You are here: Our Products / R&D System / Modules / Linear Parameter Measurement

Linear Parameter Measurement (LPM)

Overview
  • Thiele / Small parameter
  • Identifies linear transducer model
  • Measures suspension creep
  • Single-step measurement with laser sensor
  • Two-step measurement with additional mass or test enclosure
  • Monitors ratio signal to noise + distortion (SNR+D) and noise floor
  • Automatic validity check

This module identifies the electrical and mechanical parameters of electro-dynamical transducers by measuring the voltage and current at the speaker terminals. Using an optional laser displacement sensor, the identification dispenses with a second measurement and avoids problems due to leakage of the test enclosure and mass attachment. This kind of measurement also identifies the parameters of the suspension creep giving more accuracy of the loudspeaker model at low frequencies. The measurement indicates insufficient signal to noise ratio and malfunction operation due to nonlinear effects of the driver or amplifier limiting.

Requirements

It is recommended to use coating spray for micro-speakers and tweeters with transparent and shiny diaphragms. More information.undefined

Added mass perturbation technique

Added mass perturbation technique

Test box perturbation technique

Test box perturbation technique

Laser technique

Laser technique

Multi-tone Measurement

Multi-tone Measurement

Templates coming with the LPM module:

LPM multitone distortion SP1

Multi-tone distortion at high amplitudes (see Application Note AN 16) using standard current sensor 1

LPM Microspeaker T/S (SP2)

Linear parameters of micro-speakers using sensitive current sensor 2

LPM Subwoofer T/S (Sp1)

Linear parameters of subwoofers using standard current sensor 1

LPM Subwoofer T/S (Sp2)

Linear parameters of subwoofers using sensitive current sensor 2

LPM Tweeter T/S (SP2)

Linear parameters of tweeters using sensitive current sensor 2

LPM Woofer T/S (Sp1)

Linear parameters of woofers using standard current sensor 1

LPM Woofer T/S (Sp2)

Linear parameters of woofers using sensitive current sensor 2

LPM Woofer T/S added mass

Linear parameters of woofers using added mass method

Read more

Paper: “Fast and Accurate Linear Parameter Measurement”

Application Note AN16: “Multitone Distortion”

Application Note AN25: “Maximizin LPM Accuracy”



To top