The Technics SB-HD501 is a compact set of 2-way bass reflex bookshelf speakers, originally released in 1999 as part of the popular high-end SC-HD501 micro-Hi-Fi system. Characteristic of these speakers is that they are designed for Bi-Amping / Bi-Wiring. This means that the highs (tweeter) and the lows (woofer) are controlled separately from each other via four speaker connections on the back. Main Specifications System: 2-way bass reflex (2 speakers per cabinet) Load capacity (Input Power): Low tones (Woofer): 60W (Music) / 30W (DIN) Highs (Tweeter): 30W (Music) / 15W (DIN) Impedance: 6 Ohm Drivers: 120mm cone woofer 25mm semi-dome tweeter Frequency range: 50 Hz to 46 kHz (-16 dB) Sound pressure level (Sensitity): 86 dB Dimensions: 175 x 287 x 225 mm (Width x Height x Depth) Pictures are all original of this lot and part of description!