¼: 4 ft 0.0 in
½: 8 ft 0.0 in
The Locolory toolkit / Acoustics & Audio
Room Mode & Standing Wave Calculator
Calculate axial, tangential, and oblique room modes from room dimensions. Visualize standing wave frequencies, room ratios, and acoustic bass nulls.
Room Mode & Standing Wave Calculator is a free browser-based utility that calculate axial, tangential, and oblique room modes from room dimensions; Visualize standing wave frequencies, room ratios, and acoustic bass nulls.
- Core logic: apply rectangular-room mode equations to length, width, and height harmonics and group nearby resonances.
No software download, login, or server upload required. Computations execute locally on device.
Rectangular room acoustic model
● Calculated locally
Example starting room—replace with finished interior dimensions.
Normalized room ratio1 : 1.50 : 2.00
Nearest published ratio: Louden · distance 0.14
Close to published ratioInside broad Bolt-area screen
Bolt result is a broad digitized-envelope screening aid, not an exact reproduction of the original curve or a performance guarantee.
Hover or tap a mode line for details
Axial · 18Tangential · 76Oblique · 81
First axial mode35.2 Hz
Modes below 300 Hz175
Coincident clusters47
Critical problem frequencies
Clusters contain two or more calculated modes within 1 Hz.
| Center | Modes | Indices | Spread |
|---|---|---|---|
| 290.2 Hz | 9 | (0,6,1) · (2,0,4) · (2,6,0) · (4,3,3) · (6,3,2) · (8,0,1) · (5,2,3) · (2,4,3) · (6,4,1) | 0.95 Hz |
| 281.9 Hz | 7 | (0,0,4) · (0,6,0) · (8,0,0) · (0,4,3) · (2,5,2) · (4,5,1) · (6,4,0) | 0.98 Hz |
| 157.4 Hz | 5 | (0,3,1) · (2,0,2) · (2,3,0) · (4,0,1) · (3,2,1) | 0.44 Hz |
| 199.1 Hz | 5 | (0,3,2) · (4,0,2) · (4,3,0) · (3,2,2) · (5,2,0) | 0.35 Hz |
| 211.1 Hz | 5 | (2,3,2) · (4,3,1) · (0,0,3) · (6,0,0) · (5,2,1) | 0.33 Hz |
| 253.6 Hz | 5 | (0,3,3) · (4,0,3) · (6,0,2) · (6,3,0) · (3,2,3) | 0.27 Hz |
| 257.4 Hz | 5 | (3,4,2) · (5,4,0) · (3,5,0) · (4,1,3) · (6,1,2) | 0.80 Hz |
| 283.7 Hz | 5 | (1,0,4) · (1,6,0) · (7,0,2) · (7,3,0) · (1,4,3) | 0.97 Hz |
| 292.7 Hz | 5 | (1,6,1) · (7,3,1) · (3,5,2) · (5,4,2) · (5,5,0) | 0.94 Hz |
| 140.8 Hz | 4 | (0,0,2) · (0,3,0) · (4,0,0) · (3,2,0) | 0.49 Hz |
| 234.2 Hz | 4 | (1,2,3) · (0,4,2) · (0,5,0) · (4,4,0) | 0.88 Hz |
| 244.8 Hz | 4 | (0,5,1) · (2,4,2) · (2,5,0) · (4,4,1) | 0.00 Hz |
| 273.2 Hz | 4 | (7,2,1) · (4,4,2) · (0,5,2) · (4,5,0) | 0.75 Hz |
| 298.5 Hz | 4 | (2,6,1) · (6,0,3) · (1,2,4) · (7,2,2) | 0.23 Hz |
| 175.8 Hz | 3 | (3,0,2) · (3,3,0) · (5,0,0) | 0.00 Hz |
| 215.8 Hz | 3 | (3,4,0) · (0,1,3) · (6,1,0) | 0.96 Hz |
Subwoofer / listening spot null guide
Boundary-fraction positions
Distances are measured inward from either opposing boundary. They flag symmetry positions worth avoiding or testing—not guaranteed null locations for every mode.
¼: 3 ft 0.0 in
½: 6 ft 0.0 in
¼: 2 ft 0.0 in
½: 4 ft 0.0 in
Understanding Axial vs Tangential vs Oblique room modes
Axial modes involve one opposing surface pair and generally carry the strongest individual low-frequency effect. Tangential modes involve two pairs of surfaces; oblique modes involve all three and are individually weaker but increasingly dense.
The often-repeated “80%” description is a practical emphasis, not a universal energy constant: axial modes deserve early attention because they are sparse and strong, while the exact response depends on source, listener, damping, and construction.
Using predictions with measurements
The Rayleigh model assumes a rigid rectangular enclosure. Doors, windows, flexible walls, alcoves, furnishings, and damping shift frequencies and decay. Use predictions to target measurements, not replace them.
Move speakers, subwoofers, and the listening position away from repeated half- and quarter-dimension relationships, then confirm peaks and nulls with a calibrated measurement microphone.
Published proportions
Optimal Studio Room Dimension Ratios Reference Table
Normalize the shortest dimension to 1. Ratios screen modal spacing; they do not replace acoustic design or measurement.
| Reference | Height : width : length | Interpretation |
|---|---|---|
| Louden | 1 : 1.40 : 1.90 | Highly ranked modal distribution |
| Sepmeyer A | 1 : 1.14 : 1.39 | Compact proportion |
| Sepmeyer B | 1 : 1.28 : 1.54 | Moderate floor ratio |
| Sepmeyer C | 1 : 1.60 : 2.33 | Longer-room proportion |
| Perfect cube | 1 : 1 : 1 | Strictly avoid coincident fundamentals |
| Simple multiples | 1 : 2 : 2 / 1 : 2 : 3 | Can stack harmonically related modes |
Your input shapes the next update
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Good questions. Clear answers.
What is a room mode in audio acoustics?
A room mode is a resonant standing-wave pattern whose wavelength fits between rigid room boundaries. At its frequency, position determines whether pressure reinforces into a peak or cancels toward a null. Rectangular-room predictions are most useful at low frequencies.
Why does bass disappear in the middle of my room?
The midpoint of a room dimension coincides with pressure nulls for some odd-order axial modes. A listening position at exactly half the room length, width, or height can therefore cancel specific bass frequencies even when those frequencies are loud near a boundary.
What room dimension ratios are best for a home studio?
There is no universal best ratio. Louden, Sepmeyer, Bolt, and later researchers identify ranges intended to distribute modes more evenly. Room volume, construction, openings, decay time, speaker placement, and treatment still matter; measure the finished room.
Can acoustic foam panels absorb low-frequency room modes?
Thin porous foam mainly absorbs mid and high frequencies and usually has little effect on deep bass. Low-frequency control generally needs thick broadband absorption, large corner traps, tuned absorbers, multiple subwoofers, and optimized source/listener placement.