From Greg on another forum...

The AS-Si-DB-Y cable is just that: a cable. There is no switching from one transducer to another either within the cable or the unit.

When you use the AS-Si-DB-Y cable you are disconnecting the 2D portion of the Side Imaging transducer and connecting up the DualBeam transducer in its place. To the unit it all looks like one transducer. The 2D portion of the Side Imaging transducer no longer has an electrical connection to it and so does not operate.

img]http://forums.sideimagingsoft.com/index.php?action=dlattach;topic=4469.0;attach=7018[/img]