Powered Speaker Cables

What are they ?

Sounds like one may risk getting electrocuted by these things.

Do you mean the Audioquest DBS system? This is available on a whole range of cable types. Do you mean the cables for the sort of speaker used in Public address systems? There are powered (active) HDMI cables which boost the signal for very long cable runs. 

I use the Gold Series power cables from Cullen Cable for my two powered subwoofers. They are very reasonably priced and beautifully handmade.   The power flow goes from the wall socket to a Shunyata Hydra-2 power conditioner via a Shunyata Venom 14 HC power cable and then from the Hydra-2 to the subwoofers via the two Cullen Gold Series power cables.  With this sort of complex power delivery, it is hard to identify the respective contribution of each component.  However, the Cullen products certainly seem to carry their own weight.  Overall, the sound from 80 Hz down in my system is amazing == clear, powerful, and easily delineated among tones, even at 28 Hz and lower.  They are well worth considering; the site is www.cullencable.com.