If the instrument is moved to the right side, the sound would first move the diaphragm to the left, producing a negative volage. The stereo effect comes from the fact that the instruments on the right side are on-axis for the right channel microphone and somewhat off-axis (and therefore reduced in level) for the other one.
Microphone Frequency Response: • A microphone ability to hear tones (high and low) across the audible spectrum. When the diaphragm vibrates, it causes other components in the microphone to vibrate. No mic is perfectly linear; the best you can do is find one with distortion that complements the sound you are trying to record. These cheap devices are easy to set up and use. Dynamic mics.
Some microphones have tiny built-in amplifiers which boost the signal to a high mic level or line level. This is known as the "proximity effect", and many singers and radio announcers rely on it to add "chest" to a basically light voice. The condenser microphone employs this principle by having a diaphragm as one of the plates.
On the other hand, a very sensitive mic on vocals might overload the input electronics of the mixer or tape deck, producing distortion. Before it can be used for anything serious the signal needs to be amplified, usually to line level (typically 0.5 -2V). You can then say that instruments on one side of the stage are 180 degrees out of phase with those on the other side, and the closer they are to the center, the weaker the signal produced. The interference that occurs when when an instrument is picked up by two mics that are mixed is a very serious problem. Every engineer has preferences, usually based on mics with which he is familiar. If the instrument is on the left half of the stage, a sound would first move the diaphragm of the bidirectional mic to the right, causing a positive voltage at the output. Close, in this context, is related to the size of the microphone, so the nice large mics with even back and side frequency response exhibit the strongest presence effect. The output is represented by the radius of the curve at the incident angle. Most of us do not have access to lots of professional microphones, but we could probably afford a pair of general purpose cardioids. The distortion characteristics of a mic are determined mostly by the care with which the diaphragm is made and mounted. The reality is different. The cable used must be kept short, less than 10 feet or so, to avoid noise problems. A flat frequency response has been the main goal of microphone companies for the last three or four decades. The Hypercardioid pattern is very popular, as it gives a better overall rejection and flatter frequency response at the cost of a small back pickup lobe. You could hear one cello player and the tympani, but not much else.]. The shotgun is extremely sensitive along the main axis, but posseses pronounced extra lobes which vary drastically with frequency. This is the most significant difference between professional preamplifiers and the type usually found on home tape decks. The microphone noise reduction modul e is a speech noise reduction device designed with a. highly integrated DSP/SOC (on-chip integrated system) speech processor, using speech .
To protect these mics (some of which can actually be damaged by blowing in them) engineers will often mount a nylon screen between the mic and the artist.
To see how these patterns are produced, here's a sidebar on directioal microphones. If the angle is too wide, instruments in the middle of the stage will sound weak, producing a hole in the middle of the image. In a concert recording, where the point is to document reality, and where individual microphones would be awkward at best, it is most common to use two mics, one for each speaker. Otherwise, those instruments closest to the microphones will be too prominent. Microphones work on converting a vibration into an electrical energy. Using dual microphone signal reception, the DSP speech processor can effectively identify dynamic ambient noise through advanced speech-clearing algorithms and filter out … Design of the microphone. As I said, microphone outputs are of necessity very weak signals, generally around -60dBm. This is another part of the microphone mystique. The angle between the microphones is critical, depending on the actual pickup pattern of the microphone.