I set the phase by ear. My subs only have the option of 0 or 180. The option to set phase is only to eliminate the situation where the bass wave from the sub and the bass wave from the mains are cancelling each other out( peaks vs. valleys ). You ideally want both to be in sync.
How do you use subwoofer phase control ?
Recently obtained 1986 era Duntech Thor powered large bench-sized subwoofers with outboard crossover box. No instructions about dialing in the phase somewhere between 0 to 180 degrees. What does one do to choose an optimum setting? Is one sub adjusted separately, and then later the second if allocating one sub per channel? May simply be using one of the subs equidistant between stereo Duntech wall mounted speakers as room size dictates due to massive "coffin" appearance of each sub. These subs specifically designed to complement these wall mounted speakers. Quite a contrast from the modern micro-sized subwoofers such as a Carver.