We all agree zero means nothing, right?
Have you ever noticed that in audio, we use zero as something?
In a volume control or on a VU meter, 0dB means the loudest you want to get—a bit contradictory, no?
In audio, 0dB actually represents full signal—the maximum level a system can handle before distortion. It's a reference point, not an absolute value. Engineers use decibels (dB) to measure sound levels relative to this reference, so when you see 0dB, it means you're getting everything the system can deliver cleanly. Anything below zero on your volume control or meter shows how much the signal is being reduced from that full output level.
Historically, engineers set 0dB as the "full level" based on something called unity gain—a point where the system is working efficiently, without adding or reducing anything (which is where the zero comes from. It's not amplifying).
Think of 0dB as the top of the hill: everything below it is a reduction. That’s why all volume controls work in the negative—because you’re starting at full capacity (zero) and moving down.
So yeah, in audio, zero actually means something!
