I have several speakers I would like to use with my Sonos system. I am looking into using Sonos Port to connect them, but it seems like the use of Port is limited. There is only one line-in and one line-out. The Sonos FAQs recommend to use a connector for all of the speakers. This means that all of the speakers will have the same reaction to any control - they cannot be individually controlled like the Sonos products. It seems that if I want to be able to control each speaker, I would need to purchase multiple Ports - one for each speaker or set of speakers. Is there a better way to connect a pre-existing system to Sonos?