Apple TV volume issues when Airplay - music too loud and video too quiet

When I am using Airplay to send music and videos from my iPhone or MacBook to my Apple TV, there are drastically different volume levels which is rather inconvenient.

Apple TV is connected to a stereo and then a projector via HDMI

When playing video through screen mirroring, I have the volume on my MacBook and in the Video Player app or browser set at maximum and I still need to manually increase the volume knob on my stereo, whereas when I airplay music from either device, I have to turn the volume to one notch above "mute" and still sometimes the music is so loud I need to walk across the room and manually turn the knob down. This is annoying having to adjust for video and audio every time I switch back and forth. Why the inconsistency? Airplay = Airplay, no?