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What are the pros and cons of the two methods

       Whilst nothing invented by man is perfect, natural microphone techniques have the beauty of simplicity that comes from the cleverest of inventions. Their major advantage is that they closely mimic the way in which we hear. After all, we only have two ears and yet we have no problem hearing music live, even with our eyes closed. Other microphones are not only not needed, they often make the sound worse! This is definitely a case of 'less is more'. We feel that the problems lie more in the restrictions inherent in stereophonic reproduction, where all the sound, direct and reflected comes from in front of the listener, whereas in real life sounds arrive at the listener's ears from all directions. This is a fundamental problem of reproducing sound at home through just two loudspeakers, a limitation partially removed by 5.1 surround sound recordings which can, with a good microphone technique, re-create much more accurately the sense of acoustic space in which the recording was made. The major benefit of naturally made recordings is a sense of solidity, with a perspective of width and depth. Interestingly, the Greek word 'stereo' means 'solid'. The sound is solid because it is sampled in one place, just like human hearing. This means that the reverberation is coherent and consistent. Also, the sound has depth that is almost always lacking in multi microphone recordings. You can hear when an orchestra plays live that the woodwind section is behind the strings and the percussion section is often behind them. You can't hear this on the vast majority of modern recordings, it's as if the engineers think that we're all deaf and need assistance to hear what they obviously think of as 'weaker' instruments. Another problem is the lack of trained and experienced engineers in natural techniques. It takes as many years of experience to know how to use these techniques properly, just as it does to use multi-microphone techniques. The fact that natural techniques are no longer taught makes matters worse.

The use of multiple microphones however, is strewn with problems, some serious. The problem of taking away the balance from the musicians has already been mentioned. This is more serious than it may appear, as musician's balance is a subtle and constantly changing thing, particularly in chamber music where the players have to listen to each other all the time and adjust their own playing accordingly. For an engineering team to even think that they can fake this sort of subtlety is ridiculous. Musicians have been balancing themselves for centuries before the advent of electronic 'assistance'. They do it much better than any engineer.

The use of multiple microphones to cover either groups of instruments or individual instruments is fraught with problems. Firstly, you have the problem of overspill. If you are trying to mike up say the woodwind, you will get overspill from the brass and percussion behind. So if the engineer wants to highlight the woodwind, he will also bring up the brass and percussion to a lesser degree. This may well be musically undesirable. So the engineer has to place the microphones very close to the instruments he wants to control to avoid overspill. This has two problems of its own. Firstly, acoustic musical instruments are not designed to be heard at such a close range. They sound harsh and horrible because at very close range you only hear a segment of the total acoustic radiation of the instrument and that distorts the timbre of that instrument. Secondly, since the sound of the instrument is received at different times at several microphones, microphone signals add at some frequencies and subtract at others: an unpleasant and audible phenomenon known as comb filtering. Thirdly, each microphone will also pick up hall reverberation from a different perspective.

Unlike single point microphone techniques that give real, solid stereo, multiple microphone techniques actually give multi-mono rather than stereo. This is because each microphone has to be placed artificially in the sound stage in the mixer via panpots (which allow the placement of each input to the left, right, center, or anywhere in between on the sound stage) and the resulting sound is a mixture of all the inputs. Some engineers try to get around this problem by using a main stereo pair and then 'spotmiking' everything else. The most common thing is to highlight 'weak' instruments, for example the flute, every time they have a solo. This ignores the fact that any competent composer and conductor would have allowed for this in the orchestration. They will have already thinned out the texture to allow the flute solo to be heard clearly. This basic musical fact seems not to be understood by the majority of producers and engineers. This also results in the flute being acoustically magnified in size as it is zoomed up in the mix. The worst examples can sound as if the instrument is 30 feet long! Another example is that of the misunderstanding of the difference between physical loudness and musical intensity. A note played quietly has less intensity in its sound than a note played loudly. Therefore, there is a difference between a quiet note, artificially boosted in loudness in the mixer to be the same as a loud note and a note played loudly in the first place. This distinction is often lost.

Since the natural ambience of the hall is suppressed when multiple close microphones are used, it has to be 'restored' by artificial means. The way this is most often done is to overlay the acoustic of another venue on top of your own recording, or you can pass your recording through an echo plate. Both obviously conflict with reality, because in live sound, each instrument excites different nodes in the building, depending on its directivity and its position in the building. This is one of the distance cues our brains use to assimilate a perspective. Take it away, and the perspective is lost.