Hi-2 Weighted Harmonic Distortion (Hi-2)
Add-on to the SPL Task and Optional Module for the KLIPPEL QC Framework
Features and Benefits
- Fast measurement of Hi2 distortion (also called „BLAT“)
- Add-on to SPL task
- Using sine chirp
- Standardized or user defined limits
- Compatible to DIS-Pro
- Integrated in SPL task
- Conform to automotive standard
- Sensitive distortion measurement of higher harmonics
Hi-2 distortion (also called “Blat” distortion since detected defects sound like a “blat” on bass signals) are calculated from higher order harmonic distortion. Such harmonics are weighted in a special way to emphasize defect symptoms of unacceptable speaker behavior. The cause of the distortion was determined to be a rapid increase in suspension stiffness at large cone excursion.
This distortion measure is related to Rub&Buzz symptoms, which also indicates abnormal sound. However, Hi-2 distortion are characterized by lower harmonics than typically Rub&Buzz distortion show.
The SPL Task uses sine chirps for Hi-2 distortion measurement and can therefore measure this symptom in very short time. Hi-2 distortion may also be measured by the DIS Pro module using steady state sine tones.
- Hi-2 distortion was developed for automotive woofer, subwoofer
- applicable also to other types, especially low frequency drive units
Other Modules of the R&D System
Other Modules of the QC System
Non-official standards by automotive industry