Dear All,
With this email, I would like to announce the release ofSoundEasy V23.
There are 25 new features / improvements and a couple of bugfixes. Many of you will recognize your inputs, so thank you for yourcontributions. The following are the main new features:
Item 4 requires further comment. Correct determination ofthe minimum-phase phase response of a loudspeaker driver has been often viewedas an impossible task. SE V23 takes one step further in providing a solution tothis dilemma. The method was developed to exemplify the following logic.
Loudspeakers are known to be minimum-phase devices withintheir operating frequency range. Therefore, their SPL and Phase response aremathematically locked via Hilbert-Bode Transform (HBT), even though thisrelationship breaks down within the break-up region. This characteristics allowus to construct a simple band-pass model of the loudspeaker, using measured SPLas a template, from which we can instantly obtain minimum-phase phase responseof the model. Since we are mainly interested in the asymptotic slopes of the SPLresponse, the actual model does not have to be very complex. Afteroptimization, the band-pass model provides a template for the HBT parameters,such as the asymptotic slopes of the SPL and at the same time guides thelocation of the FFT window for converting measured SPL into minimum-phaseSPL/Phase of the measured driver.
The above approach is facilitated by employing curve-fittingalgorithm to optimize the fitting accuracy of the band-pass model to themeasured SPL. The algorithm manipulatesseveral parameters of the band-pass model to minimize the error functionobjectively and therefore is independent of the operator’s judgement orspeculations. If correctly executed, the band-pass model is the best fit tothe measured SPL, thus providing the most accurate minimum-phase phase responsepossible. From here, the acoustic centre, “time-of-flight” and location of FFTwindow can be determined.
For your upgrade, please contact me directly. Bodzio Software
Best Regards,
Bohdan
With this email, I would like to announce the release ofSoundEasy V23.
There are 25 new features / improvements and a couple of bugfixes. Many of you will recognize your inputs, so thank you for yourcontributions. The following are the main new features:
- New measurement method for evaluation Non-Coherence Distortion of a loudspeaker, using music or noise as the test signal. The method provides continuous NCD vs. frequency curve and also Total NCD figure.
- New impedance measurement method for large signal excitation. This method cam be used to measure impedance under typical operating conditions, which typically exceed the standard 1W test signal.
- Implemented Semi-Inductance impedance model across the modelling functions and also a method for extracting S-I parameters from measured data curve. The S-I model is more accurate than previously implemented models.
- Curve fitting method for optimizing SPL match between Band-Pass loudspeaker model and measured SPL for the purpose of determining the minimum-phase response of the measured driver and the location of the FFT window.
- Display CSD difference between two impulses. Both CSD waterfalls are saved to HD for further comparisons.
Item 4 requires further comment. Correct determination ofthe minimum-phase phase response of a loudspeaker driver has been often viewedas an impossible task. SE V23 takes one step further in providing a solution tothis dilemma. The method was developed to exemplify the following logic.
Loudspeakers are known to be minimum-phase devices withintheir operating frequency range. Therefore, their SPL and Phase response aremathematically locked via Hilbert-Bode Transform (HBT), even though thisrelationship breaks down within the break-up region. This characteristics allowus to construct a simple band-pass model of the loudspeaker, using measured SPLas a template, from which we can instantly obtain minimum-phase phase responseof the model. Since we are mainly interested in the asymptotic slopes of the SPLresponse, the actual model does not have to be very complex. Afteroptimization, the band-pass model provides a template for the HBT parameters,such as the asymptotic slopes of the SPL and at the same time guides thelocation of the FFT window for converting measured SPL into minimum-phaseSPL/Phase of the measured driver.
The above approach is facilitated by employing curve-fittingalgorithm to optimize the fitting accuracy of the band-pass model to themeasured SPL. The algorithm manipulatesseveral parameters of the band-pass model to minimize the error functionobjectively and therefore is independent of the operator’s judgement orspeculations. If correctly executed, the band-pass model is the best fit tothe measured SPL, thus providing the most accurate minimum-phase phase responsepossible. From here, the acoustic centre, “time-of-flight” and location of FFTwindow can be determined.
For your upgrade, please contact me directly. Bodzio Software
Best Regards,
Bohdan
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