Rear speakers and subwoofers not working in Ubuntu 12.04 on HP dv6

Question

I have an HP DV6-6154tx laptop and i recently installed Ubuntu 12.04 with dual boot on it.

The Problem is only two of my speakers are working and the sub-woofers also are not working.

The result is extremely quiet sound from my laptop.

Please help.

Answer 1

I have the same laptop, I found a partial solution. With this solution the sub-woofers don't mute on headphone plug in.

open the file:

/etc/modprobe.d/alsa-base.conf

add the line:

options snd-hda-intel model=ref

If you find a better solution please let me know!