Room Modes in an 11x14 ft Room with a 9 ft Ceiling
This 11x14 ft room, 9 ft to the ceiling, is a common size for a bedroom theater or dedicated music room. Like any sealed box it resonates at fixed low notes; the lowest one lands at 40.2 Hz, driven by the 14 ft length.
On the 0-100 modal score, this room comes in at 85, a strong score for an untreated room. Before you treat anything, know that there is a gap of 11.3 Hz between 51.2 Hz and 62.5 Hz with no mode in between.
Mode spectrum
7 dense clusters (≤5 Hz apart) — overlapping resonances are harder to treat evenly.
Each line is one standing wave. Axial modes, the strongest kind, stand tallest; tight bunches and wide empty stretches are where the bass will sound uneven.
Axial modes by dimension
| Dimension | 1st | 2nd | 3rd | 4th |
|---|---|---|---|---|
| Length (14 ft) | 40.2 Hz | 80.4 Hz | 120.6 Hz | 160.8 Hz |
| Width (11 ft) | 51.2 Hz | 102.3 Hz | 153.5 Hz | 204.6 Hz |
| Ceiling height (9 ft) | 62.5 Hz | 125 Hz | 187.6 Hz | 250.1 Hz |
What this means for your room
- The lowest room mode is 40.2 Hz, set by the 14 ft length.
- Between 51.2 Hz and 62.5 Hz there are no modes at all, so notes in that 11.3 Hz gap will sound thinner than the bass around them.
- The proportions (1 : 1.22 : 1.56) fall outside the Bolt area because the room is long and narrow for its height, so modes bunch up along the length.
- Below about 202 Hz (the Schroeder frequency) individual modes shape the sound; above it, reflections and reverb matter more.
No mode falls between 51.2 Hz and 62.5 Hz, a gap of 11.3 Hz. That is a spot where bass naturally loses energy instead of gaining it.
In a home theater, this shows up as one bass note in an action scene sounding far louder than the rest of the mix, usually a kick drum hit or an LFE cue landing right on that gap. In a music room, the same thing means certain bass notes on a track jump out while others next to them feel buried.
At 1 : 1.22 : 1.56, this room sits outside the Bolt area because the room is long and narrow for its height, which bunches modes up along the length. Expect to lean on bass traps and seat position a bit more than in a room with friendlier proportions.
How to fix it, in order
- Treat the four floor-to-ceiling corners first; they are common to every mode this room produces.
- At 40.2 Hz the quarter wavelength is about 7 ft, deeper than any practical panel, so a porous trap alone will not fully absorb that note. Build corner traps as thick as you can fit (6 to 12 in, straddling the corner with an air gap behind) to take the edge off, then handle the note itself with a membrane or pressure trap tuned near it, careful seat position, and more than one subwoofer with EQ.
- Move your listening position off-center along the 14 ft length; roughly 5.3 ft from the front wall (38% back) is a common starting spot before fine-tuning.
- Walk the subwoofer around the front of the room while playing a bass-heavy track and listen from your seat: corner placement is loudest but least even, and a second sub or an off-corner spot often fills in this room’s weak points.
- Once traps are in, measure with REW from the listening position. Focus on frequencies below 202 Hz (this room's Schroeder frequency); that is where individual modes, not general reverb, are running the show.
These numbers assume an empty rectangular 11x14 room with hard walls. Draw your real room, add furniture and speakers, and simulate the bass at your seat.
Every mode below 200 Hz
The table below lists every mode under 200 Hz for this room: 51 in all, 10 axial, 26 tangential and 15 oblique. Axial modes bounce between just two parallel surfaces (say, the two side walls) and are the loudest and most audible; tangential modes involve four surfaces and are quieter; oblique modes bounce off all six surfaces and are the faintest. Start with the axial rows; they cause most of the boomy or thin spots you will actually hear.
| Frequency | Type | Mode (length, width, height) |
|---|---|---|
| 40.2 Hz | axial | (1,0,0) |
| 51.2 Hz | axial | (0,1,0) |
| 62.5 Hz | axial | (0,0,1) |
| 65.1 Hz | tangential | (1,1,0) |
| 74.3 Hz | tangential | (1,0,1) |
| 80.4 Hz | axial | (2,0,0) |
| 80.8 Hz | tangential | (0,1,1) |
| 90.2 Hz | oblique | (1,1,1) |
| 95.3 Hz | tangential | (2,1,0) |
| 101.8 Hz | tangential | (2,0,1) |
| 102.3 Hz | axial | (0,2,0) |
| 109.9 Hz | tangential | (1,2,0) |
| 114 Hz | oblique | (2,1,1) |
| 119.9 Hz | tangential | (0,2,1) |
| 120.6 Hz | axial | (3,0,0) |
| 125 Hz | axial | (0,0,2) |
| 126.4 Hz | oblique | (1,2,1) |
| 130.1 Hz | tangential | (2,2,0) |
| 131 Hz | tangential | (3,1,0) |
| 131.3 Hz | tangential | (1,0,2) |
| 135.1 Hz | tangential | (0,1,2) |
| 135.8 Hz | tangential | (3,0,1) |
| 140.9 Hz | oblique | (1,1,2) |
| 144.3 Hz | oblique | (2,2,1) |
| 145.1 Hz | oblique | (3,1,1) |
| 148.6 Hz | tangential | (2,0,2) |
| 153.5 Hz | axial | (0,3,0) |
| 157.2 Hz | oblique | (2,1,2) |
| 158.1 Hz | tangential | (3,2,0) |
| 158.6 Hz | tangential | (1,3,0) |
| 160.8 Hz | axial | (4,0,0) |
| 161.6 Hz | tangential | (0,2,2) |
| 165.7 Hz | tangential | (0,3,1) |
| 166.5 Hz | oblique | (1,2,2) |
| 168.7 Hz | tangential | (4,1,0) |
| 170 Hz | oblique | (3,2,1) |
| 170.5 Hz | oblique | (1,3,1) |
| 172.5 Hz | tangential | (4,0,1) |
| 173.2 Hz | tangential | (2,3,0) |
| 173.7 Hz | tangential | (3,0,2) |
| 179.9 Hz | oblique | (4,1,1) |
| 180.4 Hz | oblique | (2,2,2) |
| 181.1 Hz | oblique | (3,1,2) |
| 184.2 Hz | oblique | (2,3,1) |
| 187.6 Hz | axial | (0,0,3) |
| 190.6 Hz | tangential | (4,2,0) |
| 191.8 Hz | tangential | (1,0,3) |
| 194.4 Hz | tangential | (0,1,3) |
| 195.2 Hz | tangential | (3,3,0) |
| 197.9 Hz | tangential | (0,3,2) |
| 198.5 Hz | oblique | (1,1,3) |
Questions about 11x14 rooms
- Is an 11x14 room good for a home theater?
- At 154 sq ft, this size works well as a bedroom theater or dedicated music room, and its modal score of 85/100 is solid for an untreated room. Expect only minor bass trapping to clean up.
- Where do bass traps go in an 11 by 14 ft room?
- Start in the four floor-to-ceiling corners; every mode in this room peaks there. The 40.2 Hz mode itself would need about 7 ft of depth to fully absorb, more than any panel can give, so build corner traps as thick as you can fit (6 to 12 in) and pair them with a membrane trap tuned near 40.2 Hz.
- Do I need a big subwoofer for an 11x14 room?
- Room size here mainly shapes where the modes land, not the sub size on its own; this room has 51 modes below 200 Hz to work around either way. Larger rooms like this one ask more of a subwoofer's output, and a second sub in a different spot helps smooth out the peaks and dips across seats.
- Why do some bass notes sound weak in an 11x14 room?
- In this room, the main cause is that there is a gap of 11.3 Hz between 51.2 Hz and 62.5 Hz with no mode in between. Room modes reinforce specific notes more than others no matter how good your speakers are, and that unevenness is what you are hearing.
- How many bass traps does an 11 by 14 ft room need?
- Start by treating the four corners with traps as thick as you can fit (6 to 12 in) plus a membrane trap tuned near 40.2 Hz, since that note's own quarter wavelength (about 7 ft) is too deep for any panel. Next, shift your listening position toward 5.3 ft from the front wall, then confirm progress with an REW sweep under 202 Hz.
Similar room sizes
How these numbers are calculated
Modes use the rectangular-room equation f = (c/2)·√((nx/L)² + (ny/W)² + (nz/H)²) with c = 343 m/s, for an empty room with rigid walls. The Schroeder frequency is fs = 2000 x sqrt(RT60 / V), assuming RT60 = 0.4 s. The modal score starts at 100 and subtracts penalties for stacked modes, density dips, gaps, proportions outside the Bolt area and dimension multiples. Doors, openings and furniture shift real rooms away from these values, which is what the room mode calculator and the 3D editor are for.