MartinLogan SW2TD Wireless Transmitter Although correct room placement plays a key role in optimizing subwoofer performance, it can impose the inconvenience of running long lengths of cable through walls, along baseboards or under floors and carpets. The SWT-2 Subwoofer Wireless Transmitter solves the problem and allows you to place your subwoofer in the exact location where it will deliver the best bass. Cable clutter becomes a thing of the past and actual system setup time can be dramatically reduced.