288 compression driver

Why it mattered

1. 01

   It was the high-frequency partner of the 515Altec Lansing515 low-frequency driver1945; 515B 1966The Altec 515 is a 15-inch woofer with a 3-inch edge-wound voice coil and Alnico V magnet, designed for large bass horns in the Voice of the Theatre systems. The 515B was catalogued from 20 Hz to 1,000 Hz.Open profile → woofer in the A4Altec LansingVoice of the Theatre A41945The A4 Voice of the Theatre, co-designed by James B. Lansing and John Hilliard and introduced in 1945, paired a horn-loaded bass cabinet with two 15-inch [[altec-515|515]] woofers and a multicellular horn driven by the [[altec-288|288]] compression driver.Open profile → and A7Altec LansingVoice of the Theatre A71950sThe A7 was Altec Lansing's compact Voice of the Theatre: a folded bass horn with a [[altec-515|515]] 15-inch woofer and a multicellular horn driven by an [[altec-288|288]] compression driver. It scaled the original Voice of the Theatre cabinets down for smaller rooms, and its high sensitivity suited the low-power valve amplifiers of the time.Open profile →.

   Altec Lansing 515 low-frequency driverJacques from Cape Town, South Africa · CC BY 2.0Altec Lansing Voice of the Theatre A4© FOH magazine; photographer not credited · Rights retained by the rights holder; reproduced for historical commentaryAltec Lansing Voice of the Theatre A7© FOH magazine; photographer not credited · Rights retained by the rights holder; reproduced for historical commentary

2. 02

   Continual revision made it one of the most widely used compression drivers in American cinema and PA for decades.

Engineering record

Diaphragm

Aluminium diaphragm, interchangeable with later 291-series diaphragms[1]

Motor evolution

Alnico with circumferential phase plugs early; ceramic magnets with Tangerine phase plugs later[1]

Impedance variants

8, 16, 24 and 32-ohm versions across revisions[2]