Speaker box

You ask

Where do standing waves form in the air inside the box below 1 kHz?

Wobbl runs

Terminal

$ wobbl simulate box.step "where do standing waves form in the air inside the box below 1 kHz?" \  --assign "box: rigid" --fmax "1000 Hz" --no-open

The box driven at the frequency you pick, as the run left it at 331.1 Hz

Open the full report

Checks, numbers and charts

OKThe air has 4 standing wave modes below 1000 Hz, the lowest at 331 Hz and the next at 847 Hz.

Lowest mode: 331 Hz
Modes: 4 below 1,000 Hz
Air volume: 10.4 L
Confidence: low

failmesh convergence
passmode count

summary.txt

OK. The air has 4 standing wave modes below 1000 Hz, the lowest at 331 Hz and the next at 847 Hz. Confidence: low. mesh convergence failed: the first 4 modes moved at most 2.9% on the finer meshlowest mode: 331 Hzmodes: 4 below 1000 Hzair volume: 10.4 Lclose pairs: 0 Checks:  [fail] mesh convergence: the first 4 modes moved at most 2.9% on the finer mesh  [pass] mode count: 4 modes below 1000 Hz, where Weyl's formula for this volume and surface expects about 4 Assumptions:  - Sound hard walls with no absorption, air at 20 C (343 m/s). Real walls damp the modes, and the frequencies hold to about a percent.  - The air is the cavity inside 'box', taken from the CAD. Images: modes: images/modes.png, spectrum: images/spectrum.pngReport: report.html

Run it yourself

Terminal

$ git clone https://github.com/sohan-bhat/wobbl$ cd wobbl/examples/speaker-box && ./run.sh

The part, the script and every output are in examples/speaker-box on GitHub.