The speakers are each connected to a power outlet. On the back you have a choice between TRS (quarter inch plugs), RCA, or XLR. These are studio monitors so they aren't cheap. Each speaker retails around $200. You can go down to the Rokit 5 but after you hear the 6 or 8 you may not want them.
found some m audio bx5 d2's same price as one of those. but same kind of set up. could a y cable be used? 1/8" to dual 1/4"? or 3.5mm to dual xlr... same thing