A sound stage for your car speakers

Engine sound through your car stereo.

WattGrowl plays its engine through the speakers your car already has. Connect your phone over Bluetooth, USB or a cable, and the Sound Studio puts the exhaust and pops behind you, the intake and turbo in front, and the exhaust bass in the subwoofer.

iPhone Coming soon

Bluetooth, USB or cable
Exhaust behind you
Subwoofer bass
Latency compensation

Sound stage set to Car surround: exhaust to engine balance at +2.0 dB, exhaust steered 100% to the rear, behind-you feel at 50% and exhaust bass to the subwoofer at +3.0 dB

Connect

Hook it up like a playlist.

No amplifier, no extra speakers, no wiring. Any car stereo your phone plays music through will do.

Connect the phone

Bluetooth, USB or an aux cable, whichever your head unit offers, selected as you would for music.

Set the stage

In the Sound Studio pick Car speakers or Car surround, a listening position and a mix, while you are parked.

Drive

Leave the phone in its mount. In Live drive it keeps playing hands-free with the screen off.

Sound stage

The exhaust belongs behind you.

In a gas car the noise comes from two ends: intake and engine up front, tailpipes at the back. The sound stage splits the engine into its parts and puts them back around you.

Choose Car speakers for a regular stereo, Car surround for a surround head unit, or Off. Then fine-tune:

Exhaust ↔ engine balance: more tailpipe or more engine.
Steer exhaust to the rear: on a surround head unit, the full steer sends it to the rear speakers.
Behind-you feel: how strongly the exhaust seems to come from behind.
Exhaust bass to subwoofer: the low rumble goes to the sub, if you have one.

One phone speaker cannot place sound, so there the stage is off.

Listening position

Driver's seat, curbside or under the hood.

The stage decides which speaker plays what; the listening position decides how the engine sounds from where you are:

Cabin: "Through the firewall: warm, bassy, a little muffled."
Exterior rear: "Standing behind the tailpipes as it flies by."
Engine bay: "Hood open: intake roar, valvetrain and belts."
Onboard race: "Stripped race car with helmet-cam intensity."

Try each one in the free simulator, then keep the one that suits your speakers. For the spool and pssh of a turbo engine, see turbo and blow-off valve sound.

Listening position cards in the Sound Studio: Cabin selected, with Exterior rear, Engine bay and Onboard race beside it, and the sound stage below

In step and in tune

Plays well with the rest of your audio.

The details that make a synthesized engine work on a real car stereo.

Latency compensation

Automatic, so over Bluetooth the revs rise when the car pulls, not a beat later.

Music and engine together

Music balance and ducking for your playlist.

Mix presets

Stock, Sport, Race and Night (quiet), or your own, plus faders and a three-band equalizer.

Follows your car

It stops with the car audio and starts again when the same car reconnects.

Live output meter

Peak, RMS, limiter and a live spectrum of what goes to the speakers.

Phone speaker and headphones

No stereo? It also plays on the phone speaker or headphones, with a hearing-safety cap on headphone volume.

Sound Studio and sound stage are free
Live Drive: 3-day free trial on the yearly plan, then $2.99 a year, or $14.99 once
For the people inside the car: not a pedestrian warning system or a replacement for AVAS
Set the volume before you drive and keep it considerate

FAQ

Questions about car speakers

Can I play engine sound through my car speakers?

Yes. Connect your phone over Bluetooth, USB or a cable and WattGrowl plays through the car's speakers like any other audio, on any car stereo.

Is there a delay over Bluetooth?

Bluetooth adds a short delay, and WattGrowl compensates for it automatically, so the engine stays in step with your driving.

Can the exhaust come from the rear speakers?

On a surround head unit, yes: choose Car surround and turn up Steer exhaust to the rear. On a regular stereo, choose Car speakers and use Behind-you feel and Exhaust bass to subwoofer to place the exhaust behind you.

Can I play music and engine sound at the same time?

Yes. Play your playlist as usual; WattGrowl's music balance sets how loud the engine sits against the music, and ducking keeps the two together instead of fighting for the speakers.

What happens when I turn the car off?

In Live drive, the engine stops when the car audio disconnects and starts again when the same car reconnects.

Will people outside the car hear it?

About as much as they hear your stereo at that volume. The sound is for the people inside; it is not a pedestrian warning system and does not replace your car's AVAS.

Explore

Same speakers, a whole new engine.

Set up the sound stage for free in the simulator, then hear it on the road.