This new loudspeaker module fits everywhere where 20mm x 40mm rectangular loudspeakers were previously installed. With the help of the built-in passive radiator in connection with two rectangular loudspeakers, the module achieves a significantly improved bass reproduction and also achieves a considerable sound pressure level in the highs and mids. The module is particularly suitable for diesel or steam locomotives where modern bass reproduction is important. The speaker fits perfectly with our LokSound 5 micro, LokSound 5 or LokSound 5 L decoders.