Altec Voice of the Theatre A7

Name: Altec Voice of the Theatre A7
Brand: Altec

1947 - 1970s

The Voice of the Theatre A7 is arguably the most iconic cinema speaker ever created. Introduced in 1947, this massive two-way horn-loaded system defined the sound of movie theaters for decades and remains a coveted collector's item for high-efficiency audio enthusiasts.

Specifications

Type	2-way, combination horn/bass-reflex cinema loudspeaker
Low Frequency Driver	Altec 515B 15" woofer (later 515-8G)
High Frequency Driver	Altec 288 compression driver with 811B sectoral horn
Crossover Frequency	800 Hz
Nominal Impedance	8 Ω or 16 Ω
Power Handling	50W continuous, 100W program
Sensitivity	104 dB/W/m
Frequency Response	40 Hz - 16 kHz
Dimensions	42" W x 26" H x 24" D (with baffles)
Weight	Approximately 140 lbs per speaker

Drivers Used

Woofer: 515B or 515-8G - 15" high-efficiency woofer with Alnico V magnet
Compression Driver: 288 series - 1.75" diaphragm compression driver
Horn: 811B - 90° x 40° sectoral horn

Design Overview

The A7 is a combination horn and bass-reflex design. The 515 woofer is mounted in a large vented enclosure that provides extended bass response while maintaining high efficiency. The 288 compression driver on the 811B horn provides wide coverage and excellent intelligibility for dialog.

Early A7 models featured side wings or baffles that helped control dispersion and increase bass loading. Later "Voice of the Theatre" branded models were available without these side wings for home use.

Variants

A7-500: Original version with 288 compression driver
A7-500-8: 8-ohm version with updated components
A7-500-8E: Later export version
A7-8: Home version without side wings

Historical Context

The Voice of the Theatre series was developed to address the needs of the booming post-war cinema industry. The A7 quickly became the industry standard, installed in thousands of movie theaters worldwide. Its exceptional efficiency (over 100 dB sensitivity) meant it could fill large spaces with modest amplifier power.

Today, A7 speakers are prized by horn enthusiasts for their dynamic, uncompressed sound quality. Many have been restored for home use in large listening rooms or for vintage cinema installations.

In the Wild

Featured in Resistor Magazine's restoration profile of Iwan Arjanto's vintage speaker collection. Arjanto, an Indonesian speaker craftsman, discovered his passion for horn-loaded speakers after hearing an Altec horn at a friend's house - an experience he describes as unforgettable.

Arjanto's journey into horn speakers began with acquiring an Altec 511 horn, which led him to learn how to build Altec A7 speakers from scratch. He has crafted four pairs of A7s for customers to date, thoroughly testing each pair before delivery. His approach combines carpentry know-how with extensive internet research through the Lansing Heritage forum and Facebook groups.

"The first time I heard an Altec horn was at my friend's house – he used to play around with full range drivers too – after hearing that horn I couldn't forget its sound. That's when the journey began, I began hunting many horns. The Google became my guru as I would read many old articles about the history involving Western Electric, Altec Lansing, and JBL."

— Iwan Arjanto

Arjanto notes that new JBL cones and networks require extensive break-in - typically 50-100 hours - to achieve their best sound, and he uses digital playback to break in speaker cones during the building process.