How CarsSound works
Electric cars are quick and quiet. CarsSound gives yours a voice: a combustion engine that is generated live in your browser and reacts to the way you actually drive.
No recordings — the engine is built in real time
Most "engine sound" apps loop a few recorded clips and change their pitch. That always sounds artificial: the loop is audible, and the pitch shift turns a deep V8 into a chipmunk at high revs. CarsSound takes a different approach. It models what really happens inside an engine and calculates the sound tens of thousands of times per second.
A virtual crankshaft turns at the current rpm. Each time a cylinder fires, it sends a pressure pulse into the exhaust. The pulse travels down a simulated pipe, bounces off the far end and rings at the pipe's resonant frequencies, then passes through a muffler. The order and spacing of the cylinders decides the character: an even-firing inline six sounds smooth, while a cross-plane V8 fires two pulses close together into the same bank and produces its famous uneven burble.
On top of that come the details that make an engine feel alive: intake roar under load, turbo whistle and the hiss of a blow-off valve, supercharger whine, the crackle of afterfire when you lift off, and tiny random variations between combustion cycles so no two revolutions sound exactly the same.
From road speed to engine revs
Your car does not share its throttle position with the browser, so CarsSound works it out from movement:
- Speed. The browser's location service reports your speed several times a second. CarsSound prefers the receiver's own speed measurement, which reacts faster than speed calculated from positions, and smooths over the gaps between updates.
- Acceleration. From the last fraction of a second of speed readings it estimates how hard you are accelerating. Pressing harder means more engine load, which makes the sound louder and rougher.
- Virtual gearbox. A simulated transmission picks a gear for your speed, works out the matching rpm and shifts up and down like an automatic: early and smoothly when you cruise, late and aggressively when you accelerate hard. On the way down it blips the throttle to match revs.
- Engine braking and overrun. When you lift off, the engine keeps spinning with the throttle closed, sounding quieter and smoother, and may pop and crackle for a moment.
The result follows your driving within a fraction of a second when the car's location updates quickly. The GPS card in the app shows how many updates per second your browser delivers.
Try it without driving
The Test drive mode replaces GPS with on-screen pedals and a small physics model, so you can explore every engine while parked. The pedals are analog: the height where your finger rests sets how far the pedal is pressed. Hold to rev blips the engine in neutral, like at a traffic light.
Getting started in the car
- Park, open carssound.app in the car's browser and bookmark it.
- Pick a car from the garage at the bottom of the screen.
- Press the big START button and allow location access.
- Turn up the media volume. The engine plays through the car speakers like music.
Keep the volume at a level where you can still hear traffic, sirens and warning chimes, and set everything up before you drive.