How to measure the frequency characteristics of a compact speaker simply and quickly in a mobile phone etc.
Example3 : Offline analysis with the data saved by the sound level meter
(using LA-7500, a transmitter, OC-2000 series, and a PC)
Output the sine sweep signal from a signal transmitter, then record the sound from the speaker with the LA-0704 sound recording function installed in the LA-7500 into a high speed SD card at WAV format (64 kHz, 16 bit AD conversion).
Playback the WAV format file with the OS-2720 FFT Analysis package of the OS-2000 series on a PC. Analyzing the AC out signal of the sound level meter with the peak average function of the power spectrum, you can display the X axis as frequency, Y axis as sound pressure level.
(Note）Up to 2 GB of LA recording data when reading with the OS-2000 series.
Recording time : 4.5 hours in 2 GB (when 16 bit)
: 3 hours in 2 GB (when 24 bit)
System configuration
| Model name | Product name | Remarks | |
|---|---|---|---|
1 |
LA-7500 | Class 1 Sound Level Meter | Measurement frequency range : 10 Hz to 20.0 kHz |
| 2 | LA-0704 | Sound recording function | Recording format : WAV file format |
3 |
AG-3401 | Microphone extension cable | 5m |
4 |
OS-2720 | FFT Analysis package | OS-2000 series |
Revised:2018/10/31
