Getting the Best Sound From Bi-Radial Horn Loudspeakers
Bi-radial horn loudspeakers can produce exceptional clarity, dynamic scale, and directivity control, but their placement deserves more care than simply positioning two cabinets on either side of a sofa. The horn’s horizontal and vertical dispersion patterns shape how energy reaches the listener, the side walls, ceiling, and floor.
A successful setup balances direct sound with carefully managed reflections. The goal is a stable stereo image, natural tonal balance, convincing depth, and enough room interaction to keep the presentation spacious without making it diffuse. Small changes in toe-in, height, or distance from a boundary can be clearly audible.
Sunship Audio systems combine compression drivers, woofers, wooden bi-radial horns, time-aligned crossovers, and rigid birch plywood cabinets. Those design choices make accurate positioning especially rewarding because the system can reveal subtle differences in geometry and acoustic timing.
Start With Acoustic Geometry
Begin by treating each loudspeaker as a controlled acoustic source rather than a conventional box that simply fires forward. A bi-radial horn spreads sound across a defined horizontal angle while limiting unnecessary energy outside that pattern. This helps preserve clarity, though the room still influences bass, lower midrange, and reflected treble.
Place the speakers on the same wall and keep their front edges aligned initially. Avoid setting one cabinet closer to a side wall than the other, since unequal reflections can pull the image toward one side and alter perceived brightness. Measure from the front wall and side walls so both speakers begin with matching distances.
A useful starting point is to position the cabinets between 70 and 120 centimetres from the front wall, depending on room size and bass response. Larger rooms may benefit from more space behind the speakers, while smaller rooms often require a closer boundary position to avoid excessive image thinning.
Build A Symmetrical Listening Triangle
Create an approximately equilateral triangle between the two loudspeakers and the primary listening position. The distance between the cabinets should initially be close to the distance from each cabinet to the listener. This arrangement gives the stereo image a coherent centre while allowing the horns to combine naturally.
Toe-in is the next major adjustment. Aim each horn toward the listening position as a starting point, then test a slightly wider angle by turning the cabinets outward in small increments. Direct alignment often produces a focused centre image and strong presence; reduced toe-in can increase spaciousness and soften upper-frequency energy.
The ideal angle depends on horn dimensions, room absorption, and listening distance. If vocals appear too intense or the soundstage seems narrow, reduce toe-in. If the centre image is vague or treble lacks definition, increase it. Make identical changes to both speakers and listen from the central seat.
Set Height And Vertical Aim
The acoustic axis of the compression driver should generally point toward the listener’s ear level. With many horn-loaded systems, this means the horn throat or central wavefront sits somewhat above the woofer, so cabinet height and listening distance affect the perceived tonal balance. A loudspeaker that is too low can make the presentation feel compressed and overly floor-bound.
Use stable stands or the manufacturer’s intended base rather than improvised supports. The cabinet should remain rigid and level, with no rocking or forward tilt unless the design specifically calls for it. Mechanical stability protects imaging precision and prevents small movements from changing the horn’s vertical relationship with the listener.
Vertical aiming matters because horn dispersion is usually more restricted in one plane than in the other. If the listener sits significantly above or below the acoustic axis, upper-midrange energy may change and the soundstage can lose height. Keep the main seat aligned with the design axis, then check nearby seats for acceptable coverage.
Control Boundaries And Reflections
Side walls strongly influence a bi-radial horn because the horizontal dispersion pattern determines when reflected energy arrives at the listening position. Greater distance from the side wall generally reduces early reflections and improves image separation. However, extremely wide spacing can make the centre image weak or leave the soundstage disconnected from the room.
A wall behind the listener can produce strong returns into the listening area. If the seat is close to that boundary, absorption or diffusion may improve focus. A thick rug between the speakers and listener can reduce floor reflections, while curtains, bookshelves, or broadband panels can moderate excessive brightness without making the room acoustically dead.
The crossover design also affects how placement is perceived. Sunship Audio’s approach to simple topologies aims to preserve phase coherence and signal integrity, so the system can respond clearly to changes in distance and angle. Keep the left and right acoustic paths as equal as possible.
Compare Placement Variables Systematically
Change one variable at a time and keep brief notes. Moving both speakers forward by 10 centimetres is more informative than shifting one cabinet randomly, since you can connect the resulting change with boundary interaction, bass loading, or image depth.
Begin with the broad geometry before adjusting toe-in. First find a balanced distance from the front wall, then set spacing, then refine the listening distance and horn angle. Bass-heavy recordings help assess boundary reinforcement, while well-recorded vocals and small ensembles reveal image focus and tonal neutrality.
| Placement variable | Common audible effect | Useful first adjustment |
|---|---|---|
| Distance from front wall | Changes bass weight and image depth | Move both speakers in 10 cm steps |
| Distance from side walls | Alters image width and reflection strength | Maintain equal spacing on both sides |
| Speaker spacing | Affects centre focus and stage scale | Start with an equilateral triangle |
| Toe-in angle | Changes presence, treble energy, and focus | Aim at the listener, then widen gradually |
| Horn height | Influences tonal balance and image elevation | Align the acoustic axis with ear level |
| Listening distance | Affects driver integration and coverage | Move back if the horns sound too direct |
Fine-Tune For The Room
Once the basic position is working, assess bass separately from the horn section. Low frequencies are affected by room modes and may not improve simply because the speakers are symmetrical. If bass is uneven across the listening seat, try moving the entire pair forward or backward before changing the speakers independently.
Listen at moderate volume first. Higher levels can make dynamics seem impressive while masking tonal problems caused by reflections or room modes. At a sensible level, check whether vocals remain centred, cymbals retain natural decay, and low notes have consistent pitch rather than a lingering boom.
Use familiar recordings with acoustic instruments, voice, and clean percussion. A strong placement should produce a stable phantom centre, believable depth behind the speakers, and smooth movement across the soundstage. It should also remain engaging when you shift slightly from the central seat.
Practical Setup Priorities
- Mark the initial positions with removable tape so every experiment can be reversed.
- Keep the speaker-to-listener distances equal within a few millimetres where possible.
- Adjust toe-in in small increments rather than making large angular changes.
- Use a laser, tape measure, or string to verify symmetry across the room.
- Give each placement several minutes of serious listening before judging it.
The final position may differ from textbook geometry because every room has its own proportions, furnishings, and acoustic behaviour. What matters is a repeatable process that respects the horn’s directivity and preserves symmetry. When placement is right, the loudspeaker disappears more easily, leaving the recording’s scale, texture, and dynamics in the foreground.
Arrange a listening session in Sunship Audio’s Berlin demonstration room to hear how a carefully integrated bi-radial horn system responds to room geometry, cabinet alignment, and considered setup. During installation, use the same method: begin symmetrically, make measured changes, and let the room reveal the position that gives the most natural performance.