Contents of the lot: A set of American Infinity RS-4001. Comes together with the Service manual and all photos on a CD-Rom. These Infinity speakers have been modified by a professional. With this technical modification the original woofers, as seen on photos 16 and 17, have been replaced by a more powerful set of KEF speakers. The original Infinity woofers had a relatively small magnet and at high volume could not keep up with the two other units. Consequently these speakers sounded somewhat blown under heavy use. The new KEF woofers are equipped with neodymium magnets and bring a balance to the whole set. In addition the now superfluous and sensitive mid-range and tweeter Control Panel has been removed from the signal path. The speakers are pleasant to the ear, not noisy or screeching and now play with full force and flair. If necessary, they can be played at high volume, and are at their best when the input signal is of high quality. It is thus always advisable to use the best quality amplifier possible that can produce sufficient undistorted power. An amplifier that is too weak or is badly adjusted will lose it’s quality output and will distort. This distortion is what, together with the output in DC, destroys more speakers than the use of a too powerful amplifier. Year of production: 1990. Impedance: 4 ohms. Nominal power: 70 watts max. 170 watts. Measures: Height: 57 cm, Depth: 26 cm and Breadth: 29 cm. . Weight: 9 kg / Box. All my audio equipment is professionally checked and tested. At the company in Zuidlaren the equipment always get cleaned and repaired if necessary. The speakers will be sent worldwide in a double box, boxed twice. May also be collected from Haren, near Groningen (NL), of course.