system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If I had one speaker with say 50 decibels coming out, then turned on another of the same. How loud is it?
gpt
Adding a second speaker should double the out power, which increases the sound pressure by 1.4 times, which should sound 23% louder, which is a increase of 3dB.

That assumes there is no destructive interference between the two speakers which could make things sound even quieter.