When you push a driver cone, three forces fight back: the air in front of it, the suspension holding it, and the cone’s own inertia. The stiffer the cone material, the less it flexes — and the more accurately it reproduces the signal.
Beryllium has a stiffness-to-weight ratio that makes aluminum look like wet cardboard. It’s the reason our 40mm driver tracks transients that aluminum cones smear.
The cost is real. Raw beryllium runs $12 per gram. Our machining process loses 60% of the material. But the alternative — a softer cone with corrective DSP — is a compromise we refuse to make.
The measurement
In our anechoic chamber, the beryllium cone shows THD below 0.02% at 90 dB SPL across the full audible band. The aluminum reference cone we tested alongside it measured 0.08% — four times worse.
| Metric | Beryllium | Aluminum |
|---|---|---|
| THD @ 90dB | 0.02% | 0.08% |
| Stiffness (GPa) | 287 | 69 |
| Density (g/cm³) | 1.85 | 2.70 |
What you hear
Cleaner transients. Percussion hits with attack and decay you can feel. Strings with overtones that ring true instead of muddy.
This isn’t marketing. It’s physics.