How to disable internal Loudspeaker
My Compaq Evo has two internal speakers, the PC speaker (the one responsible for beeps, etc) and another conventional loudspeaker connected internally to the sound board. One would expect that conecting the headphones to the headphones jack will automatically shut off/disable the internal speaker but it doesn’t. You must first go to the Volume Control at System -> Preferences -> Volume Control and then click Edit->Preferences and enable the Headphone Jack Sense checkbox. I wonder why it is not enabled by default.