Available from an authorized dealer is the Tributaries Series 8 Mk II mono subwoofer cable.

All Series 8 audio cables are meticulously assembled by hand in Orlando, Florida. Series 8 Mark II subwoofer mono cables are optimally designed to work in Low Frequency Effects (LFE) Subwoofer outputs of a pre-amp or receiver. The Series 8 design starts with extremely high grade linear crystal copper (LC-OFC) developed specifically for audio applications.  Tributaries LC-OFC is carefully drawn to produce a low crystal volume per foot resulting in less signal loss and distortion. Conductors consist of multiple solid gauges that are mathematically and tonally chosen to support lower, upper and mid-bass frequency ranges for a dynamic bass sound. Individually insulating each conductor yields zero strand interaction and better sound quality. The precision-twisted Twin-Axial design has dedicated conductors for the positive signal and negative return signal plus a heavy shield that is connected to the source end only. In this design the shield will capture any induced interference sending it to ground at the source end thereby isolating noise away from the input stage of the load. This configuration ensures a clear signal transfer with overall noise rejection. The Mark II cables are silver soldered onto proprietary RCA connectors made with Tellurium (TE) copper contacts increasing conductivity and strength. The end result is a dead-quiet cable that accurately produces a dynamic bass sound.