Speaker Aim & Splay Calibration Cookbook

Reference: CAL-COOKBOOK-01. Pairs with the existing "Smaart Setup & Alignment Guide" — that's the measurement-system setup; this is a set of specific, repeatable procedures for the actual aim/splay questions that come up on-site: where to point a single box, how to aim a pair of mains, and how to find the splay angle that gives an even, unity-gain overlap between two array elements.

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Not saved anywhere — resets when you leave this page. Every procedure here assumes you're running a measurement mic and analyzer (Smaart or equivalent) — this is the site-work checklist, not a substitute for actually reading the traces.

Procedure 1 — Aim a Solo Speaker (Horizontal)

Place the measurement mic on-axis (ONAX) — dead-center of the box's intended coverage, at the target listening distance. Take a reference trace at ONAX. This is what you're comparing every other position back to. Move the mic to the horizontal edges of the intended coverage (OFFAX left and right) and compare each trace to the ONAX reference. Pass: OFFAX response tracks the ONAX reference within a consistent, acceptable level/frequency-response difference across the intended coverage width. Fail: one edge shows a much larger deviation than the other — re-aim horizontally toward the weaker side and re-measure.

Procedure 2 — Aim a Solo Speaker (Vertical)

Measure at the top (VTOP) and bottom (VBOT) of the intended vertical coverage — front row to back row, or top to bottom of a balcony throw. Pass: VTOP and VBOT are both usably close to the ONAX reference, accounting for the expected distance-based level falloff between them. Fail: one end is dramatically worse than distance alone explains — adjust vertical aim/tilt and re-measure.

Procedure 3 — Aim L/R Mains

Repeat Procedures 1 and 2 independently for the left and right hangs, on their respective sides of the room. Take a center-line measurement (XAB — equidistant from both L and R) to check the two hangs are matched to each other, not just individually well-aimed. Pass: L and R traces at XAB are closely matched in level and response. Fail: a consistent level or frequency-response offset between L and R at center — check for a processing/gain mismatch before re-aiming either box, since that's a more common cause than physical aim at this stage.

Procedure 4 — Find Unity Splay Angle (Symmetric Array)

With two adjacent array elements both live, find the point in their overlap zone and measure there. Compare the combined (both elements) trace at the overlap point against each element's individual trace at that same point. Unity splay is the angle where the overlap sums to roughly the same level as either element alone — not 6dB louder (too much overlap, elements too close together in angle) and not showing a null (too little overlap, gap between elements). Fail: if the overlap reads hot, increase splay between the elements; if it shows a null or dip, decrease splay. Re-measure after every adjustment.

Procedure 5 — Find Unity Splay Angle (Asymmetric Array)

When the two elements cover unequal throw distances (common at the top of a hang where elements aim at progressively closer audience), the unity point isn't the geometric center of the overlap — it shifts toward the shorter-throw element. Measure at the actual overlap point given the real (unequal) throw distances involved, not at the angular midpoint between the two elements. Same pass/fail logic as Procedure 4: adjust splay until the overlap sums to roughly unity rather than showing a hot spot or a null, re-measuring at the correct (asymmetric) overlap position each time.

Source: McCarthy, Bob. Sound Systems: Design and Optimization, 3rd ed., §14.7 "Calibration Procedure Cookbook," Procedures 14.1–14.6. Rewritten in Ryan's own words from the source material.