On our subwoofers, you can adjust the phase and also invert the signal (polarity). Both functions are related but different concepts.
Phase
Phase refers to the alignment of the subwoofer’s sound wave with the sound waves from the main speakers. When the subwoofer’s sound wave aligns well with the main speakers, they reinforce each other, resulting in a fuller, more cohesive sound. Adjusting the phase allows you to synchronize the subwoofer’s output with the main speakers. Typically, this is done by adjusting the timing of the subwoofer’s sound wave relative to the main speakers’ sound wave. Phase adjustment is represented in degrees, where you can choose in increments from 0° to 180°.
This adjustment only takes place around the set crossover frequency!
Signal Invert
Signal invert, also known as phase invert or polarity invert, involves flipping the electrical polarity of the subwoofer’s input signal. This essentially flips the direction of the subwoofer’s cone movement. In some cases, this can improve bass response by better integrating the subwoofer’s output with the main speakers or the room’s acoustics. However, it’s worth noting that this is not always necessary or beneficial in every setup, as it flips all frequencies 180° in phase. The separate phase adjustment around the crossover frequency will still work!
In summary, while both phase and signal invert adjustments on subwoofers relate to the alignment and integration of the subwoofer with the rest of the audio system, they operate on different levels. Phase adjustment deals with the alignment of sound waves, while signal invert deals with the electrical polarity of the input signal.