Speaker/Transducer Testing

Introduction

(click to enlarge) RT-Speaker Main Menu

Key features for a modern, state-of-the-art test system are speed, simplicity, reproducibility and automation in a factory environment. The PureSound speaker test system exactly answers these needs. The key element is the unique Rub&Buzz defects analysis with a 100% correlation to the human ear. It replaces the subjective human ear perception against an objective, reliable and repeatable test feature. The PureSound speaker test system is based on the RT-2M high-speed audio analyzer and operated via the PC-based turnkey production software RT-Speaker. It is tailored for the total quality control of single components, pre-assembled parts or finished products. Electro-acoustical transducers naturally bear a particularly high error rate. Sorting out faulty devices in an early production stage with the PureSound speaker test system increases the overall yield and reduces the cost of waste material and optimizes the quality of the manufactured goods.

 

Key-Features:

Rub & Buzz analysis: Rubbing voicecoil (click to enlarge)

Speed Test cycle time is typically 1.5 - 2.5 seconds excluding handling. Accuracy The audio analyzer is based on reliable technologies providing accurate and consistent test results. Unique Rub&Buzz Detection Superior Rub&Buzz defects detection with a 100% correlation to the human ear. Objective Rub&Buzz testing replaces subjective golden ears. Noise Immunity Maximum performance in noisy production environment using dedicated technologies. Automation Suited to automated production lines with PLC interface, barcode reader and data logging (e.g. Cpk, Ppk). Multi-Channel Operation Two or more DUT’s can be tested automatically in sequential order without any operator control.

 

Flexible Parameter and Tolerance Setting

Rub & Buzz analysis: Loose particles (click to enlarge)

The key element is the Rub&Buzz test technology with an unique and reliable defects analysis. The cycle time is typically 1.5 - 2.5 seconds for a complete speaker test including the outstanding Rub&Buzz analysis. Measurement Parameters: Frequency Response Distortion THD, THD+N, k2, k3, k4, k5, Sum (k3-k5) Impedance Response Resonance Frequencies f0 Sound Pressure Level dBSPL Speaker Polarity Rub&Buzz defects analysis with a 100% correlation to the human ear Thiele/Small Parameters DC Resistance

 

Calibration and Recording of Reference Data

Recording of Reference Data (click to enlarge)

The main menu guides the production administrator through the basic system configuration on to the test parameter settings, which are contained in a single “Project“ folder. After an automated calibration sequence a representative set of one or more “Golden Samples” can be recorded. The unique tolerance management derives its tolerance criteria automatically and supports up to five different quality clusters, which may be user-defined in any language, such as “Excellent”, “OK”, “Acceptable”, “Class 3” and “Reject”. This enables the manufacturer e.g. to charge a premium for selected “Excellent” products or match speaker pairs for stereo applications.

 

Speaker Production Testing

Production Testing Overall View (click to enlarge)

A simple PASSED/FAILED readout or a detailed view of all measured speaker parameters is provided to the operator. System integration into existing high volume production lines and the connection to host controllers is very simple. The patented measurement algorithms have been optimized for factory noise immunity. Measurements can be started by an external button or automatically as the speaker is connected. Common available DIO-cards and the LPT-port are integrated for automated operation, such as Connection to external PLC Test result indication to the operator External pre- or post-test actions independent of test result Automated splitting of PASSED/FAILED samples Individual bin splitting of different FAILED samples