Automotive sound system
CA 1293931 C · Owner: Field, Richard C. · Inventors: Field, Daniel J.; Mccorkle, David P.; Field, Richard C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An automotive sound system has a pair of front channels and a pair of rear channels. The channel are coupled to a source of program material. Each channel also has an input stage a, second stage and multiple, independently selectable circuits providing equalization poles. One or more of the multiple equalization pole-providing circuits is independently and selectively coupled to the input stage and to the second stage. Each channel has a filter having a variable lower corner frequency coupled to the second stage, and has a control input terminal. Each channel also has an amplifier coupled to the variable corner frequency filter, a transducer coupled to the amplifier and a low-pass filter …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted January 7, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 7, 2009.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.