xfce4-mixer
Lubuntu shares many components with XFCE. My suggestion would be to use the XFCE4-Mixer. This still gives you a lightweight solution compatible with the lxde ethos.
to install
sudo apt-get install xfce4-mixer gstreamer0.10-alsa
This installs the following limited number of xfce packages -
exo-utils libgarcon-1-0 libgarcon-common libwnck-common libwnck22 libxres1
xfce4-mixer xfce4-panel
to run
type xfce4-mixer
in a lxterminal
In Options Auto-Mute Mode
It should be set as Disabled.
pavucontrol
Slightly more heavyweight - you could install pulseaudio and thus use the pulseaudio packages such as pavucontrol
to install
sudo apt-get install pulseaudio pavucontrol
This installs the following pulseaudio packages:
gstreamer0.10-pulseaudio libasound2-plugins libspeexdsp1
pulseaudio-esound-compat pulseaudio-module-x11 pulseaudio-utils rtkit
to run
type pavucontrol
in a lxterminal
Install QT4 COnfiguration.
sudo apt-get install qt4-qtconfig
Then Select GTk+ in GUI Style
Best Answer
setxkbmap -option "compose:caps"
for CapsLocksetxkbmap -option "compose:ralt"
for right alt =)