2 771 518

Sziklai

Frequency band separation amplifier

November 1956

2 802 054

Corney

Sound reproducing apparatus

August 1957

3 457 370

Boner

Impedance correcting networks

July 1969

3 657 480

Cheng et al

Multi channel audio system with crossover network feeding separate amplifiers for each channel with direct coupling to low-frequency loudspeaker

April 1972

3 727 004

Bose

Loudspeaker system

April 1973

3 814 857

Thomasen

2-way loudspeaker system with two tandem-connected high-range speakers

June 1974

3 838 215

Haynes Jr

Speakers and crossover circuit

September 1974

4 015 089

Ishii et al

Linear phase response multi-way speaker system

March 1977

4 031 321

Bakgaard

Loudspeaker systems

June 1977

4 198 540

Cizek

Compensated crossover network

April 1980

4 229 619

Takahashi

Method and apparatus for driving multi way speakers

October 1980

4 243 840

Kates

Loudspeaker system

January 1981

4 282 402

Liontonia

Design of crossover network for hifi

August 1981

4 430 527

Eberbach

Loudspeaker crossover delay equaliser

February 1984

4 475 233

Watkins

Resistively damped loudspeaker system

October 1984

4 525 857

Orban

Crossover network & clipper

June 1985

4 589 135

Baker

Zero phase shift filtering

May 1986

4 769 848

Eberbach

Electroacoustic network delay HF

Sep 1988

4 771 466

Modafferi

Multidriver loudspeaker apparatus

Sep 1988

4 897 879

Geluk (B&W)

Multi-way loudspeaker system

January 1990

4 991 221

Rush

Active speaker system and components therefor

February 1991

5 129 006

Hill

Electronic audio signal amplifier

July 1992

5 185 801

Meyer

Correction circuit and method for 2-way speaker

February 1993

5 327 505

Kim

Multiple output transformers network for sound reproducing system July 1994

5 568 560

Combest

Audio crossover circuit

October 1996

5 930 374

Werrbach

Phase coherent crossover

July 1999

6 115 475

Alexander

Capacitor-less crossover network for electro-acoustic loudspeakers

Sep 2000

6 381 334

Alexander

Series-configured crossover network for electro-acoustic loudspeakers

April 2002

6 707 919

Koval

Driver control circuit

March 2004

6 854 005

Thiele

Crossover filter system and method

February 2005

7 085 389

Modafferi

Infinite slope loudspeaker crossover

August 2006

7 876 920

Harvey

Active crossover for use with multi-driver headphones

January 2011

8 391 535

Harvey

Active crossover for use with multi-driver in-ear monitors

March 2013

9 258 646

Hillman

Self-powered audio speaker having modular components

February 2016

Patent Applications

20120213386

Knight

Audio crossover system and method

August 2012

20140219480

Collins

Phase-Unified Loudspeakers: Parallel Crossovers

August 2014