Sony STR-DA3300ES Operating Instructions Manual page 47

Tip
The size of a speaker (LARGE/SMALL) is
determined by the low characteristics. The
measurement results may vary, depending on the
position of the optimizer microphone and speakers,
and the shape of the room. It is recommended that
you follow the measurement results. However, you
can change those settings in the Speaker settings
menu. Save the measurement results first, then try to
change the settings if you want.
47 GB