This week I’ll give a quick explanation to the three effects categories of DSP (Digital Signal Processing) and they are, dynamic, delay, and filter effects. These three categories are generally related to three of the principles of sound, amplitude, propagation, and timbre.
- Compressor – Narrows a signal’s dynamic range. Amplifies low sounds and a attenuates loud sounds. Making the audio have a more normalized feel.
- Limiter – Keeps the audio level from going over a pre-set amount.
- Expander – Decreases the level of signals that fall below a certain threshold to a specified range. For instance, if the threshold is set to -6dB, once the audio is below that threshold, the audio can be pushed down to -10dB, but not complete silence.
- Noise Gate – Decreases the level of signals that fall below a certain threshold to complete silence.
Dynamic effects automatically control amplitude over time.
- Reverbs – Reflections of sound within a space that slowly decay
- Delays – Recorded sound that is either played back multiple times or fed back into the recording to create a repeating decay.
- Phasers – Audio that is split into two separate paths. One path is an all pass filter which preserves amplitude. When the two paths are mixed there is cancellation of notched frequencies creating a phasing effect.
- Flangers – The same as a phaser, although the all pass filter is replaced by a delay.
- Choruses – Two sounds that are almost similar in timbre and pitch converge and are perceived as one.
Delay effects are related to propagation sound. They can create the illusion
of three dimensionality. They can also make the audio sound like it was recorded in either a small or large room.
- High Pass Filter – Allows all frequencies above the cut off point to pass. HPF cuts the lows and allows the highs to pass.
- Low Pass Filter – Allows all frequencies below the cut off point to pass. LPF cuts the highs and allows the lows to pass.
- Band Pass Filter – Allows a specified band of frequencies to pass. All other frequencies above and below the specified band are then cut.
- Parametric EQ – A more precise eq that controls three parameters, amplitude, center frequency, and bandwidth.
- Graphic EQ – An equalizer with pre-set bands that can be boosted or cut in a range of -/+ 6dB to -/+12dB.
Filter effects control the timbre of sound.
If you have any corrections, please feel free to comment.