The older Logitech Z-640s are in use here. The X-530s are seen OEM for %4.99 at
http://www.newegg.com/Product/Produc...82E16836121126
You'll want the 70w RMS over the lower powered junkers seen for less at
http://www.newegg.com/Product/Produc...=%2425+-+%2450