Altec 811 Horn Family
The Altec 811 series of sectoral exponential horns represents one of the most iconic designs in professional audio history. Best known for its distinctive "snout" appearance in the legendary 811B, this horn family defined cinema sound and remains highly sought after by horn enthusiasts today.
The 811 Series
Altec 811B
The classic "Voice of the Theatre" horn. Massive cast construction, 90° x 40° coverage, and the iconic long-throw snout design. Used in A7 cinema systems and Model 19 home speakers.
- 90° H x 40° V coverage pattern
- 1.4" throat for 288-series drivers
- ~30 lbs cast metal construction
- Straight exponential throat
Design Philosophy
All 811-series horns share common design principles that contributed to their legendary sound:
- Exponential Flare: Precise exponential expansion matches acoustic impedance for maximum efficiency
- Straight Throat: No bends or folds means minimal phase distortion
- Sectoral Pattern: Controlled 90° x 40° coverage fills theater seating while minimizing reflections
- Massive Construction: Heavy cast metal prevents resonance and ensures decades of consistent performance
The Voice of the Theatre Sound
The 811 horn, paired with the Altec 288 compression driver, created the signature "Voice of the Theatre" sound that defined cinema audio from the 1940s through the 1970s. This combination delivered:
- Exceptional dialog intelligibility
- Wide dynamic range from subtle to explosive
- Even coverage throughout theater seating
- Low distortion at high SPLs
- Instantaneous transient response
Historical Significance
The 811 horn was developed during the post-war cinema boom when thousands of theaters needed high-quality sound systems. The design proved so successful that it remained in production for decades and influenced horn design across the industry.
Key historical points:
- Introduced in the late 1940s
- Standard equipment in Voice of the Theatre systems
- Installed in thousands of movie theaters worldwide
- Remained in production into the 1970s
- Still highly sought after by vintage audio enthusiasts
In the Wild
Featured in Resistor Magazine's profile of vintage speaker restorer Iwan Arjanto, who has built multiple pairs of Altec A7 speakers using original 811B horns. The horns are prized for their enduring performance—even decades-old examples can provide exceptional sound quality when properly maintained.
Compatible Drivers
The 811 series horns are designed for Altec's large-format compression drivers:
- Altec 288 - The classic pairing
- Altec 291 series - Later professional drivers
- Various aftermarket diaphragms available for restoration
Modern Use
Today, vintage 811 horns are prized by:
- Horn loudspeaker enthusiasts
- Vintage cinema collectors
- DIY speaker builders
- Professional studios seeking classic Altec sound
Related Horns
- Altec 511B - Compact sibling with same coverage pattern
- 511 Horn Family - The compact alternative
Images
The following sources may have images of this equipment. Always verify license terms and provide proper attribution when required.
Source 1: HiFi Wiki
- Link: HiFi Wiki
- License: Varies - check individual image
- Attribution Required: Yes
- Commercial Use: Unknown - verify on site
- Notes: User-contributed content. Attribution recommended.
Source 2: HiFi Engine
- Link: HiFi Engine
- License: User-contributed manuals
- Attribution Required: Yes
- Commercial Use: Reference only
- Notes: Great for specs/manuals. Request permission for images.
Source 3: Audio Database
- Link: Audio Database
- License: User-contributed
- Attribution Required: Yes
- Commercial Use: Unknown
- Notes: Verify license before use.
Source 4: Radio Museum
- Link: Radio Museum
- License: User-contributed
- Attribution Required: Yes
- Commercial Use: Unknown
- Notes: Attribution required for user photos.
Attribution Notice: This page links to external image sources. When using images from these sources, ensure you comply with their license terms. CC0 images require no attribution. CC BY and CC BY-SA images require attribution.
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Documentation
- Altec Datasheets - Technical specifications
- 811B Driver Page - Detailed information
Related Models
- Altec 1221A
- Altec 3000B
- Altec 600B
- Altec 603
- Altec A4X
- Akai AM-2850 (1975)
- Akai AP-206 (1975)
- Nakamichi BX-1 (1985)
- Acoustic Research research-ar-17 (1978)
- Acoustic Research AR-19 (1994)