Every so often a stereo produces a sound so convincing that I have the ridiculous urge to reach out and touch it.

Not the loudspeaker. The sound.

Yes, I know. This is why normal people worry about me.

But that almost-touchable quality—palpability—is one of the things we all work hardest to preserve when voicing a product. The challenge is explaining to an engineer how to design for something that sounds more like sorcery than a specification.

For me, it begins with bass.

Clear away the filters and phase shifts that rob bass of its timing and suddenly the kick drum doesn’t merely make a low-frequency noise. It connects with your gut.

That physical thump was my first experience of reproduced sound becoming palpable.

With time, we learn to recognize subtler versions of the same illusion. A bell rings with such truth that the room seems to contain metal. A voice arrives with the tiny inflections and spatial cues that convince us another human being is standing between the speakers.

We know the performer isn’t there.

And yet, for a moment, the body leans forward before the intellect catches up.

Measurements can tell us a great deal about a component.

But the magic begins when the stereo makes us forget we’re listening to one.