Audio feedback & variometer

For free-flight pilots, sound is essential — you need to know whether you're climbing or sinking without looking at the screen. The app provides a built-in variometer with audio tones.

Variometer audio

The variometer turns your vertical speed into sound: a rising tone when you climb, a sink tone when you descend. You can:

• Enable or disable the vario sound.
• Set the sink threshold at which the sink tone begins.
• Adjust sensitivity and volume.

The vario can be driven by the phone's barometric sensor, or by a connected Bluetooth vario for higher precision. See Bluetooth varios & GPS.

Why our variometer beats dedicated devices

Many pilots assume a standalone instrument like a Syride, Flymaster or Skytraxx must outperform their phone. That's no longer true. Our variometer is more precise, more sensitive and more responsive than most commercial devices — and here's why.

Newer, far more powerful hardware

• Latest-generation pressure sensors. The MEMS barometers built into recent smartphones deliver resolution on the order of a tenth of a pascal, i.e. altitude sensitivity down to a few centimetres. A free-flight instrument designed two or three years ago carries a previous-generation sensor. Your phone is often six months newer than the latest model any instrument maker has shipped.
• Computing power on another scale. A dedicated instrument runs on a microcontroller clocked at a few dozen MHz with a few kilobytes of memory. Your smartphone packs a multi-core processor at several GHz and multiple gigabytes of RAM. That headroom lets us apply far finer filtering without ever adding latency.
• High-frequency sampling. We read the phone's barometer at a very high rate (up to several dozen readings per second), where many dedicated devices throttle to a lower frequency to save battery. More readings = faster, finer detection of lift.

Smarter signal processing

• Multi-stage filtering. Our vertical speed runs through a low-pass filter coupled with outlier rejection: noise spikes (sensor turbulence, jolts) are removed, but the real signal — the onset of a thermal — passes through immediately. You get a tone that's stable without being sluggish.
• Sensor fusion. We combine the barometer, GPS and, when available, data from a BLE instrument. The app continuously selects the best altitude source — something a single sensor simply can't do.
• Hysteresis thresholds. The tone's on and off thresholds are separate, so the beep doesn't "chatter" around zero when you hover near the threshold — sound triggers only when you're genuinely climbing.

Always up to date, never obsolete

• Regular software updates. A dedicated instrument freezes its behaviour the day it ships. Our variometer keeps improving: we refine the algorithms, the tone and the responsiveness with every release. Your hardware doesn't age — it gets better.
• New phone, new vario. Every time you upgrade your smartphone you get newer sensors and processors for free — no need to buy another instrument worth several hundred euros.

TIP

For the absolute highest precision (and operation even with gloves, off-screen), you can still connect a dedicated BLE variometer. The app will then use it as the priority source — the best of both worlds.

Where the data comes from

• Phone barometer — many phones have a pressure sensor the app can use for altitude and vario.
• BLE instruments — devices like VectorVario, XCTracer, UltraBip and BlueBip stream high-quality vario, airspeed and wind data.

General audio feedback

Beyond the vario tones, the Android app can speak your metrics aloud — altitude, distance, time, speed and more — on a timer, every few kilometres, or when you hit a target, with custom voice messages. That's a separate feature: see Audio feedback (spoken metrics).

INFO

Variometer audio on connected devices is part of Premium on Android.