It is often an advantage to use a Y-split subwoofer cable (mono to dual-mono), even if the original signal is a mono signal. It is clear that the bass unit itself can be equipped with a double swing coil, or the subwoofer with several units. Most crossovers in subwoofers therefore perform best if both inputs are used. In practice, this usually causes the subwoofer to play a little louder at the same input signal / volume than by simply using one input. Therefore, in order to make optimal use of the subwoofer and the subwoofer has such a stereo input, we always recommend using a subwoofer split cable if no mono or LFE input is specified directly.