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2.0 The Subject of Room Acoustics
Acoustics is a complex subject and this text should be treated for what it is, a simple but informative guide. For a deeper understanding, we would recommend seeking out
a range of texts on the subject in conjunction with the purchase and use of basic measurement equipment.
It is important to have a strong appreciation of the huge role played by the room and surroundings on the overall sound of the audio system. The air contained within
the room is the link between the output of the loudspeaker and your ear. How this air behaves is dependent upon the attributes or characteristics of the room. It follows
that a better understanding of basic acoustics will assist in making decisions about the way in which the room and subsequently the system can be initially installed and
ultimately improved.
Room types fall between two extremes. A room can be 'dead' on the one hand - being full of highly acoustic energy absorbent materials - or very 'lively' on the other hand
with a high proportion of non-absorbent, hard, reflective surfaces. A combination of materials with different characteristics to achieve a balance between these extremes is,
of course, preferable to either extreme where performance and accuracy will suffer.
The contents of a room will impact on its overall acoustic character. As you would expect harder surfaces like glass and concrete tend to reflect and/or diffuse a broad
bandwidth of acoustic energy. Complimentary materials that are soft and thick in section such as heavy natural fibre curtains will tend to absorb a broad band of
frequencies.
2.1 Standing waves
When sound waves reflect between two parallel surfaces, the distance apart being equal to half the wavelength or less, dependent upon wave size, resonance modes
referred to as 'standing waves' are created. The standing waves in your room will distort the frequency response of your system sympathetically boosting or cancelling
certain frequencies. If a certain standing wave frequency is acoustically isolated from its modal neighbours its effect is more likely to be audible and problematic. This can
compromise the accuracy of any loudspeaker.
PRECISION SERIES MANUAL
REV 1.3
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