Several have already mentioned Natural Sounds in Framingham; +1 to them.
I was in town to visit family and had some time to kill. So I walked into the store and told them: I was from out of town and thus, it was highly unlikely that I would buy anything from them so I didn't want to waste their time. But if they didn't mind I'd walk around and see what they had on display.
They were super nice: said there were no customers in store so there was no problem if I even listened to a system. They took me to a room (Ayre amplification; don't remember speakers) and played for me and also chatted for a while. Super nice people, nice equipment, and great attitude. If I was living in that area, I'd definitely buy from them.