Polk

Baltimore garage startup to American speaker institution

History

Polk Audio was founded in Baltimore, Maryland in 1972 by three Johns Hopkins University graduates: Matthew Polk, George Klopfer, and Sandy Gross. The company started in a garage with a mission to produce quality loudspeakers at affordable prices. The Monitor series (1970s-1980s) established Polk's reputation. The Monitor 7, Monitor 10, and Monitor 12 offered excellent performance per dollar with innovative driver designs and solid construction. Polk pioneered several technologies: - SDA (Stereo Dimensional Array) - Crosstalk cancellation for improved imaging - Dynamic Balance - Driver design optimization - Power Port - Bass reflex enhancement The 1980s brought the flagship SDA-SRS series with elaborate crosstalk cancellation systems. The RTA series offered sophisticated crossover networks and premium drivers. In the 1990s and 2000s, Polk expanded into home theater, car audio, and outdoor speakers while maintaining its core speaker business. The company was acquired by DEI Holdings in 2006 and later became part of Sound United.

Key Facts

Fact	Detail
Founded	1972, Baltimore, Maryland
Founders	Polk, Klopfer, Gross
First Product	Monitor series speakers
Key Innovation	SDA technology
Best Known	Monitor 7, 10, SDA series
Current Status	Part of Sound United

Legendary Products

Polk Monitor 10 (1970s-1980s)

Polk's breakthrough product. The Monitor 10 used two 6.5" woofers, a passive radiator, and a dome tweeter to deliver exceptional bass and smooth highs at an affordable price.

Polk Monitor 7 (1970s-1980s)

A smaller sibling to the Monitor 10 that became equally popular. The Monitor 7 offered much of the Monitor 10's performance in a more compact cabinet.

Polk SDA-1A (1980s)

The flagship of Polk's SDA series, featuring elaborate crosstalk cancellation for holographic imaging. The SDA-1A represented Polk's ultimate statement in stereo reproduction.

Polk RTA-15TL (1990s)

A high-end speaker from Polk's RTA series, featuring sophisticated crossover networks and premium drivers in an elegant cabinet.

Classic Models Reference

Model	Era	Type	Drivers	Key Features
Monitor 4	1970s	Bookshelf	6.5"+1"	Entry Monitor
Monitor 5	1970s	Bookshelf	6.5"+1"	Popular model
Monitor 7	1970s-80s	Bookshelf	6.5"+1"	Classic Monitor
Monitor 10	1970s-80s	Floor	2x6.5"+1"+PR	Dual woofers
Monitor 12	1970s-80s	Floor	2x6.5"+1"+PR	Larger Monitor
SDA-1A	1980s	Floor	2x6.5"+1"+SDA	SDA flagship
SDA-2	1980s	Floor	2x6.5"+1"+SDA	SDA series
RTA 11T	1990s	Floor	3-way	RTA series
RTA 15TL	1990s	Floor	3-way	RTA flagship
LSi9	2000s	Bookshelf	2-way	Later classic

Sound Signature

Polk speakers are characterized by: - Bass punch - Strong low-frequency output - Value engineering - Performance per dollar - Wide dispersion - Room-filling sound - American tuning - Fun, engaging sound - Build quality - Solid construction

Collecting Polk

Vintage Polk gear is valued for: - Monitor series - The classics - SDA series - Holographic imaging - First generation - Original Monitor 7/10 - Working SDAs - SDA cable system functional - Original grilles - Sl2000 tweeter models Most collectible models: - Monitor 10 - The breakthrough - Monitor 7 - Popular classic - SDA-1A - SDA flagship - Early Monitor 10 - First generation

Restoration Tips

Common Polk service items: - Replace electrolytic capacitors (crossover) - Check tweeters (SL2000 often needs replacement) - Refoam woofers if needed - Verify SDA cable connections - Refinish cabinets - Replace grilles if damaged

Competitors & Comparisons

Polk vs Boston Acoustics: Both American; similar positioning Polk vs Infinity: Both value brands; different approaches Polk vs JBL: JBL more professional; Polk more consumer

All Models in Archive (25)

Model 9	1973
AUDIO-MONITOR 15T (Military)	1991
AUDIO-MONITOR 5JR	1984
SDA-2B (Studio)	1988
AUDIO-SRS-1.2TL	1991
Monitor 10 Series II	1990
Monitor 10A	1979
Monitor 4.6 Series 2	1990
Monitor 4A	1984
Monitor 5B	1984
Monitor 7 Series II	1990
Monitor 7	1977
Monitor 7A	1977
Monitor 7C	1979
Monitor 9W	1976
RTA-12	1979
RTA-12C	1984
RTA-8TL	1990
SDA-1A	1985
SDA-1C (Real Wood)	1987
SDA-2B CRS+	1989
SDA-2B (Real Wood)	1989
SDA-CRS	1984
SDA SRS-1.2	1988
SDA SRS-2	1986

Models

Speakers

Polk Audio - American Speaker Innovation

Amplifiers

SDA SRS-2 - 1986

Speakers

Monitor 10 Series II - 1990
Monitor 10A - 1979
Monitor 4.6 Series 2 - 1990
Monitor 4A - 1984
Monitor 5B - 1984
Monitor 7 - 1977
Monitor 7 Series II - 1990
Monitor 7A - 1977
Monitor 7C - 1979
Monitor 9W - 1976
RTA-8TL - 1990