Control rooms 365 level and with respect to position, because no modes exist to create spectral or spacial variations. Nonetheless, a relatively flat extension of the low fre- quency response into the pressure zone can only be achieved in very damped (absorbent) rooms. For these reasons, no loudspeaker system can be absolutely optimised for low frequency performance without knowledge of the room in which it will be used. Good monitor loudspeakers must perform in real control rooms, and fulfil the job for which they were designed. Good domestic loudspeakers must give pleasing results in less controlled circumstances. There are so many things that a room can do to modify a loudspeaker response that no simple set of idealised test specifications can truly represent a loudspeaker in normal use. 13.6 One system It should by now be clear that the design of the control rooms and their corresponding monitor systems cannot be done in isolation, because the per- formance of either one is dependent upon the performance of the other. This is why many studio designers require some degree of control over the loud- speakers to be used in rooms of their design if they are to put their name to the overall result. Directivity, for example, is a loudspeaker characteristic which may dictate how a particular loudspeaker suits a given control room design. Too wide a directivity pattern in a small control room may induce