JBL HM17-25

Manufacturers Info

Brand: JBL/Selenium

Model: HM17-25

Style: Bi-Radial

Coverage (H x V): 60 x 40

Minimum Frequency: 1,500Hz

Throat: 1"

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

Dimensions: 6.34" W x 5.16" H x 4.16" D

Subjective notes on build quality:

Decent looking waveguide if you don't mind the protruding lobes of the bi-radial design. Overall fit and finish is excellent for it's low cost. Plastic is fairly thin but is not cheap feeling, it's a softer plastic which makes it well damped as it does not ring or resonate if knocked upon.

Measurements:

Test Notes: Off axis and polars measured using a Blast King 72BHM200PL compression driver. Off axis measurements are smoothed to 1/24 Octave.

Horizontal:

Vertical:

Horizontal response normalized to on axis

Vertical response normalized to on axis

Notes:

Both the horizontal and vertical coverage is well controlled down to just about 2khz or maybe a little above. Both axis exhibit some narrowing of the pattern as frequencies rise but the coverage is otherwise very smooth with no major deviations in the overall shape on either axis. Actual coverage pattern as tested does appear closer to a nominal 80 degrees horizontal and 60 degrees vertical.

On axis frequency response & distortion from tested compression drivers:

On axis - measured at 1m (scaled to 2.83v), no smoothing, 4ms gate:

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Distortion, measured at ~100dB/1m:

Distortion normalized to fundamental, measured at ~100dB/1m: