i take it you want some sort of high quality "audio system" that can hook up to your computer. if that is the case we need to know a few things. if your question is how to boost the sound using integrated speakers found on laptops...you are out of luck as they are not very powerful.
-pc speakers? home theater speakers?
-2.1, 5.1, 7.1, other?
-what you plan to use the system for
-plans for connection cable.. ie via hdmi, optical out, other?
also i need to know how best to have an outdoor sound,as in all the equipments needed to have a quality outdoor sound such as a mixing console, a graphic equalizer, a sound booster a power amplifier an effect machine and more importantly how to set it up perfectly