Room Modes in an 11x19 ft Room with an 8 ft Ceiling
At 11 by 19 ft with an 8 ft ceiling, this room works well as a bedroom theater or dedicated music room. Its first room mode, the lowest note the walls naturally reinforce, falls at 29.6 Hz, set by the 19 ft length.
That puts its modal score at 65 out of 100, a decent score, typical for a room this shape. The main thing to plan around: there is a gap of 21.6 Hz between 29.6 Hz and 51.2 Hz with no mode in between.
Mode spectrum
8 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 (19 ft) | 29.6 Hz | 59.2 Hz | 88.8 Hz | 118.5 Hz |
| Width (11 ft) | 51.2 Hz | 102.3 Hz | 153.5 Hz | 204.6 Hz |
| Ceiling height (8 ft) | 70.3 Hz | 140.7 Hz | 211 Hz | 281.3 Hz |
What this means for your room
- The lowest room mode is 29.6 Hz, set by the 19 ft length.
- Between 29.6 Hz and 51.2 Hz there are no modes at all, so notes in that 21.6 Hz gap will sound thinner than the bass around them.
- Mode density drops in the 40 Hz third-octave band (0 modes against 1 in the band below), so bass will sound uneven from note to note.
- The proportions (1 : 1.38 : 2.38) fall outside the Bolt area because the room is long and narrow for its height, so modes bunch up along the length.
- Below about 184 Hz (the Schroeder frequency) individual modes shape the sound; above it, reflections and reverb matter more.
Between 29.6 Hz and 51.2 Hz there is no mode to reinforce anything, a gap of 21.6 Hz. Notes that fall in that gap sound thinner and quieter than notes just above or below it.
If you use this room for movies, that gap tends to show up as boom on specific low-frequency effects rather than an even rumble. If it is a music or mixing room, that same spot makes some bass notes read louder on playback than they actually are on the recording, which makes mixing bass by ear risky here.
This room's ratio (1 : 1.38 : 2.38) is outside the Bolt area: the room is long and narrow for its height, which bunches modes up along the length. Treatment can still get it sounding good, but the shape is not helping as much as it could.
How to fix it, in order
- Put your first traps in the four vertical corners where floor meets ceiling; that is where every mode in this room reaches its loudest point.
- At 40.0 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.
- Avoid the exact middle of the 19 ft length for your seat or mix position; try around 7.2 ft from the front wall (38% of the length) as a starting point, then nudge from there by ear.
- Test more than one subwoofer position. Corner placement drives the most output but also the least even bass; moving it along a wall or using two subs at different spots tends to average out this room’s peaks.
- Confirm the fix with an REW measurement at the listening position, paying closest attention below 184 Hz; above that, general room reverb matters more than any single mode.
These numbers assume an empty rectangular 11x19 room with hard walls. Draw your real room, add furniture and speakers, and simulate the bass at your seat.
Every mode below 200 Hz
This room has 62 modes below 200 Hz, 11 axial, 30 tangential and 21 oblique. Read the axial rows as the ones you will hear most clearly. Tangential and oblique modes add texture but usually only become audible when they land close to an axial mode.
| Frequency | Type | Mode (length, width, height) |
|---|---|---|
| 29.6 Hz | axial | (1,0,0) |
| 51.2 Hz | axial | (0,1,0) |
| 59.1 Hz | tangential | (1,1,0) |
| 59.2 Hz | axial | (2,0,0) |
| 70.3 Hz | axial | (0,0,1) |
| 76.3 Hz | tangential | (1,0,1) |
| 78.3 Hz | tangential | (2,1,0) |
| 87 Hz | tangential | (0,1,1) |
| 88.8 Hz | axial | (3,0,0) |
| 91.9 Hz | tangential | (2,0,1) |
| 91.9 Hz | oblique | (1,1,1) |
| 102.3 Hz | axial | (0,2,0) |
| 102.5 Hz | tangential | (3,1,0) |
| 105.2 Hz | oblique | (2,1,1) |
| 106.5 Hz | tangential | (1,2,0) |
| 113.3 Hz | tangential | (3,0,1) |
| 118.2 Hz | tangential | (2,2,0) |
| 118.5 Hz | axial | (4,0,0) |
| 124.1 Hz | tangential | (0,2,1) |
| 124.3 Hz | oblique | (3,1,1) |
| 127.6 Hz | oblique | (1,2,1) |
| 129 Hz | tangential | (4,1,0) |
| 135.5 Hz | tangential | (3,2,0) |
| 137.6 Hz | oblique | (2,2,1) |
| 137.8 Hz | tangential | (4,0,1) |
| 140.7 Hz | axial | (0,0,2) |
| 143.7 Hz | tangential | (1,0,2) |
| 147 Hz | oblique | (4,1,1) |
| 148.1 Hz | axial | (5,0,0) |
| 149.7 Hz | tangential | (0,1,2) |
| 152.6 Hz | tangential | (2,0,2) |
| 152.6 Hz | oblique | (1,1,2) |
| 152.7 Hz | oblique | (3,2,1) |
| 153.5 Hz | axial | (0,3,0) |
| 156.3 Hz | tangential | (1,3,0) |
| 156.5 Hz | tangential | (4,2,0) |
| 156.7 Hz | tangential | (5,1,0) |
| 161 Hz | oblique | (2,1,2) |
| 163.9 Hz | tangential | (5,0,1) |
| 164.5 Hz | tangential | (2,3,0) |
| 166.4 Hz | tangential | (3,0,2) |
| 168.8 Hz | tangential | (0,3,1) |
| 171.4 Hz | oblique | (1,3,1) |
| 171.6 Hz | oblique | (4,2,1) |
| 171.7 Hz | oblique | (5,1,1) |
| 173.9 Hz | tangential | (0,2,2) |
| 174.1 Hz | oblique | (3,1,2) |
| 176.4 Hz | oblique | (1,2,2) |
| 177.3 Hz | tangential | (3,3,0) |
| 177.7 Hz | axial | (6,0,0) |
| 178.9 Hz | oblique | (2,3,1) |
| 180 Hz | tangential | (5,2,0) |
| 183.7 Hz | oblique | (2,2,2) |
| 183.9 Hz | tangential | (4,0,2) |
| 184.9 Hz | tangential | (6,1,0) |
| 190.8 Hz | oblique | (3,3,1) |
| 190.9 Hz | oblique | (4,1,2) |
| 191.1 Hz | tangential | (6,0,1) |
| 193.2 Hz | oblique | (5,2,1) |
| 193.9 Hz | tangential | (4,3,0) |
| 195.3 Hz | oblique | (3,2,2) |
| 197.8 Hz | oblique | (6,1,1) |
Questions about 11x19 rooms
- Is an 11 by 19 ft room good for a music room or home theater?
- It can work as a bedroom theater or dedicated music room, but do not expect an easy ride: this room scores 65/100 because there is a gap of 21.6 Hz between 29.6 Hz and 51.2 Hz with no mode in between. Treatment will make a real difference here.
- What is the best corner for bass traps in an 11x19 room?
- Start in the four floor-to-ceiling corners; every mode in this room peaks there. The 40.0 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 40.0 Hz.
- What size subwoofer does an 11x19 room need?
- Subwoofer size is less about this room's 209 sq ft and more about the output headroom you want; room size mainly changes where the 62 modes below 200 Hz fall. A room this size needs more sub output to reach the same level as a smaller one, and running two subs at different spots evens out the response between seats.
- Why does bass sound thin in spots in an 11 by 19 ft room?
- Here it comes down to this: there is a gap of 21.6 Hz between 29.6 Hz and 51.2 Hz with no mode in between. That is a property of the room's shape, not your equipment, so treatment, not a better sub, is the fix.
- What is the fastest fix for bass in an 11x19 room?
- Corner bass traps come first, as thick as you can fit (6 to 12 in) plus a membrane trap tuned near 40.0 Hz, since that note's own quarter wavelength (about 7 ft) is too deep for any panel. After that, reposition your seat near 7.2 ft from the front wall and verify with REW below 184 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.