What is a good loudspeaker supposed to do?
A loudspeaker takes the place in the room of what it is reproducing, be it a piano, a vocalist, an orchestra, or a spectacular sound effect. To be good, it must accurately reproduce in time, in phase, and in amplitude, the signal passed on to it from the amplifier. It should have low distortion, but it should not focus on reducing one type of distortion at the expense of others. Similarly, it should be a balanced design with attention paid to time, phase, and amplitude. It should be built of high-quality components that reveal the most musical truth in live vs. reproduced tests. The components should be engineered for maximum reliability and consistency. It should be full-range. Bass is the foundation of music and conveys much of the emotion. Without bass, there is no music.
