dave570, the Røde NT 4 is a stereo microphone based on a pair of coincident cardioid capsules set so that each one points 45 degrees away from the intended "center line" of the recording.
Røde microphones in general are nothing to be ashamed of, but that configuration just doesn't make sense for the kind of music recording that people here mostly do. There are close-miking applications for this type of microphone; stereo microphones are more of a Good Thing in studios than many people seem to realize until they try one. But as the main overall pair for concert recording, I would never use coincident cardioids with only a 90-degree angle between them--not even with microphones of much higher quality.
A cardioid pattern isn't at all "sharp." It's really just an omni with slightly reduced sensitivity at the sides and distinctly lower sensitivity behind it (though this directional pattern often varies significantly in different frequency ranges; most switchable-pattern microphones have a "cardioid" setting in which the low frequency pickup pattern is much wider than the pickup pattern in the midrange. Many manufacturers show their microphones' patterns only at 1 kHz and not also, say, at 50 to 100 Hz. But I digress).
The main thing is, in most normal concert recording situations the microphones aren't close to any particular sound source, so a ±45-degree angle between two cardioid capsules doesn't give enough differentiation between the left and right microphone signals to distribute the apparent sound sources across the width of the stereophonic "sound stage." The two capsules end up picking up largely the same information as each other, since their patterns overlap so much. The result is a recording that is largely monophonic--during playback over loudspeakers, all the apparent sound sources tend to crowd in together at the center of the stereo image. Good stereo imaging requires a greater difference between left and right signals than coincident cardioids at so narrow an angle can produce in a non-close-miking situation.
If on the other hand your miking was quite close-in, the balance would then be weighted heavily toward whatever sound source the mikes were closest to. For most concert recording that's not any good, either--though as I said, studio engineers (or even live sound engineers with stereo P.A. systems) can use this effect to advantage, and the NT 4 has gotten some good reviews from studio magazines.
It's much more difficult to manufacture good-sounding capsules with greater directivity than cardioid, but in an X/Y stereo microphone that's doomed to have a fixed angle between its capsules, no switchable patterns and no M/S capability, supercardioid capsules would give a better stereo image. Alternatively, a good pair of small axial cardioids in an "ORTF" arrangement can be a very useful thing. I used to have a microphone like that (a Schoeps MSTC) and it proved to be quite a workhorse.
--best regards
Topic: Rode NT4? (Read 13456 times)