M H4n triangulation and it is what gives us the ability to judge distance. The exact same principle applies to our ears. There is another thing we have to add to the equation when recording sound. It’s called phase. You can be in phase (good) or out of phase (not good).
In phase means that the audio waveform of your two stereo tracks goes up and down at the same time. In an out of phase recording the waveforms are offset, so as one goes down the other goes up. This effectively causes the two waveforms to cancel each other out slightly and you end up with a kind of flat, dampening down of the track.
Ok, so you are about to shoot an interview with your stereo recorder in the same position as the camera, the interviewee stands centre frame there for the sound has exactly the same distance to travel to your two microphones. But let’s say that there are other interesting things happening in the shot. For example a man is busking to the left-hand side of the shot. Because of his position the sound wave reaches (on recorder where the microphone placement is side-by-side) the left hand microphone first and then the right hand microphone. This slight delay between the two microphones is called the lag time, and it is because of this that we get out of phase recordings. In the case of the Zoom H4n the microphones are arranged in what is referred to as an XY axes, this means that the two microphones are placed one on top of the other at 90° to each other. Because of this arrangement the sound wave reaches both microphones at the same time. This eradicates the lag time and produces a stereo image that is in phase. The XY axis set up is by no means unique to the H4n. It is a standard practice throughout the recording industry, and is as near to the front pages on how to record sound as correct exposure is to photography. I regard the H4n in the same way as my first SLR, a new and exciting tool in which to learn and progress to a higher standard.
In a time where multimedia is the buzzword, we as independents cannot afford to be ignorant of such basic technologies and practices. It is the understanding and application of these principles that will allow us to shine out in this incredibly competitive industry. Text: Andy Ash
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