the polarity of a signal can have, such as changing the timbre, dynamics, or stereo image. Polarity switches should be used sparingly and selectively to avoid confusion or inconsistency in your mix.
I use it all the time on WA12 MKll, recording acoustic guitar left/ right and on bass as well as on Vocal sometimes, depending on what I want to achieve but it is a great way to change the sound on the whole recording session using your old microphones that will sound very different by pressing the polarity switch;) Also when you use only one microphone it is a great way to combat a phase cancellation in your recordings.