In the bass region, the in-room frequency response is by far what matters the most to the ears.
You see, the ear’s time-domain resolution is very poor at long wavelengths: We cannot even detect the PRESENCE of bass energy from less than one wavelength, must hear multiple cycles to begin to detect pitch. So by the time we BEGIN to hear the bass, the room’s effects are all over it (think of how long the bass wavelengths are in relation to the in-room reflection path lengths), thereby swamping any initial phase coherence or lack thereof. The transients and overtones which give us the timing information of bass instruments are much further up the spectrum.
On the other hand, the ear is very good at hearing changes in sound pressure level at low frequencies. This is predicted by the way equal-loudness curves bunch up south of 100 Hz: A 3 dB change at 40 Hz can be perceptually comparable to a 6 dB change at 1 kHz.
To the extent that the phase of the subwoofer(s) affects the in-room frequency response, it matters. For those who have a phase control on their subwoofer’s amplifier, it is a useful tool for getting a good blend between mains and sub(s). It is not as powerful as the some of the other controls (such as gain and crossover frequency), but it is still useful. Adjust the phase control for smoothest frequency response (after adjusting the gain and frequency controls) and you will have made the biggest improvement it has to offer in the area that matters the most.
Duke
subwoofer manufacturer
You see, the ear’s time-domain resolution is very poor at long wavelengths: We cannot even detect the PRESENCE of bass energy from less than one wavelength, must hear multiple cycles to begin to detect pitch. So by the time we BEGIN to hear the bass, the room’s effects are all over it (think of how long the bass wavelengths are in relation to the in-room reflection path lengths), thereby swamping any initial phase coherence or lack thereof. The transients and overtones which give us the timing information of bass instruments are much further up the spectrum.
On the other hand, the ear is very good at hearing changes in sound pressure level at low frequencies. This is predicted by the way equal-loudness curves bunch up south of 100 Hz: A 3 dB change at 40 Hz can be perceptually comparable to a 6 dB change at 1 kHz.
To the extent that the phase of the subwoofer(s) affects the in-room frequency response, it matters. For those who have a phase control on their subwoofer’s amplifier, it is a useful tool for getting a good blend between mains and sub(s). It is not as powerful as the some of the other controls (such as gain and crossover frequency), but it is still useful. Adjust the phase control for smoothest frequency response (after adjusting the gain and frequency controls) and you will have made the biggest improvement it has to offer in the area that matters the most.
Duke
subwoofer manufacturer