Last night I went to a concert at University of Colorado's Grusin hall, which is named after Dave Grusin, the jazz musician. It's a sonic wonder, but not in a good way. Imagine the largest Live-end dead-end room you ever saw, fill it with seats, and put the stage on the live end and you've got Grusin. I hadn't attended a concert at Grusin in at least nine years. I remembered that it was a dreadfully dead-sounding hall, but knowing and experiencing are two different things. Because I love my niece Chelsea, who was a member of the chorus, I was determined to stay for the entire concert.
During the concert, which was primarily a 30-voice chorus with minimal piano accompaniment, I could hear each voice clearly, especially during solos, yet the ensemble sound had a hooded, almost muffled character, as if someone had used an equalizer to cut off the high frequencies.
Out of curiosity I took out my iPod and opened AudioTools and measured the dB levels. When the room was quiet the meter read 55dB A-weighted. When the entire chorus was swinging full-bore the loudest dynamic peak was 103dB. Although 103 dB was loud enough to make my wife cover her ears, 103 dB is not uber-loud. The reason it seemed so loud to her was that most of the sound was made up of frequencies between 100 and 1000 Hz. This is the most sensitive part of the entire human hearing range because it happens to be the frequency spectrum of the human voice. According to one chart I found, the lowest frequency for a bass is 80 Hz and the highest for a soprano is 900 Hz.
By the second half of the concert I got sufficiently accustomed to the hall sound that I could listen through it to enjoy the music. But I started thinking, "What if this were the best-sounding concert hall within an hour drive?" Then I gave a deep thanks that the University of Colorado also has another concert hall, Macky Auditorium, where I've been making live concert recordings since 1994.
While Macky ain't exactly Carnegie Hall, it's still decent, with some degree of reflectance and hall sound. After the first year that J. Gordon Holt and I recorded there he devised an EQ curve to add back in some of the bass frequencies that are lost because of Macky's latticework proscenium shell, which does little to reinforce frequencies below 50 Hz. Macky was originally built to house a big pipe organ, which currently needs about $100,000 worth of repair to be fully operable. So instead of a solid roof over the stage there's a lattice so the organ pipes behind and above the stage can be heard. The organ's dead but the holes remain.
Back to Grusin. As I left the concert I thanked my lucky stars that we have multiple venues in the Denver/Boulder area to hear live acoustic music. I also put a big yellow sticky note inside my brain so the next time I have to attend a concert at Grusin I'll be ready for a night of straining to hear the music, even at 103 dB.