When listening to music in a room, the sound emitted by the loudspeaker does not only travel directly from the loudspeaker to the listener. It is also distributed uncontrollably in all directions, reflected off the floor, ceiling and walls, arriving at the listener with a time delay and mixing (‘interfering’) with the sound arriving directly. If the level of the reflected sound is higher than that coming directly from the loudspeaker, this is referred to as a diffuse field. In an average living room, this is already the case at a distance of 60 to 80 centimetres from the sound source. This means that, in principle, anyone sitting on the sofa in front of their loudspeakers in an average living room hears music in a diffuse field. This explains why a loudspeaker that is linearly tuned in a free field (i.e. without reflections) usually does not sound completely neutral. In most cases, sound bundling effects of individual drivers in a multi-way system are the reason why the frequency response in the free field differs from that in the diffuse field. If this difference is specifically compensated for using filter technology, the sound transducer, which is correspondingly diffuse field equalised, gains significantly in naturalness and ‘transparency’, especially in very layered and complex musical passages. Music sounds ‘more lively’ and ‘more relaxed’, and the ear also ‘tires’ less quickly during prolonged listening.