Linear The simplest of fade curves is the linear curve and it is normally the default fade. It takes a straight line and introduces a curve. This curve represents an equal degree by which the gain increases or decreases during the length of the fade. A linear fade-in curve makes it sound as though the volume increases sharply at the beginning, and more gradually towards the end. The same principle applies on a fade-out where a gradual drop in volume can be perceived in the beginning, and the fade gets more abrupt towards the end. If in your audio there is a natural ambience or reverb present that one would like to reduce, the linear shape would be ideal because of the initial drop in perceived volume. When applied it shortens the ambience. Also if the music requires an accelerating effect, this linear curve can also be applied. This type of fade is not very natural sounding. The principle of a linear crossfade is: at the beginning of the fade the perceived volume drops more quickly, one can see at the halfway point (in the middle of the crossfade) that the perceived volume drops below 50%. This is a very noticeable drop in volume. Also if the control can move from position 0 to 100, and the percentage of the signal that is allowed to pass equals the position of the control (i.e. 25% of the signal is allowed to pass when the control is 25% of the physical distance from the 0 point to the 100 point). At the midpoint of the fade the effect of a linear crossfade is that both the sounds are below half of their maximum perceived volume; and as a result the sum of the two fades will be below the maximum level of either. This is not applicable when the two sounds are on different levels and the crossfade time is long enough. In turn if the crossfade is short (for example on a single note) the dip of the volume in the middle of the crossfade can be quite noticeable. Logarithmic Another type of curve is called the logarithmic ratio (also known as "audio taper"), or an inverse-logarithmic ratio. The log/audio-taper more closely matches human hearing, with finer control at lower levels, increasing dramatically past the 50% point. Importantly, the perceived volume of a sound has a logarithmic relationship with its level