dynaudio M 1.5 System 2-way Passive Near / Midfield Monitor Frequency Response (+/- 3 dB) 34 Hz - 20 kHz Peak SPL 1m, pair (IEC Short Term)> 127 dB peak Peak SPL 2m, 5.1 (IEC Short Term)> 128.5 dB peak Amplifier minimum 70 W (> 100 dB SPL @ 1,5m) Sensitivity (2.83 V / 1m) 88 dB Impedance, Nominal 4 ohm Impedance, HF (200 kHz) 6.2 ohm Resonance Frequency 39 Hz Internal Cabinet Volume 29 liters Bass Principle Bass reflex Crossover Frequencies 2000 Hz Crossover Slope Woofer 18 dB / oct; Tweeter 12 dB / oct Tweeter Esotec 28 mm / 1.1 "soft dome Magnetic fluid, Rear chamber Pure alu wire voice coil, 4 mm die-cast alu front Woofer 175mm / 6.9", One-piece molded polypropylene cone, 75 mm pure alu wire voice coil Weight 17.7 kg / 39 lbs Dimensions (WxHxL) 440 x 300 x 400 mm Dynaudio MCA 650: Dynaudio DCA 650 Pair of stereo power amplifiers. Sold by Dynaudio as a part of an active studio speaker system. The amplifiers are in perfect order. The amps are of High End quality and have almost endless power. MCA650 is 2 x 350W 8 Ohm.