The Heco Superior 640 is a compact, 3-way closed speaker manufactured by Heco GmbH from 1989 to around 1990 in Germany. It is available in various attractive finishes including walnut veneer, oak veneer, mahogany veneer, ash black, and ash white, with special versions in sanding varnish colors upon request. The dimensions of the speaker are 490 mm in height, 260 mm in width, and 315 mm in depth, with a weight of approximately 12 kg. The original price was around 1600 DM per pair. The speaker is equipped with a single 220 mm woofer, a 120 mm midrange driver, and a 19 mm dome tweeter, providing a frequency response from 30 Hz to 35 kHz. The efficient design has a power handling capacity of 110 watts nominal and 140 watts music, with an 88 dB sensitivity rating at 1W/1m and an impedance of 4 Ohm. Crossover frequencies are set at 250 Hz and 2,500 Hz, enhancing its capability to deliver balanced audio across various frequency ranges.
