Multi-Tone Distortion (MTD)
Optional Modules for the KLIPPEL QC Framework
Features and Benefits
- Multi-tone broad-band stimulus (music-like)
- Acoustic „finger print“ testing of speakers and audio systems (max SPL & distortion)
- Fundamental, level and transfer function
- Multi-tone distortion (MD) includes all distortion (HD, IMD)
- Relative MD and Total MD Ratio for simple limit setting
- Robust towards room influence
- Compliant to IEC60268-21
- Dedicated to fast-end-of-line testing
- Ensures overall consistency of production
The Multi-Tone Distortion (MTD) task is an add-on to the QC end-of-line test system. Closely related to the MTON module with focus on R&D applications, the MTD is based on multi-tone test signals.
In contrast to pure sinusoidal sweep excitation (such as SPL Task), multi-tone stimuli do not only excite harmonic distortion (HD) but also intermodulation distortion (IMD). Therefore, multi-tone distortion provides a much more comprehensive distortion pattern than harmonics alone. Due to the sparse broad band excitation, it is not always possible to identify distinct root causes and symptoms in multi-tone distortion, but it provides a more realistic distortion finger print than pure HD and IMD tests since operation conditions are closer to the final application with music. Therefore, the MTD is highly valuable to verify audio quality and max SPL handling in quality control.
Specification
Standard Measurements
Test Objects
- Any (except Suspension Parts)
Requirements
Test Hardware
- Klippel Analyzer 3 (KA3) or
- Production Analyzer (PA) or
- 3rd party audio interface (sound card)
License Dongle (USB)
PC
Software
- QC Standard Software 6.6 or above
- QC Stand-alone Software
- QC in R&D
Accessories
- Microphones
- Power Amplifier
- KA3 Amplifier Card or
- KA3 QC Card or
- 3rd party amplifier
Application
Application Notes
Templates
dB-Lab Operation Template: QC Multi-tone Distortion (MTD)
Related Information
Other Modules of the QC System
- Spectrum Analysis (SAN)
A-weighted SPL and distortion with/without noise generator or user-defined stimulus for noise & vibration or audio system testing - Sound Pressure Task (SPL)
Measurement of frequency response, THD and Rub & Buzz - Sound Pressure and Impedance Task (SPL-IMP)
Combined acoustic and electric measurement dedicated to fast QC testing
Related Products
- 3D Distortion Measurements (DIS)
Module performs a series of steady-state measurements by using a single- or two-tone excitation signal varied in frequency and voltage - Multi-Tone Measurement (MTON)
Module provides sound pressure level (SPL) based characteristics using a multi-tone stimulus
- Tone Burst Measurements (TBM)
Peak SPL measurements using tone burst signals - Transfer Function Measurement (TRF)
Measurement of transfer function and harmonic distortion
Literature and Papers
- Voishvillo, et. al. , “Graphing, Interpretation, and Comparison of Results of Loudspeaker Nonlinear Distortion Measurements,” J. Audio Eng. Society 52, No. 4 pp. 332-357 (Apr. 2004)
- W. Klippel: Physical and Perceptual Evaluation of Electric Guitar Loudspeakers
Standards
International Electrotechnical Commission
IEC 60268-21 Sound system equipment - Part 21: Acoustical (output-based) measurements