JBL 4828

The JBL 4828 is a professional sound reinforcement loudspeaker from JBL Professional, built for full-range duty. It's a straightforward, no-nonsense design: a single 15" VGC (Vented Gap Cooled) woofer paired with a 2408H high-frequency compression driver on a 90° x 50° PTF (Pattern Transfer Function) horn, crossed over passively at 1 kHz. The specs tell a consistent story across the surviving listings: 400 watts program handling (800 watts peak), 97 dB sensitivity, 8 ohms nominal impedance, and a frequency range of 42 Hz to 18 kHz. Maximum output is rated at 123 dB continuous, 129 dB peak. It measures 16.5" x 25.5" x 16.5" and weighs 51 lbs.

Surviving documentation on the 4828 is thin. No production years, original pricing, or period marketing materials have surfaced, and the model doesn't appear in the era's major hi-fi press — it was aimed at the commercial installation and touring market rather than home audio, which explains the sparse paper trail. Coverage of professional sound reinforcement in the era's trade press focused on trends in stage monitoring for concert sound, a category that included speakers like the 4828 (Mix, June 1988, p.159). What's recorded comes almost entirely from dealer listings and pro-audio catalogs, all of which agree on the core specifications above. One potential wrinkle: a UK dealer lists the same speaker as the "JBL 4828-II," with identical specs, which may indicate a later revision or simply a cataloging quirk — the record doesn't clarify which.

What's known, in brief:

Type: Full-range sound reinforcement loudspeaker
Drivers: 1 x 15" VGC woofer; 1 x 2408H high-frequency driver
Horn: 90° x 50° PTF waveguide
Crossover: Passive, 1 kHz
Power handling: 400 W program / 800 W peak
Sensitivity: 97 dB @ 2.83 V/m
Impedance: 8 ohms
Frequency range: 42 Hz – 18 kHz
Max SPL: 123 dB continuous / 129 dB peak
Dimensions: 16.5" x 25.5" x 16.5" (418 x 648 x 418 mm)
Weight: 51 lbs (23 kg)

Beyond these figures, almost nothing else is documented. No user reviews, no known failure points, no service history. It's a working professional tool from JBL's pro line, and the available record treats it that way — functional specs, no romance. If you have one, the numbers suggest it's a capable, efficient box; if you're hunting for one, the 4828 remains an obscure entry in JBL's extensive catalog.