In music, an ensemble consisting of four musicians or singers is called a quartet. The most widespread among them was the string quartet, consisting of two violins, viola and cello.
It appeared back in the 18th century, when amateur musicians, gathering in the evenings, spent their leisure time playing the stringed instruments. Over time, prominent musicians began to unite in quartets. Such ensembles performed at the courts of princes, in the noble rooms, and since the 19th century. – in concert philharmonic halls. Now the string quartet is one of the most common types of chamber ensemble.
However, there are still a number of varieties of quartets. By the composition of the instruments, quartets Continue reading
To describe sound fields in acoustics, the sound pressure p, measured in Pascals (Pa), is widely used. As with electrical quantities in sound engineering, it is usually more convenient to use a logarithmic scale here. At the same time, the concept of sound pressure level (SPL) is introduced L = 20 log (p / p0), where p0 = 2 x 10-5 Pa is the sound pressure at the threshold of audibility. Very often, ultrasound is measured (or calculated) in separate frequency bands. The most widespread are octave or 1/3 octave bands with a relatively constant bandwidth. Geometrical average (below in the text for brevity, average) frequencies of these bands are regulated by international and domestic standards. A preferred range of mid frequencies for octave bands: … 125, 250, 500, … Hz; for 1/3 octave bands: … 125, 160,200, 250, … Hz. In addition to these narrow frequency bands, broadband correction is also applied, the form of which is Continue reading
By the angle of sound pickup or directivity, we mean the zone of the possible location of the source of the sound signal, inside of which there is no significant loss in microphone efficiency.
The direction of the microphone is the sensitivity of the microphone to sound, depending on the direction or angle from which the sound comes.
Microphones use several directivity characteristics. Usually they are depicted in the form of polar diagrams, in order to graphically display the sensitivity variations in the 360 degree zone around the microphone, taking the microphone as the center of the circle, and putting the reference point of the angle in front of the microphone.
The radiation pattern shows the dependence of the sensitivity of the microphone to the sound signal on the location of its source.
By direction, there are three main types of microphones: Continue reading