5

DS1126DB1

CDB7121P

2.2 Free field acoustic test

2.2 Free field acoustic test

Recommendations for accurate free field measurements are as follows:

•

Ensure calibrated test equipment is used for making measurements

•

Ensure CDB7121P acoustic port hole and reference mic are facing to the incoming sound pressure

•

Ensure CDB7121P and reference mic are placed close together with minimum placement error

•

The CDB7121P may be trimmed along the ‘Trim line’ to improve accuracy

•

Use a suitable test microphone—a free field reference microphone is recommended

•

Measurements should be performed within an anechoic environment

Figure 2-2. Free field test setup with CDB7121P

Free Field

Reference Mic

Test

Speaker

Power

Anechoic Chamber

Sound

Pressure

Level

Standard Test Equipment

Test Point

Connections

CDB7121P