Direct path
Distance, axis, directivity, seat blockage, steering wheel, headrest, occupant, and grille transmission.
Speaker Placement, Orientation, And Acoustic Path
A speaker location is the complete installed source: driver, acoustic center, axis, baffle, grille, trim, direct path, reflected paths, obstructions, structure, water exposure, and relationship to each listener.
Evaluate Four Path Families
Early reflections
Windshield, side glass, dash, console, trim, roof, seat, and nearby hard boundaries that alter level, spectrum, phase, and apparent direction.
Leak and back path
Front-to-rear cancellation, door openings, trim gaps, pod leakage, baffle flex, and cavity radiation.
Mechanical and safety path
Adapter stiffness, fasteners, airbags, impact structures, glass, latches, drains, wiring, service access, and crash loading.
Aiming Is A Listening-Window Decision
| Strategy | Possible advantage | Risk to prove |
|---|---|---|
| on-axis to one seat | maximum high-frequency output and one-seat consistency | near/far imbalance and narrow head window |
| cross-fired or off-axis | more similar response across front seats | driver-specific off-axis irregularity or reduced headroom |
| reflected path | packaging or useful apparent elevation | path variability, comb filtering, glass angle, trim, and seat dependence |
| wideband or coaxial shared origin | fewer separated acoustic centers | directivity, breakup, excursion, grille, and bandwidth limits |
There is no universal instruction to point every tweeter at the listener, cross-fire every pillar, or use the windshield as a mirror. Measure the exact driver and location through the final trim for the intended head region.
Prototype Before Permanent Fabrication
- Record three-dimensional driver, baffle, grille, and ear coordinates.
- Measure the driver in candidate angles and positions at low level.
- Install a temporary rigid baffle or pod with the intended seal and grille path.
- Measure magnitude, phase, impulse, distortion, directivity, and nearby-seat response.
- Move one location or angle at a time and repeat with identical references.
- Verify glass, regulator, trim, visibility, restraint, water, heat, and service clearance.
- Repeat after final fabrication and trim installation.
Placement Records
- driver model, sample, polarity, acoustic-center assumption, and axis definition
- vehicle coordinate system and ear positions
- direct and reflected path lengths and obstruction states
- baffle, adapter, gasket, grille, trim, and cavity condition
- candidate and final response families by angle and seat
- fabrication, material, fastener, environmental, and service notes
Final trim is part of the acoustic system.
A location that measures well with a door card, grille, headrest, or dash panel removed has not passed. Repeat the response, clearance, rattle, water, and vehicle-function checks in the final assembled state.