Speakers 4 to 5 of the morning education machine have the best size. The morning education machine needs a lot of pronunciations to interact with children. The size and volume of the sound box is not as big as possible. It needs to be controlled within the range of children's hearing safety. The sound field needs to be balanced, the treble is not harsh, and the bass is not dull. A 4-to 5-inch speaker for an early education machine is very suitable.