The Bose box
is a powered bass module. With the tiny speaker in it, it cannot produce the lowest lows that subs are known for, but it does enhance bass tones. The inputs must be high level speaker outputs from the receiver since the module filters out low frequencies and passes unamplified highs to the little cubes.
The OP probably has to play with Pio speaker settings to enable "large" for L/R so that full range is put out since factory defaults usually presume a sub is used in "5.1" and only output lows to the LFE jack.
btw "subs" that have high level inputs behave similarly.