Distortion doesn't just mean noise or hum or something objectionable. It simply means the speaker's output differs from the input. As stated above, many people prefer speakers that add bass, amplifiers that round off the top end or depress the midrange. Plus, any speaker's output in a real living space is likely going to be far off from what the manufacturer intended as rooms can reinforce or cancel bass, reflect or absorb highs, etc... That's why the only way to judge a speaker is to install it in your system and see if you like it.
