How are you guys setting your subwoofers up to work with your headphones? I can't seem to figure out how to run my sub without my speakers being on.
We would need to know your configuration of gear (along with what types of inputs and outputs are supported on the gear) to answer your question. The answer may also vary depending on the brand or model sub.
Share you config and I'll take a shot at it if I can. Your other option is to ask a vendor like ACI, which have a "circle" set up on Audiocircle.com. Post questions there and they will be answered by ACI owners and Mike from ACI (Mike has been very responsive to my questions).
For the K1000 specific questions, again feel free to ask here.