Sonic Electronix offers the Sennheiser HD 700 Over-Ear Headphones for $749.95. Coupon code "HD700_SHH" drops it to $429.95. With free shipping, that's $50 under our mention from last month and the lowest total price we've seen. (It's the best deal today by $87.) These open-back headphones feature angled drivers, a 10Hz to 42kHz frequency response, and detachable cable.