Room acoustics

src: i.ytimg.com

Acoustic space describes how sounds behave in enclosed spaces.

Video Room acoustics

Zona

The way sounds behave in a room can be broken down into about four different frequency zones:

• The first zone is below the frequency that has the wavelength twice the longest length of the room. In this zone, the sound behaves very much like a static air pressure change.
• Above the zone, until the wavelength is proportional to the dimension of the room, the resonance space predominates. These transition frequencies are known as Schroeder frequencies, or cross-over frequencies and these distinguish low frequencies that create standing waves in small spaces of medium and high frequencies.
• The third region that extends about 2 octaves is the transition to the fourth zone.
• In the fourth zone, the voice acts like a ray of light reflecting around the room.

Maps Room acoustics

Natural mode

Sound waves have reflections on the walls, floor and ceiling of the room. The incident wave then has an interference with the reflected. This action creates standing waves that produce nodes and high pressure zones.

In 1981, to solve this problem, Oscar Bonello, professor at the University of Buenos Aires, formulated a capital density concept solution that used the concepts of psychoacoustics. Called "Bonello Criteria", this method analyzes the first 48 space modes and plots the number of modes in each one-third of an octave. The curves increase monotonically (each one-third of an octave must have more modes than the previous one). Another system for determining the correct spatial ratios has recently been developed

src: www.neumann.com

Room reverberation

After determining the best dimension of the room, using the capital density criterion, the next step is to find the exact buzzing time. The most appropriate buzzing time depends on the use of the room. About 1.5 to 2 seconds is required for opera houses and concert halls. For studio broadcasting and recording and conference rooms, values ​​under one second are often used. The recommended buzz time is always a function of room volume. Some authors provide their recommendations A good approach to Broadcasting Studios and Conference Rooms is: TR [1kHz] = [0.4 log (V 62)] - 0.38 TR in seconds and V = volume of space in m ³ ideal RT60 should have the same value at all frequencies from 30 to 12,000 Hz. Or, at least, it is acceptable to have a linear rise from 100% at 500 Hz to 150% to 62 Hz

To get the desired RT60, some acoustic material can be used as described in some books. The valuable simplification of the task was proposed by Oscar Bonello in 1979 It consists of using standard 1 m ² acoustic panels hanging from the walls of the room (only if the panels are parallel). These panels use a combination of three Helmholtz resonators and wood resonance panels. This system provides large acoustic absorption at low frequencies (below 500 Hz) and reduces at high frequencies to compensate for typical uptake by people, lateral surfaces, ceilings, etc.

src: blog.teufelaudio.com

See also

• Acoustic boards
• Acoustic space
• Acoustics
• Anechoic space
• Architectural acoustics
• Digital space correction
• Noise control
• Reverberation
• Sound checking
• Whispering Gallery

src: 4.bp.blogspot.com

Note

src: i.ytimg.com

References

Source of the article : Wikipedia