Manufacturers Info

Brand: JBL/Selenium

Model: HC23-25

Style: Exponential

Coverage (H x V): 100 x 40

Minimum Frequency: 600Hz

Throat: 1"

Mounting Type: 1-3/8"-18 TPI

Dimensions: 10" W x 5" H x 5.7" D

Additional Notes:

Thanks to jvphotog for sending me this horn to test.

Diffraction style horn which uses a slotted grill in the middle of the throat to widen coverage.

Measurements:

Test Notes: Off axis and polars measured using a Celestion CDX1-1731 compression driver.

Mic distance 1m, measurements gated at 4.5ms and are smoothed at 1/48 Octave.

Horizontal:

Vertical:

Raw horizontal off axis response

Raw vertical off axis response

Horizontal off axis response - normalized to on axis

Vertical response - normalized to on axis

Horizontal Polar Response - Normalized to On Axis

-6dB Coverage Angle Highlighted

Vertical Polar Response - Normalized to On Axis

-6dB Coverage Angle Highlighted

Notes:

The diffraction grill design introduces a bunch of reflections in the throat which makes a real mess of the frequency response. The average coverage might be roughly 100 x 40 but it varies wildly with frequency. Not a great horn unless you need wide horizontal coverage with decent low frequency loading and don't mind the overall hash in the frequency response. The JBL 338800-001 or clones (like the Dayton H6512) might be a better choice as my testing shows that style horn does have roughly 100 degree horizontal coverage and is a much better design overall.