Restoring a KEF Cadenza
KEF Cadenza
The KEF Cadenza (model SP1024) is a classic vintage loudspeaker manufactured by KEF Electronics in Maidstone, England, primarily between 1970 and 1974. It is widely regarded as a high-quality "British Sound" monitor known for its exceptionally detailed midrange and smooth bass extension.
Key Technical Specifications
The Cadenza is a two-way system that uses a passive radiator to enhance low-frequency performance, giving it the appearance of a three-way speaker.
Drive Units:
Tweeter: 1 x T27 (SP1032) dome tweeter, famous for its use in the BBC LS3/5a.
Woofer: 1 x B200 (SP1022) 8-inch mid/bass unit.
Passive Radiator: 1 x BD139 (Acoustically Coupled Bass Radiator) which provides the "beefy" low end.
Impedance: 8 Ohms.
Frequency Response: 30 Hz to 30,000 Hz (though some sources cite 40 Hz to 30 kHz).
Power Handling: Rated for 30W programme; recommended for amplifiers between 15W and 30W (though users often find 40W+ provides better control).
Enclosure: 45-liter cabinet, typically finished in walnut, teak, or white wood veneer with cloth grilles.
Weight: Approximately 15–16 kg (33–35 lbs) per speaker.
Performance & Modern Usage
Sound Profile: Owners describe the Cadenza as having a "very clear and detailed midrange" that excels at jazz, classical music, and female vocals. While not as surgically accurate as modern KEFs, they offer a rich, "alive" sound that fills rooms easily.
Maintenance: Due to their age, many units benefit significantly from a crossover recap. Replacing the 50-year-old electrolytic capacitors (often original ELCAP types) can resolve "smeary" or distant sound and restore the speaker's original clarity.
