Rooms have their own "sound" because they impose their own characteristics on audio signals contained within them. It's actually kind of remarkable. Sound such as music coming from headphones will sound the same everywhere. No matter what acoustical environment we are in, the headphones sound the same. That's because the room is not part of that playback signal path. But sound such as music from a loudspeaker will sound different in every acoustical environment. Every room where you set up the loudspeaker will cause the sound you hear to be different ─ sometimes dramatically different; that is because the room is now part of the signal path. Also, in the same room, the loudspeaker will sound different when it is placed in different locations in the room and it will sound different as you move around the room. Similarly, when you are recording a musical instrument, the sound you receive at the microphone will be different in every room and the recorded sound will sound different as the instrument or the microphone is moved.