YOUR ROOM.
EXPLORE THE DIFFERENCE.

The widget on this page gives an instant, theoretical estimate of how much AVAA active absorbers could shorten a room's low-frequency ringing (RT60), for any room size from 1 m to 100 m per axis. You set a room size and a wall reflectivity, switch on however many AVAA mount points you like (0 to 8), and the tool immediately shows how the room's own resonant frequencies (10–150 Hz) would decay with and without those absorbers — no simulation run, no waiting.

This tool makes active bass absorption’s effect visible and intuitive. Its simplified, closed-form model lets you explore room sizes, wall reflectivity, absorber counts and placement with instant feedback.

Below roughly 200–300 Hz, a room's own dimensions matter as much as what's playing through the speakers. Sound reflects off the walls, ceiling and floor and reinforces itself at specific frequencies — the room's modes. At those frequencies bass rings on long after the source stops, and how long it rings is exactly what RT60 measures.

Crucially, a room mode isn't uniformly loud everywhere: it has quiet points (nodes) and loud points (antinodes) fixed in space. An AVAA unit placed at an antinode of a given mode damps that mode strongly; the same unit at a node of that same mode does almost nothing to it — even though it may be doing a great deal of work on a different mode at a different frequency. This tool's per-mode RT60 estimate exists specifically to make that placement sensitivity visible, rather than collapsing it into one average number.

This widget runs no wave simulation at all. Everything is closed-form room-acoustics math, computed directly in your browser:

1. 1

   Room modes

   The exact resonant frequencies of an empty rigid box of your chosen size, from the same textbook formula used throughout acoustics — no grid, no time-stepping.

2. 2

   A decay rate per mode

   Each mode's own damping rate is estimated from how much of the room's absorptive boundary — walls plus any active AVAA units — that mode's standing-wave pattern actually overlaps, weighted by the pattern's strength at each absorber's exact position. This is what makes the estimate placement-sensitive rather than a single flat number.

3. 3

   RT60 from the decay rate

   Each mode's decay rate converts directly to an RT60 (time to decay 60 dB) for that mode, computed twice per mode — once with no absorbers active, once with your current selection — so the chart and table below show a direct, frequency- by-frequency comparison.

Set your room dimensions and wall reflectivity, choose AVAA positions, then explore the results. The following explains each part of the tool:

1. 1

   Set the room size

   Width, depth and height in meters, 1 to 100 on each axis. Very large rooms (tens of meters per side) can take slightly longer to update because finding modes in a dense low-frequency spectrum requires more searching.

2. 2

   Set wall reflectivity

   Under “Advanced settings”, a single absorption-coefficient slider, α, from 0 (perfectly rigid, left end) to 1 (perfect absorption/free air, right end). The advanced settings also display the equivalent acoustic impedance in Pa·s/m. The slider is log-scaled so most of its travel covers the reflective end where real wall materials actually sit; free air is compressed into a small stretch at the right, since it's more of a reference edge case than a real wall. Presets: Free air, Soft wall, Medium wall, Hard wall, or drag to set your own value.

   α=0 (rigid)α=1 (free air)
3. 3

   Check the room modes list

   Open “View detailed results” to see up to 10 resonant frequencies (10–150 Hz) for your current room size — these are exactly the frequencies shown in the results chart and table below.

4. 4

   Switch on absorbers

   Click mount points on the room diagram, or use “Choose positions by name” — four corners and four wall midpoints, up to 8 total, the same fixed-size (210 mm) AVAA unit at each. The stereo speaker pair and listening position shown in the diagram are a fixed reference triangle, centered on the room — position doesn't affect the estimate (see FAQ).

Results update live — there's no run button, and nothing to wait for.

The RT60 chart

One bar pair per room mode: grey (without AVAA) and red (with AVAA). On narrow screens, the pairs are shown horizontally with their values in seconds. A bar reaching the edge of the chart with an ∞ mark means that mode's decay is effectively unbounded within this model (typically a very rigid room with nothing active yet).

The mode table

Open “View detailed results” underneath the chart to see a row per mode: frequency and mode indices, RT60 with no absorbers, RT60 with your current selection, the difference (Δ), and the percentage gain that difference represents relative to the no-absorber value. A dash (–) in the Δ or gain column means one side isn't a finite number to compare against (e.g. the untreated room doesn't meaningfully decay within this model at all).

The summary line

A plain-language readout of which mode benefits most from your current placement, and by how much — useful as a quick headline before reading the full table.

Specifically, the model simplifies reality in several ways:

• Idealized geometry. The room is treated as an empty rectangular box. Furniture, doors, windows, alcoves and people all change real low-frequency behavior.
• One wall material for the whole room. All six surfaces share a single α value — worth remembering if your real room's floor, ceiling and walls differ a lot.
• Each absorber sampled at a single point. An AVAA unit's effect on a given mode is evaluated at its mount position and half its own height, not integrated across its full surface — a good approximation at these wavelengths (2–30+ m, far larger than the ~0.21 m unit), but still an approximation.
• Source and receiver position have no effect on the estimate. RT60 here is a property of the room, its walls, and absorber placement alone — not of where you'd stand or where the speakers face. The stereo triangle in the diagram is shown purely for visual reference.
• Assumes lightly-damped modes. The underlying math is a small-perturbation estimate, most accurate when the room isn't already extremely absorptive. Very high α values (near free air) push toward the edge of where this approximation is most reliable.

Treat every number here as illustrative of a tendency — that a mode exists at roughly this frequency, that absorber count and placement matter, that some modes benefit far more than others — rather than a value you'd quote for your own room. For an assessment of your actual space, consult an acoustics professional or PSI Audio directly.

Absorption coefficient (α)

A 0–1 measure of how much sound energy a surface absorbs at normal incidence: 0 = perfectly reflective, 1 = perfectly absorptive (matches air's own impedance). The advanced settings show both this coefficient and the corresponding acoustic impedance in Pa·s/m.

Specific acoustic impedance (Z₀)

The reference impedance of air itself (≈415 Pa·s/m at typical conditions) — the impedance a perfectly matched (α=1) surface would have.

Room mode / standing wave

A frequency at which a room's own dimensions cause sound waves to reinforce themselves, producing fixed loud points (antinodes) and quiet points (nodes) in space.

Node / antinode

A node is a point where a given mode's pressure is always near zero; an antinode is where it's strongest. An absorber's effect on a mode depends heavily on which one it sits near.

RT60

The time for a mode's sound energy to decay by 60 dB after the source stops — estimated here per mode from a closed-form decay-rate calculation, not measured directly.

Schroeder frequency

The rough frequency above which a room's modes overlap densely enough to be treated statistically (a single averaged RT60 becomes meaningful). Below it — typically true across this tool's whole 10–150 Hz range in small/medium rooms — individual modes dominate instead.

Absorber mount point

One of eight fixed positions — four corners, four wall midpoints — where a simulated AVAA unit can be switched on.