M-Audio Studiophile AV 40 Active Studio Monitor Speakers (Pair) (OLD MODEL) 4-inch polypropylene-coated wooferstight, accurate bass 1-inch ferrofluid-cooled silk dome tweetersclear, smooth highs OptImage III tweeter wave guidesprecision imaging for a balanced stereo field 20-watt-per-channel amplifier with Class A/B architectureprofessional design and fidelity Magnetic shieldingreduces interference with other equipment, perfect for multimedia and video work