JBL Professional SRX906LA — SPL & coverage, conference hall

The SRX906LA is rated 134 dB SPL at 1 m. SPL falls with distance under the inverse-square law: at 15 m and full output the planner returns roughly 110 dB, and at the preset's 60% drive setting that eases to roughly 108 dB at the listener — well above the intelligibility floor for a conference room this size, with margin left in the cabinet.

The 120° x 15° (H x V) dispersion is what sets the roughly 26 m horizontal coverage half-width on the -6 dB axis for this room. The wide horizontal spread suits a broad seating plan, while the tight 15° vertical pattern keeps the wavefront off the ceiling and floor, controlling throw and reducing the reflections that erode speech clarity. The cabinet is self-powered, so the planner's drive-level input maps directly to the box's own amplification rather than an external amplifier channel.

To use the planner: drag the listener distance and drive-level sliders and watch the SPL figure move in response. Box count is a separate estimate: the angle the room's width subtends at a front-centre position, divided by the cabinet's horizontal dispersion — it brackets how many cabinets span the width, while the SPL reading is the separate feasibility check confirming the chosen cabinet and drive level actually reach the listener at an adequate level.

The planner does not model room reverberation or RT60, so a hard-finished conference hall will read louder and less intelligible in practice than the raw SPL figure suggests. It also does not handle zoning across separate seating areas, subwoofer pairing for programme material below the cabinet's low-frequency roll-off, array mechanical rigging, or the DSP/delay tuning that a commissioned system would apply.