Audio/Acoustic PB-2

Test Chamber Specification

Issue by: Justin Chen

E-mail: Justin@obopro2.com

TEL+886-3-358-5399

Contents 1. Introduction

2. Mechanical & Electrical Specification

3. Acoustical Specification

3-1 Basic Raw Materials

3-2 Acoustic Performance

3-2.1 Designs Anticipated

3-2.2 Test Results

3-2.3 Test Equipments

1. Introduction:

The PB-2 test chamber is special designed for the acoustic testing of consumer products.

(As like: Headphone/Headset/Tablet/NB/PMP/Smart Phone…etc) The chamber can provide

a reliable and stable test environment. There is artificial mouth, ear or microphone integrated

inside for advanced acoustic analysis. There are several reserved connection interface for

audio equipment as like USB port and one I/O port is reserved for automatic control. The

noise shielding ability is different by the building material and mechanical design. Please see

the related document for more detail.

2. Mechanical & Electrical Specification Outside Dimension: L:70cm * W:80cm * H:60cm

90 cm (Max Height when Box Open )

Inside Dimension: L:55cm * W:65cm * H:45cm

Net Weight: ~ 280Kg

Construction: The Aluminum alloy steel plate

Power Request: 100VAC~230VAC /3A

Sound Insulation Ability: > 40dB(A-Weighting) SPL ref. 20uPa

Operating Working Space: ~120 cm (W) X 120 cm (L)

Air compressor Request 6 Kg/ cm^2

Interfaces for Connection BNC Audio Connectors x 10 sets

USB Port x 2 sets

Phone Jack x 2 sets

RJ-45 Ethernet Port x 1 set

D-Type 9 pin x 1 set

3. Acoustical Specification

3-1 Basic Raw Materials:

A. The Aluminum alloy steel plate adds the base varnish ~ 10mm

B. Mineral Fiber Acoustic Board ~ 10mm

C. SBR(Styrene Butadiene Rubber) foaming board ~ 10mm

D. Sound Absorption: BASF Basotect (Color White) ~50mm

Material data information below as :

29/06/2008 INTERNAL 1

Density密度9,5 ± 1,5 kg/m³ EN ISO 845

0,61 ± 0,1 lb/ft³

compressive stress at 10%

4 - 20 kPa DIN 53 421

0,73 - 2,9 lb/in²

coefficient of sound absorption 吸音率90 - 95 % DIN 52 215

t = 50 mm [2 inch]

f = 2000 Hz

Physical properties of Basotect®

Basotect 基本物性

29/06/2008 INTERNAL 2

Physical properties of Basotect®

Basotect 基本物性

properties units test method values

density kg/m³ EN ISO 845 9.5 ± 1.5

lb/ft³ 0.7 ± 0.1

compressive stress kPa DIN 53421 4 - 20 at 10% compression lb/in² 0,73 - 2,9

max. intendation force N BASF-method 45

tensile strength kPa DIN 53571 > 120

Elongation at break (tensile) % DIN 53571 > 10

compressive strengthat 40% compression kPa DIN 53577 6 - 20

thermal conductivity [10°C] W/mK DIN 52612 < 0.035[50°F] BTUin/hft²°F < 0.24

compression set50% / 23 °C / 72h % DIN 53572 10 - 3550% / 70 °C / 22h 5 - 30

29/06/2008 INTERNAL 3

properties units test method values

diffusion resistance factor µ DIN 52615 app. 1-2

acoustic absorptiont = 2.0 in / f = 2000 Hz % DIN 52215 > 90t = 1.6 in / f = 2000 Hz DIN 52212 > 0.9

length specific air flow resistance kNs/m4 DIN EN 29053 8 - 20

long term application 長時間工作溫度temperature °C app. 200

°F app. 392

Physical properties of Basotect®

Basotect 基本物性

29/06/2008 INTERNAL 4

properties unit test method values

fogging % DIN 75210, meth. A > 90mg DIN 75210, meth. B < 0,5

fire performance DIN 4102 B1

UL 94 94 V-0

94 HF-1

NF P 92-501 M1

FAR 25.855 a1 fulfilled

ASTM E662-83 fulfilled

ABD 0031 fulfilled

BSS 7238 / 7239 fulfilled

FMVSS 302 fulfilled

BS 476, part 6/7 class 0

CNS 6532 (Taiwan) fulfilled

The given values are guidlines only based on screening tests.

Physical properties of Basotect®

Basotect 基本物性

Toxic Smoke Test

In general, it discharge

toxic smoke while Temp.

arrive to 250℃ (482℉).

“Basotect” withstand to

350℃(662℉)

29/06/2008 INTERNAL 5

Sound absorption of Basotect®

DIN 52 215 吸音測試

frequency in Hz

sound absorption coeff. in %

t = 60 mm

0

20

40

60

80

100

120

125 200 315 500 800 1250 2000 3150

t = 20 mm

t = 40 mm

29/06/2008 INTERNAL 6

Sound absorption of Basotect®

DIN 52 212 吸音測試

frequency in Hz

sound absorption coeff. in %

0

20

40

60

80

100

125 200 315 500 800 1250 2000 3150

t = 30 mm

t = 10 mm

t = 50 mm

t = 100 mm

29/06/2008 INTERNAL 7

Sound absorption of Basotect® (Plate vs Pyramid)

ASTM E1050-90 / Test By Industrial Technology Research

Institute

-0.1

0.1

0.3

0.5

0.7

0.9

1.1

126 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000

頻率Hz

正向

入射

吸音

率

30mm

P30mm40mm

P40mm50mm

P50mm80mm

29/06/2008 INTERNAL 8

Physical properties of Basotect®

Basotect

thermal conductivity

10C < 0,035 W/mK DIN 52612

50F < 0,24 Btu in/hft² °F

0.0296 kcal/m.hr.°C (3cm) CNS 7333 0.0306

kcal/m.hr.°C (4cm) CNS 7333 0.0323

kcal/m.hr.°C (5cm) CNS 7333

flammability

B1 : DIN 4102 / class 0 : BS 476, part 6/7

M1 : NF P 92-501 / 94 V-0 : UL 94

ok : Boeing BSS 7238/39

(e.g. with Calcium silicate board All Pass CNS-6532 Bears burns Third-

level)

temperature at permanent use

150 °C [300 °F]

3-2 Acoustic Performance

3-2.1 Designs Anticipated:

A. Sound Insulation Ability ≧ 40dB(A)

B. Internal Noise(when outside noise≦ 70dB(A) ≦20dB(A)

C. 3KHz to 20KHz Cut off High Frequency ≦ 10dB SPL ref.20uPa

D. Wedge Sound Absorption cut off frequency ≦ 1.7KHz

E. Floating Nature Frequency ≦ 15Hz

F. RF Shielding Ability for Bluetooth 2.4GHz ≧ 30dBm

3-2.2 Test Results:

A. Chamber Inside Noise 19.87dB(A-Weighting) FFT & LEQA Mode.

(Office Noise 60~70dBA Condition)

B. Sound Insulation Ability > 40dBA

Sends out the stable Pink Noise ~ 80dBA

Internal Noise ~38.92dBA (Closed door)

3-2.3 Verify with a list of Equipments:

1. IEA EA2 : Electro-Acoustic Integrated System.(CLIOQC Version 10.03)

2. B&K 4231: Sound Level Calibrator.

3. B&K 5935: Microphone Power Supply

4. B&K 4190: 1/2 inch Free Field Microphone System

5. TANNOY 800 : Coaxial Source Reference Loudspeaker