Archived posting to the Leica Users Group, 2010/06/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Jim, I've hear Levy's recordings and they are great. The main acoustical problem with Kresge Auditorium was the very short reverberation time. Reverberation time is the number of seconds it takes for an impulse sound (i.e. hand clap) to die out. A short reverberation time, say one second or less, is good for speech and solo performances miked close up since echos from the hall don't blur the sound. On the other hand it lends an unwanted sharpness to ensemble music. The sound of the instruments don't blend. A very long reverberation time, say more than three seconds, muddies the sound by adding too much echo. It is like music in a cathedral. Ideally, for ensemble groups you want a reverberation time in the two second range, longer for full orchestras, shorter for quartets. The Kresge auditorium was optimized for lectures. The architects apparently overlooked the fact that the hall would be used for music as well. The problem is similar to that of "sharpening" in digital photos. Too much and the picture appears wirey or grainy, too little and it appears overly soft and fuzzy. Eugene Levy's piano performances were well suited to the characteristics of the hall in the 50s. The fix by BB&N employed reversible panels with sound absorbing material on one side and reflecting material on the other so that the reverberation time could be altered depending on the performance. Not much could be done about the uneven sound dispersal throughout the auditorium except to proved supplementary loudspeakers to reinforce the sound in the blanked out areas. In general, most classical music was composed to be played in halls with wood and masonry construction and elaborate ornamentation that reflected the sound into all nooks and crannies of the auditorium. From an acoustical point of view, the old halls are still the best. It's mostly a question of the mass of the construction materials. Modern materials, steel, glass, and plastic tend to reflect sound too well and must be treated to provide an adequate acoustic ambience. They don't make them like they used to. But I suppose that's more than anyone on the LUG wants to know about architectural acoustics. Larry Z