The 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 ohm system uses two 2226H 380 mm (15") 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.
The enclosure is constructed of dense stock and is extensively braced on all panels. Net internal volume is 225 L (8 cubic feet), and the enclosure is tuned to 40 Hz. Port area is large, ensuring minimum turbulence at full power input at low frequencies.
Key JBL 4648A Features: