I have a new Sony soundbar which I want to connect my outside speakers to / via the subwoofer. The outside speakers have 4 or 8 ohm options - can I use these speakers with my 2.5 ohm subwoofer - should I use 4 or 8 ohm? Can I connect both outside speakers to one port on my subwoofer? My plan is just to disconnect one of the surround sound speakers when I want to use my outside ones