Monoprice offers its Monoprice Premium 5.1-Channel Home Theater Speaker System for $149.99. Apply coupon code "10AMAZON" and checkout with Amazon Pay to drop that to $134.99. With free shipping, that's the lowest in-stock price we could find by $100 and the best price we've seen. 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.