Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Annoying hum

Looked good, sounded good. Then I noticed the low-volume hum (60 Hz?) coming from the bass ports on the back. The lower you turn the volume, the louder the hum, though it was always very subtle. The more I tried to ignore it, the more annoying it became.Repositioning the unit had no effect, nor did moving the cord or antenna or trying different modes (CD, radio, aux). The power cord has a two-pronged plug, and there was no way to ground the unit to see if that would solve the problem.Since this was to be used right next to the bed and normally played at low volume, the hum was unacceptable, particularly at the price of this radio. Paying shipping to return the radio has also left a bad taste in my mouth.Very disappointing.