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— Speaker Coverage · Point source

JBL Professional Control 25-1: SPL & coverage

Problem. A 20 x 12 m restaurant relying on background music needs a cabinet that stays intelligible at a 6 m listening distance without overpowering nearby tables. The real decision is whether the Control 25-1's rated output and dispersion give adequate SPL at that distance once drive level is set for comfortable background listening rather than full output.

Answer. At the planner's default restaurant-bgm scene, a Control 25-1 driven at 50 percent delivers approximately 97 dB SPL to a listener 6 m away. Its 100 degree by 100 degree dispersion also yields a horizontal coverage half-width of approximately 7.2 m at the -6 dB threshold, before overlap or room treatment is considered.

02 / In depth

How this preset reads — the engineering view.

The Control 25-1 is rated at 116 dB maximum SPL at 1 m. Because sound pressure falls off with the inverse square of distance, that figure drops to roughly 100 dB at 6 m when the cabinet is driven at full output, and to roughly 97 dB at 6 m when drive is reduced to 50 percent for a background-music level.

The cabinet's 100 degree by 100 degree nominal dispersion (H x V) sets a horizontal -6 dB coverage half-width of approximately 7.2 m in this scene. The wide, even pattern favours near-field fill over long throw, which suits a room where listeners sit close to the cabinet rather than across a long hall. Being a passive design, the Control 25-1 needs a matched amplifier channel sized to its rating rather than built-in powered electronics.

Use the planner by dragging the listener-distance and drive-level controls to watch the SPL readout move in real time. The box-count suggestion is a front-coverage estimate based on dispersion angle and room geometry; SPL adequacy at the listener position is a separate check the planner runs alongside it, and both should be read together before settling on a layout.

The planner does not model room reverberation or RT60, so a hard-surfaced dining room will sound louder and less clear than the SPL number alone suggests. It also does not handle zoning across separate areas, subwoofer pairing for low-frequency reinforcement, mechanical rigging for arrays, or DSP and delay-line tuning between multiple cabinets — all of these remain judgement calls for the room design stage.

What this preset deliberately does not solve

  • SPL figures are calculated from the rated 1 m maximum and simple inverse-square distance loss; they do not account for room reflections, absorption, or furnishing density.
  • Coverage half-width is a geometric estimate from the nominal dispersion angle and assumes a single cabinet with no overlap planning against neighbouring units.
  • The planner does not verify amplifier pairing, cable loss, or impedance matching required for the Control 25-1's passive format.

How this preset differs from its siblings

Other point-source options in the catalogue carry different maximum SPL ratings and narrower or asymmetric dispersion patterns, which shift both the coverage half-width and the achievable listener-position SPL for the same room. A cabinet with a tighter dispersion angle would concentrate energy over a smaller area at greater distance, while a lower-rated cabinet would need a shorter listener distance or higher drive to reach the same 97 dB target. This preset exists so a visitor comparing the Control 25-1 specifically can see its own numbers rather than a generic point-source estimate.

02 / What that means, drawn

Plan view, drawn to one scale in both directions. The room is 20.00 m deep by 12.00 m wide, with the cabinet on the front wall and the listener 6.00 m down the axis. JBL Professional Control 25-1 has a nominal horizontal pattern of 100°, so the covered shape is a wedge whose apex is at the CABINET, not a circle around the listener. The wedge is drawn at half that angle either side of the axis. At the listener's distance that wedge is 14.30 m across — 7.15 m either side of the axis. That width is the published figure, and it is the only coverage quantity this tool establishes. The room is 12.00 m wide there, so one cabinet covers the full width with 2.30 m to spare across the two edges combined. The wedge is the nominal beamwidth drawn with straight edges. It is not a measured -6 dB contour, and it is a HORIZONTAL quantity only: no vertical coverage, and no covered area, is claimed here. This cabinet's vertical pattern is 100°, and the difference between the two is exactly why a single circular figure would misstate the covered patch.

This preset’s geometry, drawn to one scale in both directions from the same derivation the calculator below uses. The wedge is JBL Professional Control 25-1’s nominal 100° horizontal pattern, not a measured contour, and no vertical coverage or covered area is claimed. Move the controls below to change it.

03 / Hydrated calculator

Try the configuration — live.

The calculator below is preloaded with this preset’s state. Adjust any input — your URL stays shareable.

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Brief us on the project — with this configuration.

Presets are a typology starting point. The brief wizard captures the room geometry, programme and constraints we need to translate this configuration into a real design.