Acoustics & audio calculators that respect you
Free, fast, accurate, and permanently ad-free. Every tool shows its formulas, works on your phone, and produces a shareable link to your exact result.
Room mode calculator
Axial, tangential and oblique standing waves for any rectangular room, with problem-frequency flags.
Reverberation time (RT60)
Sabine and Eyring RT60 across six bands from your room's surfaces, with treatment suggestions.
Speaker crossover calculator
Passive 2-way component values — Butterworth, Linkwitz-Riley, Bessel — with schematic and E12 parts.
Speaker box calculator
Sealed and ported enclosure volumes, tuning and port length from Thiele/Small parameters.
Delay & BPM calculator
Note-value delay times, LFO rates, samples, and distance-to-milliseconds with tap tempo.
Why these tools
Most engineering calculators online are fifteen-year-old pages buried in ads. These are built the way a tool should be: instant results as you type, correct formulas shown in the open, sensible defaults, dark mode, and links you can share or bookmark with your numbers preserved. More tools ship regularly.