Can more speakers be added?
Can more speakers be added for use in an additional room?
No. The Sony stereo's speaker connector modules are proprietary, and there are only two of them. You could try cutting off the end connectors and splicing a second set of speakers into them, but this may not work and would probably invalidate your warranty. The sound quality may also suffer. You could also try using the front 3.8mm output jack to connect to a second set of speakers, but this would be a bit unsightly - plus, the sound would shift from rear speaker connector output to front connector output when you insert the 3.8mm jack, defeating the purpose.