General Information
From an old MB Quart brochure (circa late 80s):
The Quart Phone 50
Dynamic, semi-open headphone. Coupling: circumaural. Frequency response: 10 Hz - 22 kHz. Nominal Impedance: 120 ohms (x2). Sound Pressure Level: 96 dB. Rated Power Handling: 0.1 watt. Distortion <0.5%. Weight (without cord): 245 grams.
The Quart Phone 50
Dynamic, semi-open headphone. Coupling: circumaural. Frequency response: 10 Hz - 22 kHz. Nominal Impedance: 120 ohms (x2). Sound Pressure Level: 96 dB. Rated Power Handling: 0.1 watt. Distortion <0.5%. Weight (without cord): 245 grams.
