Speakers should be played at mid-level volume to prevent distortion and possible speaker damage.
Speakers are the ultimate deciding factor in sound quality. A top of the line system will still sound bad on poor speakers, and vice versa.
The length of the speaker cable needed to connect your speakers does NOT need to be the same for each speaker. Distortion would not take place until the cable length got over 500 feet.
A speaker is actually an electro-acoustic transducer that has the ability to change electrical signals into sounds.
