Fun Stuff > BAND

Let's talk choral music.

<< < (11/17) > >>

pwhodges:
Here's another concert:

German Romantic Church Music

Program:

Brahms - Geistliches Lied
Mendelssohn - Veni Domine
Mendelssohn - Verleih uns Frieden
Mendelssohn - Hear my Prayer
Reger - Toccata and Fugue in D minor
Rheinberger - Abendlied
Bruckner - Te Deum

Keble Chapel, Oxford, is remarkable building, and accordingly is Grade 1 listed.  The interior is tiled throughout in glazed tiles, so the acoustic is rather literally bathroom-like!  This makes it hard to record in, especially when the choir positions itself for the concert several feet further back than it was in the rehearsal...  Actually, if you accept the aim of recording the true sound of a cavernous acoustic, it's worked rather well, I think.

This is the chapel, with the organ very high up to one side:



Here is my microphone (it's a small surround mic), with tile mosaics behind:



And here's the recorder sitting at the foot of the stand:

Barmymoo:
That chapel is gorgeous (I'd be loyal and say that my chapel is nicer, but it just isn't true)! How audible is the recording? We're recording in Ely Cathedral's Lady Chapel later in the summer, and we were singing there a couple of weeks ago. It is possible to sing an entire chord by yourself due to the ludicrous fifteen-second acoustic so I'm intrigued to see how that will work out.

pwhodges:
The recording is better than I expected (I could do a bit better if I was able to arrange the choir for recording rather than a concert, but it's fine).  The reverberation time is only about 6 seconds, but the critical distance (aka reverberation radius) is very short - barely 10 feet, I say, though I haven't measured it (that's the distance at which the reverberation is as loud as the direct source from the source).  That's the aspect that makes recording harder.

Anyway - it's linked there for you to listen to; the Brahms and Rheinberger are especially recommended.

Redball:
I've downloaded, but haven't had the opportunity to listen yet. As I said a few weeks ago, a friend here in AZ gave me a theater-in-a-box setup. I listened to your trio demo, but had a hard time picking out the location of each voice. It may be my placement.

I get the operation of a binaural mic, I suppose, with the mics aimed away from a center. But a surround sound mic? Is that set up for right and left of the choir and right and left of the reverb?

pwhodges:
I'll be putting the surround files of this concert somewhere in due course, but not straight away.


--- Quote from: Redball on 25 Mar 2013, 15:46 ---I get the operation of a binaural mic, I suppose, with the mics aimed away from a center. But a surround sound mic? Is that set up for right and left of the choir and right and left of the reverb?

--- End quote ---

The usual way of recording surround is somewhat as you outlined - and is no more defined than what you wrote. 

What I do (ambisonics) is different.  An idealised description (the theory of why this is insufficient as it stands is beyond the scope of this margin) is that the microphone is measuring the pressure changes at at point (that's the same as an omnidirectional mic recording a mono signal) and also the movement of the air as three orthogonal velocity vectors (equivalent to the output of three figure-of-eight microphones).  The decoding into loudspeaker signals attempts to drive them so that the original pressure changes and movement are recreated at the centre of the loudspeaker array. You can easily object that (1) the head is larger than a point, and (2) a point is in any case an impractical area of reproduction for multiple listeners - however, in practice, the simple theory outlined above is not all there is, and it actually works out pretty well.

Some of my older recordings were made with a microphone assembled from an omni and figure-of-eight capsules; but they can't be made coincident, which the theory requires, and so better results are got by using four cardioid or sub-cardioid capsules placed close together on the faces of a tetrahedron and matrixing them to generate the required signals.  In fact, the patterns of the derived mics are typically better than can be obtained from physical capsules which claim to have those patterns!

Since many people (including recording engineers) don't get the idea of coincident mics for stereo, they are even less likely to get it for surround!  However, there is solid theory to justify the methods I use in preference to any alternatives; and one of my aims is to generate plenty of examples of practice to go along with it - which is why some of my recordings have been used in talks and demos at AES conferences and the like.

Note that what I have described is truly three-dimensional - the practical case of surround in a plane is already a compromise compared with the whole deal.  Oh, and this theoretical framework, and the microphone with which to record it has been available since a couple of years before 1980.

Navigation

[0] Message Index

[#] Next page

[*] Previous page