Circuit and method for compensating low frequency band for use in a speaker
US5226089A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1991 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | Mar 29, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit and method are disclosed for improving low frequency characteristics in a speaker by detecting the motion of a vibration system of the speaker to be fed back to the vibration system. The circuit detects the motion signal by bridge-balancing the input and output signals of the speaker to detect a voltage difference therebetween. Low frequency reproduction characteristics of the speaker are compensated by reducing lowest resonance frequency characteristics of the speaker and at the same time compensating intrinsic impedance characteristics thereof. The audio signal being reproduced is detected by bridge-balancing the output of the speaker, and dynamic impedance caused by the vibration system is detected by calculating the difference between the detected audio signal and an audio signal applied to the speaker. The motion of the vibration system is converted into acceleration motion at a lowest resonance frequency of the speaker and the motion of the vibration system is converted into a speed value to change resonance sharpness of the speaker. Thereafter, signal adding is performed such that a difference of converted acceleration motion is negatively fed back while a converte…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.