A:AnswerIt can only be paired with another xb-10. If you want more than 2 speakers you can upgrade to a xb-21 or 25 not sure about the number but these speakers can be party linked up to 100 speakers. The xb-21 or 25 is about $25 more than a xb-10.
A:AnswerI'm a musician and I'm making an educated guess... (I don't own an SPL meter.) I would estimate the top end output is going to be around 80-85 db. Some mild distorting occurs when you push it that high. 70 db is easily accessible without distortion.