Hifonics Titan Series TXi 1700 Owner's Manual page 18

Phaseshift
Phase Shift Settings
In the most cases the built-in position of the Subwoofer is not optimally to the position where the listener takes place. You have to
imagine that the Signal of the Subwoofer is a sinus curve. That means at the upper and lower excursion of the sinus curve the
subwoofer reaches its maximum level. But the problem is that the driver do not often sit at the position where the sinus curve has
its maximum excursion. When you move your head the amount of bass is changing in some cars. This is a sign for a wrong built-in
position of the subwoofer.
without PhaseShift
Subwoofer
Sinuscurve
Figure 1: Subwoofer-system without PhaseShift. The Bass is not good and have no pressure.
Figure 2: With changing the Phase you can virtuelly move your subwoofer, so the listner sits in the maximum level of the sinus curve.
So the subwoofer is more pressureful.
18
Special Features
TXi 1700
Figure 1
with PhaseShift
Subwoofer
Sinuscurve with PhaseShift
Figure 2