Granted Patent
Utility
US 6,418,231 · App. 09/370,452
High back EMF, high pressure subwoofer having small volume cabinet, low frequency cutoff and pressure resistant surround
Inventor:
Robert W. Carver
Patented Case
View Patent ↗
Granted: Jul 9, 2002
Filed: Aug 9, 1999
Inventor
Robert W. Carver
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.