Standards issued by the Ministry of Radio, Film and Television of the People's Republic of China

Cable broadcast recording studio design specifications and technical room technical requirements (extract)

GYJ26-86

1. Noise control

1.1 Design standards for noise control

In the frequency range of 125-4000Hz (1/1 octave) In addition to the type of recording studio, the allowable value of the average sound pressure level of indoor noise is also related to the noise of the equipment system itself in the station.

Table 1 Noise evaluation curve of recording studios and other technical rooms

Room name vs. continuous random noise vs. intermittent and pulsed noise

Recording room (for language) NR15-20 (25) NR10-15 (20)

Recording room (for music) NR20-25 NR15-20

Control room, copy room NR25- 30 NR20-25

Broadcasting room NR30-35

＊The values ??in brackets are applicable to TV stations with poor economic conditions.

1.2 Selection of venue

The distance from the recording exterior wall of the broadcasting station (station) to certain noise sources or vibration sources is greater than the requirements in Table 2. Under this condition, reasonable sound insulation and vibration isolation measures should also be determined based on the specific relationship between the noise source and the recording room as well as the frequency and time of noise occurrence and other actual conditions.

Table 2 Minimum distances from external walls of recording and broadcasting to certain facilities

Minimum distances from noise sources and vibration sources to external walls of recording and broadcasting

Train stations, Railway (whistle) 500

Transportation trunk lines 25

Diesel generator room 15

Industrial enterprises, bus stations 300

1.3 on the radio Recording rooms should be reasonably arranged in station (station) buildings according to the following principles:

i. When necessary, non-technical rooms can be used to surround recording rooms and other technical rooms to reduce the risk of external interference. Effect of noise.

ii. The recording studio and its ancillary rooms should be centrally located to facilitate sound insulation.

iii. The recording room should not be directly adjacent to garages, warehouses, metalworking rooms, toilets and other rooms (on the same floor or on the upper and lower floors).

iv. The recording room and its auxiliary rooms should be separated from the basic structure of the main station (station). When the language recording room is built in the main building if necessary, it should be constructed as a "room within a room".

v. The recording studio should be arranged in a location with little traffic to avoid interference from external noise and vibration as much as possible.

vi. Noise reduction and sound absorption treatments should be carried out in places with high noise levels such as foyers and walkways.

1.4 Sound insulation design of the recording studio enclosure

When performing sound insulation design, the center frequency should be 125, 250, 500, 1000, 2000, 4000dB (1/ 1 octave) are calculated separately (1/3 octave if necessary).

The construction quality of the sound insulation walls (including floors and roofs) of the recording studio is closely related to the sound insulation performance. During the design, relevant construction quality requirements should be put forward (for example: brick walls should be filled with grout and all joints should be plastered on at least one side, and all holes should be filled tightly, etc.).

Design and technical requirements for soundproof doors and observation windows

Two soundproof doors must be installed at the entrance and exit of the recording studio. The "sound gate" between the two soundproof doors should be treated with strong sound absorption; the depth of the sound gate should be greater than 1.5m.

Soundproof doors should be designed or selected according to the following requirements:

Table 3 Requirements for sound insulation of single-leaf soundproof doors

Octave center frequency/ Hz 125 250 500 1000 2000 Average

National standard sound insulation door sound insulation capacity 20 25 30 30 32 27.4

Note: The impact of sound leakage such as door gaps has been taken into account in the table.

Soundproof door leaves should be made of a variety of composite structures filled with porous sound-absorbing materials (such as rock wool, glass wool, etc.); the joint between the door seam and the door frame should be sealed; The gap between the door frame and the wall hole should be filled tightly to prevent leakage.

The door body has a strong structure, is not easily deformed, and is easy to open.

Sound insulation doors should be designed or selected according to the following requirements:

The sound insulation of the observation window should meet the requirements specified in Table 4:

Table 4 Standard insulation Acoustic observation window sound insulation capacity

Octave center frequency/Hz 125 250 500 1000 2000 average

National standard observation window sound insulation capacity 40 45 50 54 55 48.5

The observation window should be constructed with multiple layers (usually 2-3 layers) of glass; the layers of glass and their spacing should not all be equal; the window frames between each layer of glass should be sound-absorbing; the gap between the glass and the window frame should be Elastic materials should be used to reduce vibration and sealing measures should be taken; the gaps between the window frame and the window opening must be filled tightly to prevent sound leakage.

The glass on the side of the observation window facing the recording room should be tilted upward 60 degrees.

In relatively quiet conditions, if natural ventilation is used, strict sound insulation measures must be taken on the ventilation windows to ensure that the average sound pressure level of the noise in the recording and broadcasting room meets the requirements of Table 1.

2. The design of the ventilation and air-conditioning machine room should comply with the following regulations

ü The ventilation and air-conditioning machine room can be located outside or inside the main building. When located outside, the outdoor air supply and return ducts should be waterproof, anti-corrosion, heat-preserving and heat-insulating. When located inside, the air-conditioned room and the language recording room should not be directly adjacent, and good vibration isolation measures should be taken.

ü Ventilation and air conditioners should be treated with vibration reduction and sound absorption. If necessary, sound insulation covers should be added to mechanical equipment to control the noise in the machine room below 85db (A).

In the air duct of the ventilation and air conditioning system, regenerative noise caused by excessive wind speed should be avoided. The wind speed should be controlled within the following range:

Table 5 Wind speed m/s at the air duct and return air outlet

Wind speed in the room where the air duct type air outlet is located

Main Air duct--below 10

Branch air duct--below 7.5

Branch air duct--below 5

Send back to the entrance recording room 1.0 -Below 1.5

Below 3.5 in the control room and copy room

Below 3.5 in the broadcast room and tape library

In the studio (near the microphone), The free flow velocity of air should not be greater than 0.5m/s.

3. Sound quality design

General requirements for sound quality design

The indoor area of ??a language recording studio for 1-2 people should be 12-16 square meters m2, the area of ??a music recording studio for a band of less than 20 people should be 80-120 m2.

Table 6 Dimensions of recording studio m

Recording room type length, width and height

Language recording room 12m2 3.90 3.10 2.80

4.50 3.60 3.00

Music recording room 80m2 11.40 7.20 4.50

Music recording room 120m2 14.20 8.60 5.50

When the recording room cannot comply with the dimensions recommended in Table 6, the length, width and height of the recording room can be calculated according to the following proportions:

Small recording room L ：W：H＝1.6：1.25：1.0

Small recording studio L：W：H＝1.6：1.25：1.0

General recording studio L：W：H＝2.5 : 1.6: 1.0

Low and long-top recording studio L: W: H＝3.2: 2.5: 1.0

Slender recording studio L: W: H＝3.2: 1.25 : 1.0

The recording studio shall not have a square cross-section or a shape with curved walls or domed roofs.

Selection of reverberation time in the recording studio

The reverberation time in the recording studio is determined by the type of program, the volume of the recording studio and the recording method.

Recommended values ??for the reverberation time and frequency of each recording room are shown in Table 7:

Table 7 Reverberation time and frequency characteristics of the recording room

Reverberation of recording room types Time (S)

1/3 octave center frequency (Hz)

100 125 250 500 1000 2000 4000 8000

Language recording room 12m2 0.30 0.30 0.30 0.30 0.30 0.30 0.30 ---

Language recording room 16m2 0.30 0.35 0.40 0.40 0.40 0.40 0.40 ---

Music recording room 80m2 0.60 0.60 0.60 0 .60 0.60 0.60 0.60 0.60

Music recording studio 120m2 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90

Finally, let me summarize: if you want good sound insulation, you must make a cavity, and the live broadcast room must also There is the problem of controlling reverberation time.

The principle of sound insulation is that sound will vibrate and reflect when passing through different media. As the sound energy is consumed, the noise will be smaller!