The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 09, 1998
Filed:
Dec. 12, 1995
Chih-Shun Ding, Los Angeles, CA (US);
Other;
Abstract
An improved sound reproduction system employs an amplifier system and a speaker. The system offers greatly improved bass response. The speaker provides two negative feedback signals, one indicative of the current through the speaker voice coil and a second indicative of the velocity of the speaker diaphragm. The velocity signal is provided via the first feedback path to an input of the amplifier of the amplifier system. The current signal is provided by the second feedback path through a bandpass filter to the amplifier input. The velocity measurement may be derived from a second voice coil coupled to the diaphragm, or may be derived from a piezoelectric sensor coupled thereto. The current signal may be derived from the voltage drop across a resistor placed in series with the speaker voice coil.