Large amounts of damping of the loudspeaker is not necessarily better, for example a mere 0.35 dB difference in real-life results between a high (100) and medium (20) Damping Factor. Some engineers, including Nelson Pass claim loudspeakers can sound "better" with lower electrical damping. A lower damping factor helps to enhance the bass response of the loudspeaker by several decibels (where the impedance of the speaker would be at its maximum), which is useful if only a single speaker is used for the entire audio range. Therefore, some amplifiers, in particular vintage amplifiers from the 1950s, '60s and '70s, feature controls for varying the damping factor. While such bass "enhancement" may be pleasing to some enthusiasts, it nonetheless represents a distortion of the input signal.