What do the common audio effects and processors do and what are their key controls?
Audio effects and processors: reverb, delay (echo), chorus, flanger, distortion, equalisation (EQ) and compression, what each does to the sound and their key controls.
An SQA National 5 Music Technology answer on the common audio effects and processors: reverb, delay (echo), chorus, flanger, distortion, equalisation and compression, explaining what each does to the sound and the key controls a candidate must recognise.
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What this concept area is asking
The SQA wants you to know the common audio effects and processors, what each does to the sound, and at least one control on each. In the question paper you hear effects on excerpts and answer scenario questions; in the practical work you apply these effects yourself, so recognising and explaining them is essential.
Time-based effects: reverb and delay
These two are easy to confuse because both add a sense of space. The clue is whether you hear distinct, separate repeats (that is delay/echo) or a smooth wash of reflections that fills the space (that is reverb). Both are used heavily on vocals and instruments to add depth.
Modulation effects: chorus and flanger
Chorus is the gentler of the two: it broadens a guitar or vocal so it feels fuller. A flanger is more dramatic, producing the unmistakable sweeping whoosh you hear on some guitar and synth parts. In a listening question, a thicker "many voices" sound points to chorus, while a swirling jet-like sweep points to flanger.
Distortion and equalisation
Distortion changes the character of a sound (used creatively for rock guitar), while EQ shapes the frequency balance of a sound (used both creatively and correctively in a mix). EQ is one of the most-used tools in mixing because it lets every track sit clearly without masking the others.
Dynamics processing: compression
Compression is the processor candidates most often need to name when a recording is uneven - a vocal that jumps between loud and quiet, or a bass that is inconsistent. By taming the peaks, it makes a part sit steadily in the mix. Knowing threshold and ratio as its two headline controls is the reliable mark.
How this concept area is examined
Questions ask you to describe what an effect or processor does, name a control on it, or choose the right one to fix a described problem (an echoey hall sound, an uneven vocal, a dull tone). The reliable marks come from knowing each effect's job and at least one real control, and from telling apart the easily confused pairs - reverb and delay, chorus and flanger, EQ and compression.
For the official course specification
The SQA publishes the full National 5 Music Technology course specification, specimen and past question papers and the assignment task at sqa.org.uk. Always revise from the current specification and SQA past papers, because the terminology and question style are board-specific.
Exam-style practice questions
Practice questions written in the style of SQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
SQA N5 style4 marksDescribe what reverb and delay each do to a sound, and state one control found on each effect.Show worked answer →
Two marks per effect: one for what it does and one for a control.
Reverb adds the sense of space and natural echo to a sound, as if it were played in a room or hall; it makes a dry sound feel "wet". A control on reverb is the decay (or reverb time), which sets how long the reverberation lasts (room size and mix/wet-dry level are also accepted).
Delay (echo) repeats the sound one or more times after the original, creating distinct echoes. A control on delay is the delay time (how long after the original each repeat sounds); feedback (number of repeats) is also accepted.
Markers reward "space/echo" for reverb with a control such as decay or room size, and "repeats/echoes" for delay with a control such as delay time or feedback.
SQA N5 style3 marksA vocal recording is uneven, with loud and quiet parts. Name a processor that would even it out, explain what it does, and name one of its controls.Show worked answer →
One mark for the processor, one for what it does, one for a control.
The processor is a compressor. Compression reduces the difference between the loudest and quietest parts by turning down (attenuating) signals above a set level, making the overall level more even and controlled.
A control on a compressor is the threshold (the level above which compression starts); ratio, attack and release are also accepted.
Markers reward "compressor/compression", an explanation about reducing the dynamic range or evening out loud and quiet parts, and any genuine control such as threshold, ratio, attack or release.
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