ACOUSTICS · ARCHITECTURE · WAVE PHYSICS

Resonance.

Hear how your position changes a sample room’s sound.

New: enter the listening room — move sound and hear real early reflections ↗

Selected resonance

71.46Hz

(2, 1, 0)tangentialSample room · ideal model · 343 m/s

Positive pressureNegative pressureNode

Pressure on a horizontal section at 1.20 m. Frozen phase; colors show the sign, not safe or unsafe.

Source → listener26.4%

Coupling to this mode

Both positions intersect this mode. Move toward a dashed node line to reduce its coupling.

Move the listener, then place it at a node. The selected resonance loses its coupling there.

Shape the room

Width6 m

Depth4 m

Height2.8 m

Mode study

Indices count pressure half-waves along width, depth and height.

Change your position

Move

Listener across width3.72 m

Listener along depth2.8 m

Listener height1.2 m

Room edits keep both positions in the same relative place. The section follows listener height.

Hear the relationship

A synthesized sine. Coupled gain follows the percentage; Reference uses a constant gain. Small speakers may not reproduce low bass.

A room carries more than one note

The neighboring resonances.

First 24 modes below 220 Hz

Each bar shows coupling to that mode relative to its own antinode placement. These bars are not a combined frequency response.

Inside the instrument

Geometry gives
sound somewhere to stand.

Two reflected waves can reinforce or cancel. In an ideal rectangular room, the boundaries constrain which pressure patterns can persist.

f = c/2 √[(n_x/L_x)² + (n_y/L_y)² + (n_z/L_z)²]

L is each room dimension; n is its mode index. Larger dimensions lower the matching resonance frequencies.

What this study can tell you

Explore why changing a listening position can change a bass note. Compare room dimensions, identify candidate modes, and export the model before making a measurement.

What remains outside the model

Real rooms absorb sound and contain furniture, openings and multiple simultaneous modes. The percentage is normalized modal coupling, not loudness, sound quality, or a treatment recommendation. The visual field is pressure, not moving air particles.

The source weights the displayed pressure pattern. A faint field can come from weak excitation at the source.

Penn State · Driving room modes ↗DTU · Room boundaries and model limits (2026 preprint) ↗

Take the experiment with you.

JSON preserves the scenario and assumptions. CSV carries the computed spectrum.

Full model assumptions

Ideal rectangular room with perfectly rigid, reflecting walls and sound speed fixed at 343 m/s.
One undamped mode at a time. The field is normalized pressure shape, not sound pressure level or particle displacement.
Coupling is the absolute product of the mode shape at a point source and a point listener, relative to antinode placement for this mode only.
No absorption, furniture, open doors, direct sound, transducer response, or measured room response. A modal node is not silence at all frequencies.
Audio is a synthesized reference sine with an optional coupling gain. It is not an auralization or a measurement of your room.

The person behind the project

A note from Luis.

I like the point where physics, geometry, and architecture become something you can experience. This study lets you hear one idealized room mode. The dimensions are a sample, not measurements of my room.

Who it helps

Curious listeners exploring the relationship between a room and sound.

Try this

Start the tone, then place the listener at a node. Hear that mode become quieter while its frequency stays the same.

Explore how a structure carries force