→ SketchUp Builder v4 (config-driven)
01 Room
Applies to every dimension in this questionnaire — room, seating, speaker positions, and the exported SketchUp config file.
Distance from the screen position to the back wall.
Applies the chosen ratio to width and length, using the room height above as the "1" — e.g. Bolt centre at a 2400mm ceiling gives 3360mm width and 4560mm length. These are well-studied room-mode ratios that spread axial modes evenly rather than clumping them; the same reference set appears again in the detailed acoustics report once the room is set up. Picking a preset overwrites the width/length fields above — set back to "Keep my dimensions" to edit them freely again.
Distance from the screen wall to the true front (structural) wall — the hidden chamber depth behind an acoustically-transparent screen. Set to 0 if there's no baffle wall.
A lowered perimeter ceiling border running around all four walls, dropped down from the main ceiling — commonly used to conceal wiring, HVAC, or acoustic treatment. The centre of the room stays at full ceiling height.
Real rooms have chimney breasts, stair bulkheads and splayed screen walls. Choosing a shape here cuts into the length/width set above, and floor area and volume are recalculated from the true outline rather than length × width — this is what feeds the acoustic reading in Acoustics.
Flat: the room height set above applies everywhere. Sloped: full height at the screen wall, down to room height at the back. Vaulted: full height along the centre, down to room height at both end walls.
The shape and ceiling profile set here draw directly into the 2D Top and Side views on the right, and into the 3D model — there's no separate preview to keep in sync.
🔒 Detailed Report — Room
02 Seating
Which seating row the main listening position sits in. "MLP distance from screen" (Screen section) measures to this row specifically — the other rows are then spaced forward/back from it as usual.
Distance between each row's seated ear position, front to back.
Gap between adjacent seat edges within a row, in addition to each seat's own footprint width.
Height of each riser tier (2+ rows only) — row 2 sits one step up, row 3 sits two steps up.
Recessed: a half-height step cut into the riser at each side, starting at the riser's front edge and running 500mm back toward the back wall. Forward: a half-height step ahead of the riser, in the side aisles next to the front row.
A small oval marks each seat's head/ear position (always shown, once this section is opened). Checking this also draws sightlines from every seat to the screen speakers (FL/FR) and shows each seat's own viewing angle — useful for checking sightlines beyond just the MLP, though it can get busy with a full room.
🔒 Detailed RP22 Compliance Report — Seating
03 Visual
Screen gain: 1.0 is a standard matte-white screen (light spread evenly in all directions); below 1.0 is typical of ambient-light-rejecting (ALR) screens, which trade some on-axis brightness for better contrast under room light; above 1.0 concentrates more light back toward the seating area at the cost of a narrower, more direction-dependent viewing cone. This will eventually be set automatically from a screen model picker — for now, enter it directly from the screen's datasheet. Feeds into the light output report in the paid section below.
Acoustically transparent: shown 25% see-through in the 3D view so the L/C/R speakers mounted behind it are visible — matches a real AT screen's woven/perforated material, which passes sound (and lets you glimpse the speakers) while still showing an image. The 40mm black edge frame is always shown, opaque, regardless of screen type.
Reference brightness targets in use today, from Commercial Digital Cinema (the SMPTE ST 431-1 mastering-referred figure) through to HDR Projection, which benefits from extra headroom. Pick whichever is closest to your own use case — it decides which target your calculated output below is checked against.
Applies to screen width and diagonal only — independent of the room's units.
Blank width = auto-sized to room width × 0.75. Refer to CTA/CEDIA-CEB23-B for formal screen sizing. Width and diagonal stay in sync — edit either one. Lock freezes the width even if room width changes.
Applies to MLP distance only — independent of the room's units.
🔒 Paid Feature — MLP Distance & Recommended Screen Sizing
Distance from the screen plane to the main listening position (ear level of front-row centre seat). While the Lock switch above is off, you can also drag the gold star (MLP) forwards/backwards directly on the top-view diagram below — every speaker angle recalculates live as you move it. Dragging works whether or not the detailed report at the top of the page is unlocked; unlocking that just reveals the exact distance figure here.
Computed from your current MLP distance above and this target angle — screen width = 2 × distance × tan(angle ÷ 2).
Reference 0°–15° per SMPTE RP22, centred on 5° (green) — the angle from the MLP's seated ear height up to screen centre, which sets the screen's height on the wall. With 2+ rows, the screen is raised above this target only if needed so the bottom edge stays visible over the row(s) in front.
Representative current models (mid-2026) — always confirm exact throw-ratio and lens-shift figures against the manufacturer's datasheet before final placement.
Draws the same translucent throw-angle spread shown in the 3D view (toggle "Projector throw" there) — from the projector to the screen's edges — over the top/side diagrams here.
🔒 Detailed RP22 §5.5 Compliance Report — Screen & Viewing
04 Audio
4.1 Speaker Layout
Base.Subs.Heights — base channel count sets side/rear surrounds (and front wides at 9+), heights sets the overhead layer. Angles below follow RP22 §5.5–5.8 methodology: screen → surround → wide → upper.
Speaker to wall: L/C/R cabinets face straight out from the front wall (RP22's default) — the dashed line to the MLP shown once this section is revealed is just the angle reference, not the speaker's own facing. Direct to MLP: cabinets toe in so that line runs square into the front baffle instead. Only available where the L/C/R mount type (Advanced section) is On-wall — an in-wall baffle is fixed flush with the wall and can't be angled.
Same as L/C/R facing above, but for the surround family — side/rear surrounds and front wides. Only available where the Surround mount type (Advanced section) is On-wall; set independently from L/C/R facing.
Reference 22°–30°, centred on 26° (green) — RP22 §5.5.1. Amber to ±15° beyond (10°–45° total range). Moves FL/FR along the screen wall independently of the visible screen edges (e.g. for speakers mounted behind an acoustically-transparent screen at a different width).
Reference 90°–110°, centred on 100° (green). Amber to ±15° beyond (75°–125° total range).
Reference 135°–155°, centred on 145° (green). Amber to ±15° beyond (120°–170° total range). Solved from true room geometry — if a shallow room can't physically reach the target, the closest achievable angle is shown and flagged "(limit)".
In-ceiling mounts true overhead speakers. Upward-firing mounts modules on top of the base-layer cabinets (front and/or surround) and computes the ceiling bounce point using the mirror-image method.
In-ceiling: recessed, flush round baffle — the usual choice, shown as a flat disc. On-ceiling: surface-mounted box speaker fixed to the ceiling instead, shown at its real footprint like a surround cabinet, angled so its front face always points straight at the MLP.
Reference 35°–55°, centred on 45° (green). Amber to ±15° beyond (20°–70° total range). Offsets the front overhead pair forward of the MLP.
Moves the front overhead pair outward (+) toward the side walls, or inward (−) toward the centreline, independently of the rear pair — clamped to stay within the room.
Reference 80°–100°, centred on 90° (overhead, green). Amber to ±25° beyond (65°–115° total range). Below 90° tilts the pair toward the front; above 90° tilts it toward the rear, by the same amount.
Reference 35°–55°, centred on 45° (green). Amber to ±15° beyond (20°–70° total range). Offsets the rear overhead pair aft of the MLP.
Moves the rear overhead pair outward (+) toward the side walls, or inward (−) toward the centreline, independently of the front pair — clamped to stay within the room.
🔒 Paid Feature — Subwoofer Placement
Only affects layouts with exactly 2 subwoofers — other counts keep their existing pattern. Both start near the back wall; the adjustments below move them outward/inward and up/down from there.
Moves each sub outward (+) or inward (−) from its starting width position, up to 1000mm each way, clamped to stay inside the room.
Up to 75% of room height.
🔒 Detailed RP22 Compliance Report — Speaker Layout
4.2 Low Frequency — Trinnov WaveFormingoptional
Floor: 600×600×600mm (W×H×D), free-standing. Wall: 600×1200×290mm, mounted to the front wall the same way as the L/C/R speakers — behind the baffle wall when one is set.
Floor: 600×600×600mm (W×H×D), free-standing. Wall: 600×1200×290mm, mounted flush to the rear wall.
Width position is % of room width from each side (25% = the standard ¼/¾ points). Height is % of wall height from the floor (50% = centre). Not shown for the corner-loaded layout, which is fixed at the wall/floor or wall/ceiling corners.
Trinnov WaveForming guidelines: requires a minimum of 4 subwoofers, arrayed on the front and rear walls (2 front + 2 rear at minimum). Regular arrays perform best, positioned flush to the wall at the ¼ and ¾ points of the wall's width. Asymmetric arrays are supported — front subwoofers matter more than rear, so a fewer-rear layout (e.g. 4-2) outperforms an even split (3-3) for the same total count. Up to ~10% positional displacement from the ideal is tolerated for real-world obstructions (screens, doors, equipment). Measurement microphones should sample at least 2m from the front array and 1m from all other boundaries.
🔒 Detailed Report — Low Frequency / Subwoofers
4.3 SPL Calculator
Estimates the sound pressure level every speaker actually achieves at every seat, using each speaker's real measured distance from that seat (already known from the room layout above) rather than one assumed listening distance. Based on the standard SPL = sensitivity + 10·log₁₀(power) − 20·log₁₀(distance) + placement gain relationship — an on-axis, free-field estimate; real rooms, reflections and off-axis seating shift results by a few dB either way, so treat this as a sizing check rather than a guarantee.
Applied uniformly to every speaker — reflected "room gain" from nearby boundaries, strongest at bass frequencies.
Real-world multichannel power is lower than the 2-channel-driven spec most amplifiers are rated at.
Colours both 2D diagrams below by how well each point sits inside the selected speaker's real dispersion — green at the centre of the beam, red outside it. In the top view, sampled at that speaker's own height for a level-firing speaker (L/C/R, surround), or at seated ear height for a down/up-firing one (height/Atmos), where the coverage question actually resolves to something a listener experiences. The side view doesn't need that substitution — height is already one of its two axes — so it's sampled at each speaker's own real position throughout, centred naturally on its true mount height. Step through to a specific channel, or "All" for the best result from any of them at each point in the room.
🔒 Detailed Report — Per-Seat SPL
05 AcousticsRP22 §9
5.1 Reflection Points
Early reflections reach the ear only a few milliseconds after the direct sound, and where they bounce from decides whether they widen the image or smear it. This is usually the first thing worth getting right — it's a fixed, one-time geometry decision, unlike room modes below which shift with every seat and sub position.
RP22 §9.2.2 recommends diffusion at the side-wall mirror points for stereo or up to 7 listener-level speakers — reflected energy there adds spaciousness rather than smearing, per Toole's precedence-effect research. Absorption is still used automatically where front wide speakers sit at the mirror point, or for systems above 7 listener-level speakers, regardless of this choice. Hybrid absorber/diffuser panels (e.g. GIK's Alpha/Amplitude series) combine both in one unit — a good middle ground where you want the imaging benefit of absorption without fully losing spaciousness. Any spot where absorption and diffusion would otherwise land in the same place is also automatically upgraded to hybrid.
For each front speaker, marks where its sound would first bounce off a side wall or the rear wall before reaching every seated head (image-source / mirror method) — beyond the standard RP22 side-wall mirror zones above, useful for spotting extra spots that may need treatment, especially for seats behind the MLP. Shown in both 2D views and the 3D view. Toggle each speaker independently — showing all three across every wall and every seat at once gets busy fast.
5.2 Room Modes
A room's dimensions decide which bass notes reinforce and which cancel, long before any subwoofer is chosen. This chart gives a visual sense of your room's own modal behaviour, computed from the dimensions set in Section 01 — the full frequency breakdown, gap warnings and ratio analysis are in the detailed report below.
Sets the room's own reverberation time (not a fixed constant), which decides the transition (Schroeder) frequency — the point where discrete, individually-audible modes give way to a smooth statistical reverberant field. A shorter target (a more damped room) pushes that frequency down, meaning geometry-driven mode problems matter over a narrower band and ordinary treatment takes over sooner.
Axial modes travel between one opposing pair of surfaces and are by far the strongest — start there, then add tangential/oblique modes for the fuller (and busier) picture.
Modal distribution to 250 Hz
Length
Width
Height
Tangential / oblique
5.3 Treatment Level
Automatic sizes and positions every panel from the room's own reflection-point and layout geometry, per RP22. Manual override instead lets you pick a total panel count within the current level's coverage band above, split across the two side walls and the rear wall in proportion to each wall's own area — useful when a fixed budget or supplier pack size drives the count instead of the geometry.
Triangular corner bass traps at the front wall corners (and, from Level 2, the rear corners too) — corner-loaded low-frequency buildup is otherwise very hard to address any other way, so this is on by default, but untick it if the corners are already committed to something else (a riser, equipment, built-in cabinetry) or bass trapping is being handled separately from this plan.
🔒 Paid Feature — Manual Panel Positioning
Drag any mirror-point or diffusion-band panel directly on the side-view diagram below to nudge it sideways (depth) or up/down (height) — the opposite wall's matching panel moves with it, and the top view updates automatically. Click a panel (without dragging it) to cycle its own treatment type through absorption → diffusion → hybrid, independently of the others. Panels within 100mm of another panel's edge — or the room's own floor, ceiling, back wall or screen wall — snap flush against it, and the other axis snaps to match too so corners line up square rather than at a slight offset. Bass traps, keep-clear markers, rear-wall and ceiling panels are fixed and can't be dragged or recoloured this way. A manual nudge is kept until something that would move that panel anyway (room size, speaker height, seat layout, treatment level) changes, at which point it recalculates fresh; a manual type choice is kept until reset.
Absorption
Diffusion / scattering
Hybrid (both)
Bass trap (corner)
Ceiling keep-clear (reflection point)
🔒 Detailed RP22 §9 Compliance Report — Acoustic Treatment
06 Star Ceiling
Standard: an even fibre field on panels centred over the room. Switch to Custom to shape the pattern, density, colour and panel position.
Defaults to the room's own ceiling dimensions — the bulkhead's inner (flat) area if one is enabled in the Room section, otherwise the full room width and length. Override either field if the star field should cover a smaller area still.
A cove-light effect around the panelled area, as pictured by the client reference — either inset from the star ceiling's own edge, or run out from the star ceiling to the surrounding wall/bulkhead.
Panel grid laid over the room. Offset shifts the run where a beam or light fitting gets in the way.
Standard engines drive up to 400 fibres each, centrally distributed. Starz Custom Light Engines carry up to 112 fibres each and are generally fitted one per panel — Custom adds a per-panel engine count and total to the installer summary below.
🔒 Detailed Star Ceiling Drilling Schedule
07 Advanced — fine-tune placement defaults
🔒 Paid Feature — Advanced Placement Defaults
General clearance kept between speakers/equipment and the walls, used throughout as the default wall-facing reference. Defaults to 0 (speakers referenced flush to the wall) — increase this if speaker mounts, brackets, or in-wall boxes need standoff room to actually be installed.
Height of the rear/surround-back speakers (SBL/SBR) specifically. Side surrounds and front wides — if present in the selected speaker configuration — get their own adjustment below instead of sharing this value.
Moves the side surrounds (SL/SR) up (+) or down (−) from the rear surround height above, up to 300mm each way — they sit between the LCR and rear surrounds, so often want a height partway between the two.
On-wall: back of the cabinet against the front wall, extending into the room — the usual choice with no baffle wall. In-wall: recessed, front baffle flush with the wall surface — the usual choice for speakers mounted on a baffle wall behind an acoustically-transparent screen. Independent of the baffle wall setting above; set to match your actual mounting.
On-wall: bracket/stand-mounted, back of the cabinet against the wall, extending out into the room. In-wall: recessed into the wall cavity, front baffle flush with the wall surface. Applies to every surround-family speaker box (side/rear surrounds and front wides) — set independently from the L/C/R mount type beside it.
Physical cabinet size shown for every speaker box in the 2D and 3D views (surrounds, front wides, and rear surrounds use the surround size; L/C/R and front-centre use the L/C/R size). Purely visual/spatial — doesn't affect any acoustic calculation.
Shown as a flat round disc — a real in-ceiling speaker's shape — for every overhead/Atmos marker in the 2D and 3D views, in place of the previous point locator. Purely visual — doesn't affect any acoustic calculation.
08 Summary
🔒 Paid Feature — Summary & Export
Tell us about your experience using the designer, or suggest something we should add or change — this isn't part of the paid report, so it's open whether or not you've unlocked anything above.
2D Drawings — Top & Side View
Top view
Side view