Beovox MS 150

11th February 2009

The very distorted sound that these loudspeakers produced gave the impression that the mid bass drivers were defective. Moving the cones carefully by hand did not reveal any rubbing or loose parts so the crossover circuit was investigated. It was found that the contact resistance of the protection relays was quite high (a couple of ohms) and varying. It would of course be possible to short out the relay contacts but as the tweeter and midrange units are both delicate and no longer obtainable this is not a good idea. The relays are also of an unusual type but they can be dismantled and the contacts cleaned. In the case of these particular loudspeakers this provided a complete cure. [Beovox MS 150]