The JBL 4648A low frequency system is designed for general reinforcement and motion picture theater use where high power output with smooth power response and low distortion are essential. The 4648A system covers the frequency range from 35 Hz to 500 or 800 Hz, depending upon application.
The 4648A 4 O system uses two 2226H 380 mm (15 in) patented Vented Gap Cooling transducers for high power handling and reduced power compression. The transducers feature 100 mm (4 in) voice coils operating in a large symmetrical field geometry (SFG) magnet structure to reduce a second harmonic distortion to inconsequential levels. The total linear excursion capability of each transducer is 10 mm (0.4 in), peak to peak, and total harmonic distortion (THD) is less than 2.5% from 40 to 800 Hz with sine wave input of 100 watts.
Model 4648A-8 is the 8 O version of this system, incorporating two 2226J transducers, used with models 4675B-2 and 4675B-8LF high frequency systems.