Terms

Effective 8 October 2026. Last updated 8 October 2026.

Eigentone is a free page published by PaintedApp, LLC ("we"). By using it you agree to these terms. They are short because the page asks little of you and promises little more than it shows.

What the page is

Eigentone computes the resonant modes of a rigid, empty, rectangular box from three dimensions, using the formulas and sources named on the page. A real room has doors, windows, furniture and absorbing surfaces, and its modes are shifted and damped by all of them. The page shows where low-frequency problems can be; it is not a measurement of any room, and it is not professional acoustic, building or engineering advice. Do not rely on it for decisions where a mistake costs money or safety; measure the room, or ask an acoustician.

The tone

The page can play a sine tone at a mode's frequency. It starts only when you press the button, its level is capped, and it stops by itself after 60 seconds. Keep your volume at a comfortable level; low frequencies can be loud on large speakers and subwoofers even when they sound quiet on small ones.

No charge, no account

The page is free and asks for no account and no payment. We may change it, move it or take it down at any time, without notice.

The code

The page's source code is released under the MIT licence. The sources it cites remain the work of their authors and publishers, and are named on the page and in the source repository.

No warranty

The page is provided as it is, without warranty of any kind, express or implied, including fitness for a particular purpose. Its receipts show where it agrees with its published sources and by how much; they are not a guarantee.

Limit of liability

To the extent the law allows, PaintedApp, LLC is not liable for any loss or damage arising from the use of the page, of its tone, or of anything computed by it.

Contact

PaintedApp, LLC: support@painted.app.