The original Bink Audio Test warbles to align main speakers to subwoofers by ear when pressed for time or when an analyzer is unavailable are now available for download.
Courtesy of Michael Bink Knowles.
A lot of sound engineers try to align main speakers to subwoofers by using a single sine wave with a frequency equal to the crossover frequency while adjusting knobs, listening for maximum summation or cancellation and then invert the polarity of either main speaker or subwoofer.
The problem with this approach is that you're exposing yourself to only a single frequency whereas in reality a typical 4th order crossover spans about an octave before the speakers are spectrally isolated from each other (10 dB relative level offset).
As long as both speakers are producing the same signal there are an infinite amount of possibilities for being in phase (either with or without polarity inversion) and not on time. Whereas there's only one possible outcome where both speakers are in phase and on time.
On an analyzer (gallery) this will appear as equal matched slopes overlapping each other throughout the crossover range. All other outcomes will have intersecting phase traces but unmatched slopes (tangents) resulting in frequency response ripple throughout the crossover range.
Listening to a single sine wave will not reveal this as is proven time and again by attendants of my seminar because we're not exposed to neighboring frequencies. Should you decide to align by ear then at least use a signal that exposes you to all frequencies of interest like Michael Bink Knowles Audio Test's warbles.
I would like to thank Michael for allowing me to make these files available for download.
Check out the video below for a better understanding.
Headphones are recommended due to low frequency content.