Laptop speakers are often insufficient, and external speakers with hardware amplification are sometimes unavailable.
Volume settings are maxed out:
mixerctl: outputs.master=255,255
sndioctl: output.level=1.000
cmixer all 100%
E.g. sox or mpv have --volume option which lets you set over 100% volume. But browsers/messengers/others often lack such an option, and even if all apps had it, one would prefer to set it system-wide.
Is there such a way for OpenBSD?
People on the Internet warn you can damage your speakers with overly loud playback. Operator's discretion advised.