As one of its daily deals, Groupon offers the JBL Duet II Computer Speaker System in Black/Silver, model no. DUET2BLK, for $39 plus $5 for shipping. That's the lowest total price we could find by $11. These speakers feature Phoenix transducers, 20-watt amplifiers, a frequency response of 80Hz to 20kHz, and more. Deal ends July 21 at 1 am ET.