Metres · feet · °C · °F
Type your room’s length, width and height to see where it booms and where bass goes missing: every room mode up to 300 Hz, charted and checked.
4.2 × 3.4 × 2.4 m (13.78 × 11.15 × 7.87 ft) · 34.3 m³ (1,210 ft³) · sound at 343.3 m/s (1,126 ft/s), 20 °C (68 °F)
Widest gap below the Schroeder frequency: 50.5–65.0 Hz (14.5 Hz with no mode). Bands are third octaves; the number in each is its mode count up to the 200 Hz band. “Coincident” means the same frequency to 0.05 Hz.
| Band, Hz | Range, Hz | Modes |
|---|---|---|
| 40 | 35.5–44.7 | 1 |
| 50 | 44.7–56.2 | 1 |
| 63 | 56.2–70.8 | 1 |
| 80 | 70.8–89.1 | 4 |
| 100 | 89.1–112.2 | 5 |
| 125 | 112.2–141.3 | 6 |
| 160 | 141.3–177.8 | 19 |
| 200 | 177.8–223.9 | 30 |
Your room, height : width : length = 1 : 1.42 : 1.75
Within the ITU-R BS.1116-3 proportions for a reference listening room: 1.1·w/h ≤ l/h ≤ 4.5·w/h − 4 gives 1.56 ≤ 1.75 ≤ 2.38, with l/h = 1.75 and w/h = 1.42 both under 3.
| Name | Proportions | Source |
|---|---|---|
| Sepmeyer A | 1 : 1.14 : 1.39 | Sepmeyer 1965 |
| Sepmeyer B | 1 : 1.28 : 1.54 | Sepmeyer 1965 |
| Sepmeyer C | 1 : 1.60 : 2.33 | Sepmeyer 1965 |
| Louden | 1 : 1.40 : 1.90 | Louden 1971 |
| Hz | Type | L W H | Nearest note | |
|---|---|---|---|---|
| 40.9 | Axial | 1 0 0 | E1 −14¢ | |
| 50.5 | Axial | 0 1 0 | G#1 −48¢ | |
| 65.0 | Tangential | 1 1 0 | C2 −12¢ | |
| 71.5 | Axial | 0 0 1 | D2 −45¢ | |
| 81.7 | Axial | 2 0 0 | E2 −14¢ | close pair |
| 82.4 | Tangential | 1 0 1 | E2 −1¢ | close pair |
| 87.5 | Tangential | 0 1 1 | F2 +5¢ | |
| 96.1 | Tangential | 2 1 0 | G2 −34¢ | close pair |
| 96.6 | Oblique | 1 1 1 | G2 −25¢ | close pair |
| 101.0 | Axial | 0 2 0 | G#2 −48¢ | |
| 108.6 | Tangential | 2 0 1 | A2 −22¢ | close pair |
| 108.9 | Tangential | 1 2 0 | A2 −17¢ | close pair |
| 119.8 | Oblique | 2 1 1 | A#2 +47¢ | |
| 122.6 | Axial | 3 0 0 | B2 −12¢ | |
| 123.7 | Tangential | 0 2 1 | B2 +4¢ | |
| 129.9 | Tangential | 2 2 0 | C3 −12¢ | close pair |
| 130.3 | Oblique | 1 2 1 | C3 −7¢ | close pair |
| 132.6 | Tangential | 3 1 0 | C3 +23¢ | |
| 141.9 | Tangential | 3 0 1 | C#3 +41¢ | |
| 143.0 | Axial | 0 0 2 | D3 −45¢ | |
| 148.3 | Oblique | 2 2 1 | D3 +17¢ | close pair |
| 148.8 | Tangential | 1 0 2 | D3 +23¢ | close pair |
| 150.7 | Oblique | 3 1 1 | D3 +45¢ | close pair |
| 151.5 | Axial | 0 3 0 | D#3 −46¢ | close pair |
| 151.7 | Tangential | 0 1 2 | D#3 −44¢ | close pair |
| 156.9 | Tangential | 1 3 0 | D#3 +15¢ | close pair |
| 157.1 | Oblique | 1 1 2 | D#3 +17¢ | close pair |
| 158.8 | Tangential | 3 2 0 | D#3 +36¢ | |
| 163.5 | Axial | 4 0 0 | E3 −14¢ | |
| 164.8 | Tangential | 2 0 2 | E3 −1¢ | |
| 167.5 | Tangential | 0 3 1 | E3 +28¢ | |
| 171.1 | Tangential | 4 1 0 | F3 −35¢ | |
| 172.1 | Tangential | 2 3 0 | F3 −25¢ | close pair |
| 172.3 | Oblique | 2 1 2 | F3 −23¢ | close pair |
| 172.4 | Oblique | 1 3 1 | F3 −22¢ | close pair |
| 174.2 | Oblique | 3 2 1 | F3 −4¢ | close pair |
| 175.1 | Tangential | 0 2 2 | F3 +5¢ | close pair |
| 178.4 | Tangential | 4 0 1 | F3 +38¢ | |
| 179.8 | Oblique | 1 2 2 | F#3 −49¢ | |
| 185.4 | Oblique | 4 1 1 | F#3 +4¢ | close pair |
| 186.4 | Oblique | 2 3 1 | F#3 +13¢ | close pair |
| 188.4 | Tangential | 3 0 2 | F#3 +32¢ | |
| 192.2 | Tangential | 4 2 0 | G3 −34¢ | |
| 193.2 | Oblique | 2 2 2 | G3 −25¢ | |
| 194.9 | Tangential | 3 3 0 | G3 −10¢ | close pair |
| 195.1 | Oblique | 3 1 2 | G3 −8¢ | close pair |
| 201.9 | Axial | 0 4 0 | G#3 −48¢ | |
| 204.4 | Axial | 5 0 0 | G#3 −28¢ | close pair |
| 205.0 | Oblique | 4 2 1 | G#3 −22¢ | close pair |
| 206.0 | Tangential | 1 4 0 | G#3 −13¢ | |
| 207.6 | Oblique | 3 3 1 | G#3 −1¢ | close pair |
| 208.3 | Tangential | 0 3 2 | G#3 +6¢ | close pair |
| 210.5 | Tangential | 5 1 0 | G#3 +24¢ | |
| 212.3 | Oblique | 1 3 2 | G#3 +38¢ | |
| 213.8 | Oblique | 3 2 2 | A3 −50¢ | close pair |
| 214.2 | Tangential | 0 4 1 | A3 −46¢ | close pair |
| 214.6 | Axial | 0 0 3 | A3 −43¢ | close pair |
| 216.5 | Tangential | 5 0 1 | A3 −28¢ | close pairabove fs |
| 217.2 | Tangential | 4 0 2 | A3 −22¢ | close pairabove fs |
| 217.9 | Tangential | 2 4 0 | A3 −17¢ | close pairabove fs |
| 218.1 | Oblique | 1 4 1 | A3 −15¢ | close pairabove fs |
| 218.4 | Tangential | 1 0 3 | A3 −12¢ | close pairabove fs |
| 220.4 | Tangential | 0 1 3 | A3 +3¢ | above fs |
| 222.3 | Oblique | 5 1 1 | A3 +18¢ | close pairabove fs |
| 222.9 | Tangential | 4 3 0 | A3 +22¢ | close pairabove fs |
| 223.0 | Oblique | 4 1 2 | A3 +24¢ | close pairabove fs |
| 223.8 | Oblique | 2 3 2 | A3 +30¢ | close pairabove fs |
| 224.2 | Oblique | 1 1 3 | A3 +33¢ | close pairabove fs |
| 227.9 | Tangential | 5 2 0 | A#3 −39¢ | above fs |
| 229.3 | Oblique | 2 4 1 | A#3 −28¢ | close pairabove fs |
| 229.6 | Tangential | 2 0 3 | A#3 −26¢ | close pairabove fs |
| 234.1 | Oblique | 4 3 1 | A#3 +7¢ | above fs |
| 235.1 | Oblique | 2 1 3 | A#3 +15¢ | above fs |
| 236.3 | Tangential | 3 4 0 | A#3 +23¢ | close pairabove fs |
| 237.1 | Tangential | 0 2 3 | A#3 +30¢ | close pairabove fs |
| 238.9 | Oblique | 5 2 1 | A#3 +43¢ | close pairabove fs |
| 239.6 | Oblique | 4 2 2 | A#3 +47¢ | close pairabove fs |
| 240.6 | Oblique | 1 2 3 | B3 −45¢ | above fs |
| 241.7 | Oblique | 3 3 2 | B3 −37¢ | above fs |
| 245.2 | Axial | 6 0 0 | B3 −12¢ | above fs |
| 246.8 | Oblique | 3 4 1 | B3 −1¢ | close pairabove fs |
| 247.1 | Tangential | 3 0 3 | B3 +1¢ | close pairabove fs |
| 247.5 | Tangential | 0 4 2 | B3 +4¢ | close pairabove fs |
| 249.4 | Tangential | 5 0 2 | B3 +17¢ | close pairabove fs |
| 250.4 | Tangential | 6 1 0 | B3 +24¢ | close pairabove fs |
| 250.8 | Oblique | 1 4 2 | B3 +27¢ | coincidentabove fs |
| 250.8 | Oblique | 2 2 3 | B3 +27¢ | coincidentabove fs |
| 252.2 | Oblique | 3 1 3 | B3 +37¢ | close pairabove fs |
| 252.4 | Axial | 0 5 0 | B3 +38¢ | close pairabove fs |
| 254.4 | Tangential | 5 3 0 | C4 −49¢ | close pairabove fs |
| 254.5 | Oblique | 5 1 2 | C4 −48¢ | close pairabove fs |
| 255.4 | Tangential | 6 0 1 | C4 −41¢ | close pairabove fs |
| 255.7 | Tangential | 1 5 0 | C4 −40¢ | close pairabove fs |
| 259.8 | Tangential | 4 4 0 | C4 −12¢ | close pairabove fs |
| 260.4 | Oblique | 6 1 1 | C4 −8¢ | close pairabove fs |
| 260.6 | Oblique | 2 4 2 | C4 −7¢ | close pairabove fs |
| 262.4 | Tangential | 0 5 1 | C4 +5¢ | close pairabove fs |
| 262.6 | Tangential | 0 3 3 | C4 +7¢ | close pairabove fs |
| 264.2 | Oblique | 5 3 1 | C4 +17¢ | close pairabove fs |
| 264.8 | Oblique | 4 3 2 | C4 +21¢ | close pairabove fs |
| 265.2 | Tangential | 6 2 0 | C4 +23¢ | close pairabove fs |
| 265.3 | Tangential | 2 5 0 | C4 +24¢ | close pairabove fs |
| 265.5 | Oblique | 1 5 1 | C4 +26¢ | close pairabove fs |
| 265.8 | Oblique | 1 3 3 | C4 +27¢ | close pairabove fs |
| 267.0 | Oblique | 3 2 3 | C4 +35¢ | above fs |
| 269.1 | Oblique | 5 2 2 | C4 +49¢ | close pairabove fs |
| 269.5 | Oblique | 4 4 1 | C#4 −49¢ | close pairabove fs |
| 269.8 | Tangential | 4 0 3 | C#4 −47¢ | close pairabove fs |
| 274.4 | Oblique | 4 1 3 | C#4 −17¢ | close pairabove fs |
| 274.7 | Oblique | 6 2 1 | C#4 −16¢ | close pairabove fs |
| 274.8 | Oblique | 2 5 1 | C#4 −15¢ | close pairabove fs |
| 275.1 | Oblique | 2 3 3 | C#4 −13¢ | close pairabove fs |
| 276.2 | Oblique | 3 4 2 | C#4 −6¢ | above fs |
| 280.6 | Tangential | 3 5 0 | C#4 +21¢ | above fs |
| 283.9 | Tangential | 6 0 2 | C#4 +41¢ | above fs |
| 286.1 | Axial | 0 0 4 | D4 −45¢ | coincidentabove fs |
| 286.1 | Axial | 7 0 0 | D4 −45¢ | coincidentabove fs |
| 287.3 | Tangential | 5 4 0 | D4 −38¢ | close pairabove fs |
| 288.0 | Oblique | 4 2 3 | D4 −34¢ | close pairabove fs |
| 288.2 | Tangential | 6 3 0 | D4 −32¢ | close pairabove fs |
| 288.4 | Oblique | 6 1 2 | D4 −32¢ | close pairabove fs |
| 289.0 | Tangential | 1 0 4 | D4 −28¢ | close pairabove fs |
| 289.6 | Oblique | 3 5 1 | D4 −24¢ | close pairabove fs |
| 289.9 | Oblique | 3 3 3 | D4 −23¢ | close pairabove fs |
| 290.1 | Tangential | 0 5 2 | D4 −21¢ | close pairabove fs |
| 290.5 | Tangential | 7 1 0 | D4 −19¢ | coincidentabove fs |
| 290.5 | Tangential | 0 1 4 | D4 −19¢ | coincidentabove fs |
| 291.8 | Oblique | 5 3 2 | D4 −11¢ | above fs |
| 293.0 | Oblique | 1 5 2 | D4 −4¢ | close pairabove fs |
| 293.4 | Oblique | 1 1 4 | D4 −2¢ | close pairabove fs |
| 294.7 | Tangential | 0 4 3 | D4 +6¢ | close pairabove fs |
| 294.9 | Tangential | 7 0 1 | D4 +7¢ | close pairabove fs |
| 296.1 | Oblique | 5 4 1 | D4 +14¢ | close pairabove fs |
| 296.3 | Tangential | 5 0 3 | D4 +16¢ | close pairabove fs |
| 296.6 | Oblique | 4 4 2 | D4 +17¢ | close pairabove fs |
| 297.0 | Oblique | 6 3 1 | D4 +19¢ | close pairabove fs |
| 297.5 | Oblique | 1 4 3 | D4 +22¢ | close pairabove fs |
| 297.5 | Tangential | 2 0 4 | D4 +23¢ | close pairabove fs |
| 299.2 | Oblique | 7 1 1 | D4 +32¢ | above fs |
Sound bounces between the walls. At certain frequencies the reflections line up with the sound going the other way and build a standing wave, or room mode: loud in some places, almost silent in others. The calculator uses the standard formula for a rectangular room:
f = (c / 2) · √((nx / L)² + (ny / W)² + (nz / H)²)
where c is the speed of sound at your air temperature and nx, ny and nz are whole numbers. One non-zero number gives an axial mode between two opposite surfaces, usually the strongest; two give a tangential mode around four surfaces; three give an oblique mode involving all six.
Low down, modes are few and far apart, so single notes boom and others thin out. Higher up they crowd together until the room behaves evenly; the Schroeder frequency estimates where that happens. The Bonello check counts modes in third-octave bands: the counts should never fall from one band to the next, and no two modes should coincide. Here “coincide” means the same frequency to 0.05 Hz, a tolerance this calculator chooses; pairs under 1 Hz apart are ringed on the chart as well.
The formula assumes a closed box with rigid walls. Under a sloping attic roof, or with an open door, real modes shift, so treat the list as a guide and confirm by measuring.
Reverb, reflections, speakers, mics and files.
Sabine and Eyring RT60 per octave band, and the absorption a target needs.
Where to put side-wall and ceiling panels, on a printable plan.
Wall-bounce dips from your speaker distances, and the stereo triangle.
Delay, samples and notch frequencies from two mic distances, with a 3:1 check.
WAV and compressed file sizes, and how many hours fit on a card.
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Try WebTraceCheckThe low axial modes, between the room’s opposite surfaces. They are usually the strongest and the most widely spaced, so each one makes its note boom or vanish depending on where you sit. Look for two modes landing close together, and for wide gaps with none.
Your room’s own, measured or estimated. The 0.4 s default is only a starting value. The estimate changes with the square root, so doubling the reverb time raises the Schroeder frequency by about 41%.
Not necessarily. Bonello’s criterion is one published way to judge how evenly modes are spread, and it says nothing about treatment, furniture or where you sit. Use it to compare possible layouts or to spot a problem frequency, then measure.
Only roughly. The formula is for rectangular rooms, so a sloping roof shifts the modes in ways it cannot predict. Use the length and width of the floor and a typical ceiling height as a starting point, and confirm with a measurement.