Hi. I am not savvy re electronics and need help. I have some old but excellent phase tech PC50/60 speakers that I would like to use in a new surround system with a new av reciever, center speaker and surround speakers. The PC50 woofer is 8 ohms, and the PC60 speakers are 4 ohms. They are configured so R&L leads go first to the passive subwoofer, then to the right and left PC60 speakers. Questions: (1) Can these be used with modern AC receiver that has separate connections for subwoofer? (2) Would I need an additional amp for the subwoofer, such as my old stereo receiver? (3) How would I best hook them up on a modern av receiver? and (4) how much power will I need in the AV receiver? Thank you for any assistance you can offer......