Room Modes & Standing-Wave Simulator

Rectangular rigid-wall approximation. Useful mainly for low-frequency room behaviour.

Room dimensions

Inspection frequency

Room materials

Avg LF absorption: 11%

Room summary

Nearest mode
(0, 1, 0)
42.88 Hz · Axial

Room volume
54
71 modes below 200 Hz · 0.4 modes/Hz

Estimated reverberation
0.9s
Controlled
Timber floor (joists) · Plaster on concrete / brick

Overall
Moderate acoustics

Mode spectrum by frequency

Each vertical line is one room mode. Tall grouped bars show frequency regions where several modes sit very close together.

What this room may sound like

Moderate acoustics. Noticeable bass colouration. mode stacking at 127, 133, 143 Hz. some notes will boom while others are weak. Sound is well-controlled with natural echo — good clarity for speech and music.

Strengths

  • + Ideal RT60 (0.9s)
  • + Good speech clarity

Things to watch

  • ! 3 region(s) with mode stacking
  • ! Low modal density

Key clusters: 126.9 Hz (3 modes); 133.1 Hz (3 modes); 143.5 Hz (3 modes)

Largest gap: 12.0 Hz max (avg 3.4 Hz)

Standing-wave pressure pattern — top view

Zero-crossings are pressure nodes. Strong positive/negative regions are pressure antinodes. The result changes with listener position and source position.

Strongest low-frequency trouble spots

FrequencyModes nearbyLikely effect
126.9 Hz3Noticeable reinforcement
133.1 Hz3Noticeable reinforcement
143.5 Hz3Noticeable reinforcement

Modes nearest selected frequency

nₓ, nᵧ, n_zHzTypeΔf
(0, 1, 0)42.88Axial-0.13
(1, 0, 0)34.30Axial-8.70
(1, 1, 0)54.91Tangential+11.91
(0, 0, 1)63.52Axial+20.52
(2, 0, 0)68.60Axial+25.60
(1, 0, 1)72.19Tangential+29.19
(0, 1, 1)76.63Tangential+33.63
(2, 1, 0)80.90Tangential+37.90
(1, 1, 1)83.96Oblique+40.96
(0, 2, 0)85.75Axial+42.75

How to interpret it for musical instruments

  • Mode peak: a played note near that frequency may become unnaturally loud and may ring longer.
  • Mode null: at some positions the same note can become surprisingly weak or almost disappear.
  • Closely spaced modes: bass can sound thick, muddy, or uneven because several resonances are excited together.
  • Large gaps between modes: nearby notes may lack support, creating a “one note booms, next note dies” effect.
  • Instrument consequence: cello, double bass, bass guitar, piano bass, timpani and low male voice reveal these problems most strongly.