Question

1. Delay is used to create a variety of perceptions. Describe two of these perceived effects.

2. What type of delay would you use to create a series of uneven delays? Explain.

3. What is the difference between reverb and delay?

4. What is a comb filter and what does it have to do with effects/processing?

5. What problems(s) might you expect if you had two microphones in front of a guitar amp: The first mic is positioned 1 foot away, the second 2 feet away? Explain.

Answer 1

2) flanger. Using a delay line creates an unlimited series of equally spaced notches and peaks. It is possible to cascade a delay line with another type of all-pass filterThis combines the unlimited number of notches from the flanger with the uneven spacing of the phaser.

3)

Reverb:
Ambient effect added to your guitar tone to give the feel and tone of playing in a type of "room".
Great for fixin' up a dry signals and giving more ambiance thats pleasing to hear.
For example, room, hall, concert hall, church, ect...

Delay:
Essentially adds an echo effect to your guitar tone that can bet set to different types, tempo settings and repeats.
Great for adding size to your tone or just a "cool" effect to with limitless options.
Many kinds of echo such as, digital, analog, tape, revese, modulation, ect...

4)The deal here is the studio needs to be a room that is at least around 12 feet in at least one dimension (and bigger is better to a point). As we know, sound travels at approximately a millisecond per foot. If you're using a room that is 12 feet long, and if the guitar amp speaker was at one end and the room mic on the other end, that is about a 10 foot spread. So this equals around a 10-millisecond delay. You would think the comb-filtering effect is in play since it takes around 30 milliseconds to notice a distinct delay (as in, to get out of comb filtering land and into the range of distinct delays, which occurs at approximately 30 milliseconds). Technically, you should have comb filtering in this case, but the odds are good it will not be noticeable in a room that is at least slightly open sounding, since the tone totally changes compared to the close mic for a few reasons. The room mic waveform becomes defused due to air movement in the room as well as room reflections coming into play. The reflections bouncing around will arrive at many different delay times and the later the reflection, the darker the sound.

Note that if you are hearing some comb filtering cancellation in a small room between the close mic and room mic, you can always delay the room mic using a delay line. So lets use 30 milliseconds for the math base a guitar amp that is room-miked 10 feet away will have a natural delay of 10 milliseconds, and may require a delay of 20 milliseconds. Experiment as usual looking for a great sound.