Monoprice offers its Monoprice Premium 5.1-Channel Home Theater Speaker System for $154.99. Coupon code "15MEMORIAL" cuts the price to $131.74. With $38.03 for shipping, that's the lowest price we could find by $59. The four satellite and the center channel speakers each use a 3" mid-range driver and 3/4" dome tweeter. The powered subwoofer features an 8" down-firing speaker and 200-watt amplifier. Deal ends May 29.