Nonlinear Residual Analyzer (NRL)
Active module (pre-release status) and available from dB-Lab 212
Features and Benefits
- Spectrum analyzer with an arbitrary stimulus (e.g., music)
- Monitoring of time-variant and time-invariant linear transfer function
- Distortion separation (harmonic, intermodulation, rub & buzz)
- Listen to isolated distortion
- Applicable to any audio system and transducer
The Nonlinear Residual Analyzer (NRL) is a tool dedicated to measuring active or passive audio systems with music, speech, or any other test signal. Based on the monitored signals, the NRL determines the linear transfer function of the device under test adaptively and separates the linear response from distortion components (e.g., non-linear or Rub&Buzz). This combination of modern measurement and listening techniques (auralization) helps to understand and evaluate the sound quality of your audio product.
Identification and Monitoring
The NRL can be operated as a spectrum analyzer and beyond that, the transfer function between two signals is identified adaptively. That means, if the transfer function changes during the test, the modeling adjusts itself. This can be used to determine the long-term properties of loudspeaker systems.
Applications include the investigation of heating effects, the drift of transfer function, and durability tests.
Distortion Separation and Auralization
In addition to the transfer function, the NRL will separate a residual signal from a measurement based on a linear modeled signal.
This residuum will contain all the nonlinear effects of the provided DUT and can be listened to. The residuum can also be amplified and added back to the linear modeled signal. Listening to this will provide an intuitive picture of how different nonlinear effects influence sound quality.