I see a lot of people have issues with beatsaudio on hp laptops, and they solve them partially/totally editing the
/etc/modprobe.d/alsa-base.conf file. However, none of those fixes have worked for me (A guy suggested them to me in the irc chat also).
The problem is that this laptop has two speakers in front, two down the screen and a small subwoofer down the case. The problem is that the two front speakers and the subwoofer don't work at all, thus causing my music and any other sounds bassless (And being a big electronic music fan, I can tell you that's awful).
I dual boot with win8 and I had the same issue there, but quickly fixed it installing the IDT High Definition codec driver from the HP support center, which is seemingly not available for linux at all. The strange thing is that it doesn't seem to be a driver issue, since if I plug some quality headphones, the bass is there, so the audio codec/soundcard is processing all the sound properly, it is just not sending it through the appropiate channels.
In case it is useful, my laptop specs: http://www.cnet.com/laptops/hp-pavilion-dv7-6165us/4505-3121_7-34800415.html