One curve, two backends

Two platforms, two entirely different audio engines, one stored setting. It only survives the trip if the definition — centres, width, range — lives in one place and both backends are proven against a third, neutral implementation. "It sounds about right on both" is not a check; the whole point of a stored curve is that a value dialled in on one device transfers to another.

Pin the definition where both sides can quote it, and make the second definition point at the first:

/**
 * The ten band centres, in Hz. Identical to the constant the other backend passes to its own
 * filter, and to the centres a published fixed-band profile set is generated at — up to the
 * rounding that set applies to its two lowest bands when it writes them out — so one stored curve
 * means the same thing on both platforms and an imported profile lands on the bands it was
 * computed for.
 */
val EQUALIZER_BANDS_HZ = intArrayOf(31, 62, 125, 250, 500, 1_000, 2_000, 4_000, 8_000, 16_000)