I have a old HP Pavilion dv6645eo with the HP Quicklaunch buttons. When I use the volume buttons, the only sound in the upper echelons of the 'sound bar'.
I've been looking long after why it happens. But by opening
alsamixer in the terminal, I found out why.
The volume scale covers BOTH headphones and master on the same scale! When headphones are at max, then it adjust volume on the master - that's why there is only sound on the top steps.
How do I get the voice buttons to ONLY adjust the master?