On the speaker with the amplifier (the right speaker given the label on the back), what are those two circles to the left and right between tweeter and woofer? The one on the left looks like a port, but this seems a bit odd given the big port on the back of that speaker. The other one looks like... a control of some sort?
MonetsChemistLeft circle is for the remote control sensor & also has colored leds that indicate which input has been chosen. The right one is a volume control.