Main Specifications. Product Description AKG K 501 - headphones Product Type Headphones. Localisation English. Recommended Use Home audio system. Connectivity Technology Wired. Sound Output Mode Stereo. Response Bandwidth 16 - 30000 Hz. Headphones Type Headphones - binaural. Headphones Form Factor Semi-open. Headphones Connectivity Technology Wired. Sound Output Mode Stereo. Response Bandwidth 16 - 30000 Hz. Sensitivity 94 dB/mW. Impedance 120 Ohm. Headphones Type Headphones - binaural. Headphones Technology Dynamic Headphones Form Factor Semi-open Total Harmonic Distortion (THD) 1.0%. Magnet Material Neodymium.