ResonantLive Sound Archive

Equipment file · Front-loaded horn bass enclosure (JBL 4560)

JBL 4560 cabinet

JBL · 1971

Evidence status · documented

Identity and core specifications are documented; some historical fields remain unavailable.

JBL's answer to the theatre-horn era in PA was the 4560, a front-loaded horn bass enclosure for one 15-inch driver such as the 2205 or 2220, used below 800 Hz and reaching about 60 Hz. It appears throughout JBL's theatre and PA system charts.

Introduced
1971
Category
Front-loaded horn bass enclosure (JBL 4560)
Intended use
Low-frequency reinforcement for theatre and touring systems
Production
JBL, 1971 through the 1980s (4560, 4560A, 4560BKA)

Why it mattered

  1. 01

    It let sound companies build scalable bass systems around standard 15-inch drivers.

  2. 02

    It was a building block of JBL's 1970s theatre and PA systems, alongside the twin-driver 4550.

Engineering record

Loading
Front-loaded horn with reflex chamber, usable to about 60 Hz[1]
Size
752 × 914 × 610 mm, about 41–46 kg[1]

Original pricing

No reliable period price located

2026 equivalent

Not calculated without a reliable original price.

Public price evidence was not sufficient to publish a defensible original figure.

Use in the field

No named deployment could be tied to this exact item by a checked source yet. Know of one? Suggest it on the contribute page.

Manuals & original documents

Sources

  1. 1JBL 4560 Specificationsaudio-database.com · reference
  2. 2Theatre and Public Address Systems Reference ChartJBL · brochure · 1984

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