Why volume boosters distort — and how to boost cleanly

Digital audio has a ceiling. Any sample louder than that ceiling can't be played, so something has to happen to it. What a booster does at that moment decides whether it sounds clean or crackly.

Clipping: why boosters crackle

The simplest booster multiplies the sound and lets the peaks hit the ceiling. The tops of the waveform get chopped flat — that's clipping. It adds harsh, buzzy overtones you hear as crackling or fuzz. At 600%, a normal music video can have a third of its samples clipped. Some systems soften this with their own safety limiter, but the booster itself isn't protecting the sound.

Soft clipping: better, but still fuzz

A soft clipper rounds the peaks off instead of chopping them. It's less harsh, but it's still changing the shape of the wave — so it still adds distortion, just a smoother kind.

Limiting: loud and clean

A look-ahead limiter works on volume, not shape. It sees a peak coming a few milliseconds early and lowers the volume smoothly just enough for it to fit, then brings the volume back. The waveform keeps its shape, so no distortion is added.

The catch: done badly, a limiter either sounds quiet (it turns everything down) or “pumps” and follows bass notes, which causes its own fuzz. Timing is everything.

How SoundBooster does it

The SoundBooster Chrome extension uses a stereo-linked look-ahead limiter with a 6 ms look-ahead and a fast release, tuned to be as loud as possible before it starts to follow bass waves. In our tests at 600%, it adds no measurable harmonic distortion, while simple boosting clips about 30% of the samples. At 100% the limiter does nothing at all, so normal listening is untouched.

It's on by default. You can switch it off in Advanced controls if you prefer raw, unprocessed boosting.

Tips for the cleanest boost

• Boost only as much as you need — 150–300% fixes most quiet audio.
• Leave bass boost modest at high levels; bass uses up the most headroom.
• If voices sound harsh, lower the treble or use the Quiet dialogue profile.