An RP visitor asks how he would record a symphony orchestra. Does it need sixty microphones? Or could you do it with two?
I want you to give me an advise, about how to record a Symphony Band, and where to set my mics to capture a good ambience from the instruments... How many mics do you suggest me, and where to position them to receive the liveness of the Symphony Band.
I will appreciate your help...
Tony Barragán From Tampico Mexico
Recording a symphony orchestra of sixty or more players for the first time would be a daunting prospect for any engineer, so how exactly do you go about giving it your 'best shot'?
The first thing to remember is that in popular music, we usually don't care about what the instrument actually sounds like, the priority is to get a good sound in the context of the recording. So we close mic each individual instrument because that is what gives us the sound we need.
Not so with an orchestra though. The priority with an orchestra is to get a recording that sounds like an orchestra, with no 'improvements'. And the best way to achieve this is to start by thinking about how people ideally listen to an orchestra, from a high-price ticket in the front few rows of a concert hall with excellent acoustics.
You could put a pair of microphones in this position and record the orchestra as though the mics were an audience member's ears.
Unfortunately this doesn't work. The human brain has the ability to process the information supplied by the ears and focus on the sounds it wants to hear, and to ignore other sound that it doesn't.
In this case, the reflections from the walls of the auditorium are too loud. The brain doesn't mind, but microphones do - they pick up everything within their coverage angle and the recording would be hopelessly reverberant.
So you have to move the mics closer. The problem now is that the mics are much closer to the front rows of instruments than the rear rows. This is exaggerated when you move in closer.
The answer to this is to raise the microphones. I have often been heard to say that, "You can't get too high". Well I suppose you can, but heights up to four meters are certainly useful. This gives an overview of the orchestra that will pick up every instrument clearly.
Some people find this difficult to believe, but you can indeed record an orchestra very successfully with just two microphones, provided you experiment extensively with microphone positioning.
The only problem left is that most classical music CDs are not recorded like this, but with additional mics, and to a certain extent it is necessary to make a recording that sounds the way people expect.
The drawback to the two mic technique is that the orchestra does not have the upfront, exciting sound that most listeners prefer.
The solution is to set up additional mics, one or two per section of instruments. You could quite easily provide enough coverage with a dozen mics.
The purpose of these mics is to add a little 'presence' to the instruments. The way to set the levels is to listen to the output of the main pair of microphones. Then bring up each sectional mic to the level where it just makes a difference, but a difference that is hardly audible. That is usually enough.
And you know...? It isn't rocket science. In an auditorium with good acoustics it is surprisingly easy to get a good recording of a symphony orchestra. In a school hall it might be another question... for another day.