Poorly coupled added volume produces a double-slope reverberation fault.

Evidence

The advantage of this type of approach is that, theoretically, it can uniformly cover the whole frequency range with its modification of T60. However, there are disadvantages. First, the expense is high, as a significant amount of extra volume has to be applied. Second, properly coupling the extra volume into the space is difficult to achieve. If it is done wrongly, one can have a double slope reverberation fault, as discussed in Section 6.1.15. Or the extra space can have little measurable effect if not coupled strongly enough. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1920

Categorization

• DEFINE: Defines the ‘double slope reverberation’ fault the chapter references earlier; coupling strength determines whether a coupled volume even registers.