Altec 511 Horn Family

Name: Altec 511 Horn Family
Brand: Altec

The Altec 511 series of sectoral exponential horns delivers the classic Altec "Voice of the Theatre" sound in a more compact package than the larger 811 series. Featuring the same iconic 90° x 40° coverage pattern, the 511B offers professional horn performance in a manageable size for both commercial and home applications.

The 511 Series

Altec 511B

The compact classic. Same legendary Altec horn sound as the 811B but in a smaller, lighter package. Ideal for home horn systems and smaller commercial installations where the full-size 811B would be impractical.

90° H x 40° V coverage pattern
1.4" throat for 288-series drivers
17.75 lbs, compact design
Straight exponential throat

511 vs 811: Choosing the Right Horn

Both the 511 and 811 series deliver classic Altec horn character, but with different applications in mind:

Feature	511B	811B
Coverage Pattern	90° x 40°	90° x 40°
Weight	17.75 lbs	~30 lbs
Dimensions	Compact	Large
Recommended Drivers	288 series	288 series
Best For	Home, small venues	Cinema, large venues

Design Characteristics

The 511B shares the same fundamental design principles as its larger 811B sibling:

Exponential Flare: Precise exponential expansion for maximum efficiency
Straight Throat: No phase-distorting bends or folds
Sectoral Pattern: Wide horizontal, controlled vertical coverage
Cast Construction: Durable, resonance-free build quality

In the Wild

As noted in Resistor Magazine's restoration profile, vintage speaker specialist Iwan Arjanto describes the 511B as his entry point into horn-loaded speakers. After building his own pair of A7-style speakers using the compact 511B horns, he eventually moved on to full-size 811B implementations for customers.

The 511B offers an accessible way to experience classic Altec horn sound without the space requirements of the larger 811 series.

Applications

The 511B excels in situations where space is limited but horn performance is desired:

Home hi-fi horn systems
Small theater installations
Studio monitoring
Vintage audio projects
Horn enthusiast learning builds

Compatible Drivers

The 511 series uses the same driver mounting as the 811 series:

Altec 288 - The classic professional driver
Altec 291 series - Later variants
Compatible with standard 1.4" throat mounting

Historical Note

While the 811B became the iconic "Voice of the Theatre" horn installed in thousands of cinemas, the 511B served an important role as a more practical alternative for smaller venues and home installations. Both horns share the same sonic DNA that defined the Altec sound.

Related Horns

Altec 811B - The larger classic sibling
811 Horn Family - The full-size alternative

Images

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Source 1: HiFi Wiki

Link: HiFi Wiki
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Source 2: HiFi Engine

Link: HiFi Engine
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Source 3: Audio Database

Link: Audio Database
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Source 4: Radio Museum

Link: Radio Museum
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