A delay essentially creates an echo, although you can often use delays to create more complex time-based effects. The source signal is delayed so that it is heard later than it actually occurred.

Common Delay Parameters

Below are some of the most common reverb parameters for the delay effects:

• Time. This is the time (in milliseconds) between the source signal and its echo. The simplest delay effect is a single repeat. A short delay between 30 and 100 ms can be used to create slap-back echo, while longer delay times produce a more distant echo. Delay times that are too short to hear as distinct echoes can be used to create thickening effects. Whether these echoes are timed with the tempo is a matter of stylistic choice. This is the parameter that is controlled by the Tap Tempo button. Using the Tap button on the PreSonus^® StudioLive^® mixer, you can speed up or slow down these repeats or, more commonly, time the repeats to occur with the tempo of the music.
• Time X. Time X is the value of the beat you are using as a reference for the tempo. The basic unit of measure is a quarter note, so for example, if the beats you are tapping represent quarter notes in the music, you would set Time X to 1.00. If they are eighth notes, you would set Time X to 0.50; half notes would be 2.00; and so on. In this way, you can precisely synchronize or syncopate the delay echoes to the music in real time.
• Variable Feedback. Variable feedback, or regeneration, produces multiple decaying repeats. Increasing the feedback value increases the number of echoes, as well as the resonance that is created as one echo disappears into another.
• F_Frequency. Sets the center frequency in Hz for the Filter Delay.
• F_Gain. Sets the boost at the center frequency for the Filter Delay.
• F_Q. Sets the Q for the Filter Delay. The Q is the ratio of the center frequency to the bandwidth. When the center frequency is constant, the bandwidth is inversely proportional to the Q, so as you raise the Q, you narrow the bandwidth.