Choir/orchestra recording - opinions?

Posted: Sun Jun 15, 2008 8:18 am

I am not sure about the Doppler effect and recording

Here is some info on the Doppler effect http://en.wikipedia.org/wiki/Doppler_effect

I can see standing waves or reflections off near by physical features but since neither the soloist or the microphone are moving I am not sure about how the Doppler effect is involved but would be interested in hearing Cucco's explanation.

I know that a lot of problems exist that are caused by phase problems and that many times what we think is something else is actually a phase problem rearing its ugly head.

I go so far as to carry an oscilloscope to some recording sessions just so I can look at the overall phase and it has saved my butt more than once.

Cucco, I would be very interested in your Doppler explanation.

Posted: Sun Jun 15, 2008 8:41 am

Okay...I knew I'd open a can of worms on that one... Wink

I was really throwing that in as a consideration only, but there has been quite a bit of research done on this in one of the programs that I've been supporting for the Army. On one of our platforms, we've been developing a system (the Boomerang) which will detect the sound of sniper fire and determine its origin. This system uses an array of sensitive microphones and the varying intensities and pitches can tell you from which direction, the approximate distance and the likely type of weapon being fired. There was one problem that they kept encountering and that was that mics facing away from the sound source (analogous to the rear facing portion of the ribbon) were receiving slightly different information than the front facing mics. This was creating anomolies. It was determined that sound moving away from the mic capsule had a different profile than sound moving towards it - particularly at very high frequencies. This is due to the movement of the air molecules themselves, not the source or the mics. At extremely high frequencies, it could even be caused by the movement of the diaphragm as well, but these were quite higher than the equipment needs to operate correctly.

Again - I was really just throwing that in there to see who was paying attention. Doppler can cause anomolies, but the likelihood of the intensity being high enough to be a problem in *our* field is quite unlikely.

Posted: Sun Jun 15, 2008 8:45 am

Just one interesting addition Tom -

The wiki article was pretty good, but notice one of the items which can cause the effect is not just the movement of the source or the observer but the medium (the air molecules) as well.

Posted: Sun Jun 15, 2008 11:36 am

"There was one problem that they kept encountering and that was that mics facing away from the sound source (analogous to the rear facing portion of the ribbon) were receiving slightly different information than the front facing mics."

Can you draw a picture without getting in trouble.

I'm thinking wave interference causing Doppler shift.
My heads hurting.

Posted: Sun Jun 15, 2008 11:57 am

Hey, you can also do what one of my former bosses did for the Baltimore Symphony. He used to put up approximately 8 microphones hung over the orchestra. He would only use three. The others were there just to look good and look the part. And now since we have convenient portable multi-track recorders, you can record all of those and mix after-the-fact. Then you can do that through speakers and not headphones. It ain't 1980 anymore. So life is a lot more convenient.

Yeah, the national Cathedral. The world's greatest reverb chamber. You can't understand what people are saying 10 feet away from you. You have to highlight Mike everything! Otherwise it's just a pool of reverb. So, yeah, I'll put out extra microphones at overly reverberant venues. I may be a minimalist when it comes to recording but not when it comes to brains. I don't believe in technical perfection. Just good sound.

Perfectly imperfect
Ms. Remy Ann David

Posted: Sun Jun 15, 2008 2:52 pm

Most of the groups we work for don't really want to pay for the recording let alone post production things like mixing down.

It may give audio engineers a lot more flexibility to do classical in multi track but the people who are paying the bills don't want or need the flexibility and want the recordings done as simply as possible with as little costs as they can get away with.

Posted: Tue Jul 01, 2008 3:27 pm

Dear fellows

Can anyone advise me on resources about classical music recording (chamber, orchestras, choirs)?
I've been trying to gain as much experience as I can just by "doing it", but I'd like to hear what many others have to say

Thank yoi all

Miguel Almeida
Lisbon, Portugal

This topic sponsored by: