Professional Audio
Professional Speaker Placement Guide
Two identical sound systems can perform completely differently depending on how the speakers are placed. This guide explains the placement principles, height and angle calculations, and coverage patterns that determine whether an audience hears clear, even sound or a mix of dead spots and harsh reflections.
Understanding speaker dispersion
Every speaker has a horizontal and vertical dispersion angle, commonly 90x60 degrees or 60x40 degrees for point-source speakers, describing the area over which sound projects at consistent volume. Placing a speaker so its dispersion pattern matches the audience area, rather than pointing at walls or empty space, is the single biggest factor in even coverage.
Height and mounting
Speakers mounted too low get blocked by standing or seated audience members near the front, while speakers mounted too high can send too much energy over the heads of the front rows and onto the back wall, causing echo. A general starting point for a flat-floor venue is mounting the speaker's acoustic centre at least 2.4-3m above the floor, angled downward toward the back of the seating area.
Flying versus ground stacking
Flying (rigging) speakers overhead frees floor space and generally improves coverage consistency across a room, but requires certified rigging points and load calculations. Ground-stacked speakers on stands are simpler and cheaper to deploy but perform less evenly in rooms deeper than about 15-20 metres, since the source height relative to the audience is much lower.
Left-right spacing and stereo image
For music-focused events, keeping the same distance from each main speaker to the centre of the audience preserves stereo image, but perfect symmetry is often less important than consistent coverage for speech-focused venues like churches and conference halls, where intelligibility across the whole seating area matters more than stereo effect.
Delay speakers for large or deep rooms
In rooms deeper than about 20 metres, or with balconies, sound arriving late from the main speakers can cause echo for audience members far from the stage but close to a secondary speaker. Delay speakers, deliberately time-aligned in milliseconds to the main system using a digital processor, fix this by making the sound arrive as one coherent event rather than two separate echoes.
| Room depth | Recommended approach | Notes |
|---|---|---|
| Up to 15m | Single main PA pair | No delay speakers typically needed |
| 15m - 25m | Main PA plus one delay zone | Delay set using distance/speed of sound calculation |
| 25m+ or with balcony | Main PA plus multiple delay zones | Digital processor essential for accurate time alignment |
Subwoofer placement
Low frequencies are largely non-directional, but placement still affects bass evenness. Placing subwoofers together in the centre concentrates bass energy but can create uneven coverage side to side; spreading subwoofers left and right, or using a cardioid subwoofer arrangement, gives more even low-frequency coverage across the seating area and reduces stage bleed.
Avoiding feedback through placement
Feedback risk is significantly reduced simply by keeping the main speakers' dispersion pattern away from open microphones. Point-source speakers should generally be positioned ahead of the microphone line, not beside or behind it, so the loudest sound path never travels back through the microphone.
Quick placement test
Walk the full seating area during a system check with pink noise or music playing. Note any spot noticeably louder, quieter or muddier than its neighbours; these usually indicate a coverage gap, an overlap causing comb filtering, or a reflective surface needing treatment.
Outdoor speaker placement considerations
Outdoor events lack reflective walls and ceilings to help carry sound, so outdoor systems need higher power and tighter coverage planning than an equivalent indoor space. Wind can also physically affect line array angle over the course of a long outdoor event, so rigging should be checked periodically.
Placement planning steps
- Measure room depth, width and any balconies or deep seating areas
- Choose flown or ground-stacked configuration based on room size and rigging availability
- Calculate mounting height and downward angle to cover the full seating area
- Add delay speakers for rooms deeper than about 20 metres
- Position subwoofers for even low-frequency spread across the room
- Keep speaker dispersion patterns off open microphones
- Walk-test coverage with real content before the event
Frequently asked questions
How high should main PA speakers be mounted?+
A common starting point is 2.4-3 metres above the floor for the acoustic centre, angled down toward the back of the seating area, though exact height depends on room depth and ceiling height.
When do I need delay speakers?+
Delay speakers are typically needed in rooms deeper than about 20 metres or with balconies, where sound from the main system alone would arrive too late relative to a nearby secondary source, causing audible echo.
Should subwoofers be placed together or spread apart?+
Spreading subwoofers left and right, or using a cardioid arrangement, generally gives more even bass coverage across the room than clustering them together, though centre placement is simpler and works well for smaller venues.
Does speaker placement really affect feedback?+
Yes significantly. Positioning speakers so their sound projects forward and away from open microphones, rather than back over them, greatly reduces the amplified sound reaching the microphone and causing feedback.
Is it better to fly speakers or use stands?+
Flying speakers generally gives more consistent coverage in larger or deeper rooms and frees floor space, but requires certified rigging. Ground stacking is simpler and adequate for smaller rooms up to about 15-20 metres deep.
How do I check if my speaker coverage is even?+
Play familiar music or pink noise through the system and walk the entire seating area, listening for spots that sound noticeably louder, quieter or muddier than surrounding areas, which indicate a placement or overlap issue.