JBL 4520

Commentary

Floor type enclosure using rear loading horn system.

The inside has a folded horn structure with a total length of 4m, enabling playback in the low frequency range up to 30 Hz and showing a flat response over 50 Hz.
Frequencies higher than 150 Hz are emitted directly from the speakers, making it possible to play extremely voluminous bass sound.

The unit can mount two 38 cm diameter speakers.

Initially, there are 2 color variations of black and gray, 4520 sf is finished in gray and 4520 bk is finished in black.
In addition, in the catalog photo, there is no logo on the side in the early stage, and there is JBL logo on the side from around 1978.

The 4520BK-S is a Japanese domestic type. By this time, imported original products were ordered to order.

Model Rating

Method	Backload horn type floor enclosure
Compatible Speaker	2205, 2225, E140
Minimum regeneration frequency	30Hz
External dimensions	Width 908x Height 1,276x Depth 736 mm (1973 catalog) Width 908x Height 1,276x Depth 756 mm (listed in the catalog after 1975)
Weight	108 kg (according to 1973 catalog) 98 kg (listed in the catalog after 1975)