Three factors will make a great sound system sound great or bad: price, components, and installation. Cheap connector wires such as speaker wire, RCA cables, and power wire might save you money, but make these high-end components sound bad. The low-cost stuff will get you low-cost sound! However, you can buy installation parts and components that will greatly enhance sound quality and not break the bank. Crutchfield is a great source for everything one needs to install a stereo properly, including good information.