Late design compromises like added seating can ruin a concert hall’s acoustics.

Evidence

The author has spoken to Leo Beranek about Philharmonic Hall, and he is persuasive that changes forced on him toward the end of the project degraded and invalidated his design. Beranek and his colleagues wanted the hall to seat no more than 2400 people, but seating for another 378 people was added at the last minute in the planning process. Nonetheless, specific criticisms having to do with the sidewalk being too far apart to provide early reflections to the center seats, and ceiling clouds being too high and too small to reinforce early reflections, especially of lower frequencies, seemed to be borne out by listening tests. — Eric J. Heller, Why You Hear What You Hear- An…, 2578

Categorization

• DEFINE: Explains ‘early reflections’ — their distance, timing, and frequency coverage determine a hall’s quality.
• SHARE: For someone interested in performance-space design: how added audience capacity and inadequate ceiling clouds broke early reflections.