122 Recording Studio Design room sound is evenly distributed in frequency and is subservient to the sound of the instrument(s). A parallel exists in the realm of amplifiers. Guitar amplifiers and hi-fi amplifiers are quite distinct devices, and normally cannot be interchanged. Guitar amplifiers have relatively high levels of distortions, but those distortions are chosen to be constructive and enhancing in terms of the sound of electric guitars. However, recorded music played through a guitar amplifier and loudspeaker will sound coloured, and will suffer from a lack of definition. The result will certainly not be hi-fi. Conversely, a guitar played through a hi-fi amplifier and loudspeaker (the neutrality of which are more akin to control room neutrality) will be unlikely to sound full-bodied or powerful. In a similar way it is thus entirely justifiable for a neutral recording room to add to the character of an instrument played within that room, as long as that character enhances and supports the instrument and does not in any way become predominant itself. Therefore, anything in the sound production side of the record/reproduce chain can be considered to be an extension of the instrument, and hence subjective enhancement is usually desirable. Conversely, things in the reproduction or the quality control sides of the chain must be transparently neutral, in order to allow the production to be heard as it is on the recording medium. 5.3 Practical realisation of a neutral room