sábado, 5 de septiembre de 2015

Concert hall originally designed for acoustic performances vs. an amplified one

If an architect is doing an acoustically sensitive job then they will hire an acoustic consultant along with a theater consultant in order to help with the elements of the room design that require such a specialty.

I forgot to add that most architects and consultants look at acoustics as a sort of magic/spiritual field since it's really basically an unknown quantity when it gets to a certain level. They know some things that work, but once it gets super refined what makes a good room and what makes a bad room is really about incantations and other witchery.

Architect here, entry level designer. We take acoustics very seriously when designing a building that is intended for musical displays. Usually larger firms have actual departments for sound design, not just for theaters but ALL office buildings use this now. Even places you work use acoustics. LEED design requires all buildings to have a certain acoustic level. Smaller firms usually don't do project that require such design, or sometimes send it to a third party.

Boy though, they don't always get it right. I know of a LEED building that includes a performance space/stage that is simply unusable. It was designed with the intention of using it for high school band/orchestra performances, and it was only used for such for a single performance season during the building's first semester of operation. The sound was so bad they simply decided to play concerts in the gym from then on-- and we all know how bad a large, hard-sided box with all solid surfaces will sound. The acoutstically crappy stage space ended up being used as a rehersal site only (and for storage).  

"Here's a counterpoint to that, though. Most rental use of live performance venues these days are designed to be amplified. Music performances of all kinds, theatrical performances, dance performances - all usually include sound design or playback that necessitates the use of a good PA system. Would they still if everywhere they went had good natural acoustics? I think so. It a) allows you to do things you couldn't otherwise do and b) if done right, can sound more present/closer to the audience than even the very best acoustic concert halls in the world.
I work as the head of sound at a prestigious concert hall originally designed for acoustic performances. It has "wonderful" acoustics, but on 90% of the actual rentals that keep us afloat, we fight a losing battle against the acoustics: what helps an acoustic performance, acoustically, only hurts an amplified one. Sound because mushy and reverberant, percussive low sounds like a kick drum coming out of a PA system seem to last forever and are entirely indistinct on each hit. Even speech is hard to understand. On many events I find myself wishing for a theatre that "eats sound," as you say, because then I could actually have some control of what the audience hears out of the PA. And it would be much clearer.
We have a million-dollar PA system, with very tightly-controlled coverage that doesn't hit any walls where the audience isn't sitting, so we get by, but even so, the system is fighting the very concept of the space the whole way, and sound simply bounces everywhere.
Of course, nothing beats this space for a solo amplified cello and piano onstage. But such performances do not keep a venue afloat, these days.
And I find this to be a very common problem across so-called "multi-use venues" these days, which have some reflective acoustic surfaces coupled with a modern PA system. Which do you really want? 99% for the time such spaces never once actually see a fully-acoustic performance. The acoustic features of the space only serve to fight against every single actual performance in it."
I see what you're saying, but there's something powerful about an unamplified performance that you're not going to get from an amplified performance. When an extremely talented soprano like Sondra Radvanovsky hits a high note that blows your ears off in the cheap seats without the aid of a mic, it's visceral and exciting, and that effect can't be recreated with amplification. A truly pianissimo pianissimo makes an unamplified fortissimo even better.

I once visited the Colon theatre in buenos aires (i live in buenos aires) and the room was empty, two guys talking on the stage, I guess they were planning some upcoming thing. Anyway, we were stating very far away, right after entering the auditorium. Now these two guys were almost whispering. I could hear everything they said o.O 

The total sound pressure field from multiple sources is simply the sum of the sound pressure fields from the individual sources. Sadly, I'm not awesome enough to explain why this is true without maths though (essentially, it directly results from the wave equation being a linear PDE). However, supposing we had 2 Cellos playing at the same loudness, we wouldn't get twice the volume. There are two reasons for this. Firstly, doubling the sound pressure doesn't double the apparent loudness (hence why the decibel scale is often used). Secondly, 2 Cellos are rarely vibrating totally in sync, i.e. there'll be a phase difference (so there'll be some interference), and this phase difference is random. So while 2 Cellos are louder than 1, they are not twice as loud.
Source - an acoustics module I did as an undergrad Engineer. These notes are pretty good for the mathematically inclined though


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