This new loudspeaker module fits everywhere where previously 20mm x 40mm rectangular speakers were installed. With the help of the built-in passive radiator in conjunction with two rectangular speakers, the module achieves a significantly improved bass response and achieves a remarkable sound pressure even at high and mid-range. The module is particularly suitable for diesel or steam locomotives, where emphasis is placed on contemporary bass reproduction. The speaker fits perfectly with our LokSound 5 micro, LokSound 5 or LokSound 5 L decoders.