Ringing

There’s a kind of distortion in digital audio that happens before the music even starts.

That’s not a philosophical statement—it’s pre-ringing, the unnatural "echo" that appears before a transient when a certain type of digital filter is used. You hit a drum, and mathematically, the sound appears a split second before the hit.

It’s not loud, but it’s wrong.

This is a side effect of linear phase filters, which are mathematically perfect in frequency domain but ignore the time domain entirely. They preserve amplitude response but smear time. Engineers love them for their precision—but listeners often find them lifeless, because pre-ringing messes with the natural envelope of sounds.

Minimum phase filters, on the other hand, sacrifice some symmetry to get rid of pre-ringing. You’ll still get ringing, but it comes after the transient, where your brain is more likely to accept it as reverb or decay.

The takeaway? Not all digital filters are created equal. The way a DAC handles time affects whether the music feels alive or artificial. You might not hear the pre-ringing as a separate sound—but you will hear its effect as a lack of presence and impact.

Perfect math doesn’t always make perfect music.