JBL 2370A Flat-Front Bi-Radial Horn

The JBL 2370A is a compact Bi-Radial horn with a nominal coverage pattern of 90 degrees horizontal x 40 degrees vertical. The horn provides uniform on and off axis frequency response in the horizontal plane from 630 Hz to beyond 16 kHz. The horn's small vertical mouth dimension was chosen to allow a gradual narrowing of the vertical coverage pattern with increasing frequency. This provides acoustic equalization of the frequency response of the horn in the horizontal plane and compensates for the falling power response of all compression drivers. Should constant vertical pattern control be required, two or more 2370As may be stacked to restore full Bi-Radial performance.

The horn's exceptionally consistent horizontal dispersion eliminates the midrange narrowing and high frequency beaming problems typically associated with conventional horn designs. Additionally, the 2370A's highly predictable performance greatly simplifies cluster design. The need for horn overlapping is minimized and lobing and comb filter effects are virtually eliminated.

Computer-aided design techniques were used to derive the horn contours in the horizontal and vertical planes. Utilizing sidewall contours based on a polynomial power series formula, the horn design yields smooth response, low distortion and even coverage. This design avoids the performance disadvantages of horns that feature sharp flare transitions and flat sidewalls. The Bi-Radial compound flare configuration of the horn provides constant coverage over defined, solid angles.

The 2370A features an integral throat that will accept any JBL compression driver having a 25 mm (1") throat diameter. The flat front design of the horn allows flush mounting on enclosure baffles. Mounting tabs are provided for enclosure or cluster mounting. To ensure freedom from resonances, light weight and superior strength, the horn belt is constructed of molded structural foam.