bug: Spectroscope inversely scales with volume

[valknight]

(apologies, didn't see a bug format on this repo, so copying what I use elsewhere!)

Summary

Spectroscope inversely scales with volume, such that reducing the volume will cause the spectroscope to visualise a much higher volume.

Steps to reproduce

1. Start a stream (e.g. cargo run -- play s340893)
2. Change volume by holding the up arrow key
3. Change volume by holding the down arrow key

Expected behaviour

Spectroscope either remains consistent (e.g. does not inversely scale with volume), or, has a reduced magnitude when approaching 0% volume

Actual behaviour

Spectroscope is inversely scaling, such that higher volumes show a lower magnitude, and 0% volume leads to incredibly high magnitudes on the spectroscope

Please see attached video showing this behaviour

out.mp4

Reproduction environment

macOS Tahoe 26.2, running on M4 Max. Also reproduces on Framework Laptop 13 (with Ryzen 5 7640U) running elementaryOS 8.1.