2 – Introducing the TASCAM
About the technology
The models employed by the
Another advantage of this
Finally, the quality and
So what exactly does it do?
While there is a lot of fairly complicated stuff going on under the hood, the essential functionality of the
Understanding Compression
By using a compressor to decrease the dynamic range of the vocal, the softer sounds are increased in loudness and the loudest sounds are reduced in loudness, tending to even out the overall level of the track. The overall level of the compressed track can then be increased (using what is referred to as
Threshold and Ratio
How is compression measured? What is a little compression and what is a lot of compression?
The effect a compressor has on a track is determined by the settings of its threshold and ratio. The threshold is the level above which the signal is attenuated. The ratio is the measure of how much the dynamic range is compressed.
The graph shown below shows the relationship between the input level of a signal and the output level of the signal after compression. Notice that signals that are louder than the threshold are compressed (reduced
in level) while those softer than the threshold are unchanged.
As the input signal exceeds the threshold, gain reduction (reduction in loudness) is applied. The amount of gain reduction that is applied depends on the compression ratio. The higher the compression ratio, the more gain reduction is applied to the signal.
The graph shows the relationship between compression ratio and gain reduction. Examine the 2 to 1 ratio curve. For signals above the threshold, this setting transforms a range of loudness 2 units large into a range of loudness one unit large (i.e., if the input signal gets “x” units louder, the compressed signal increases by only “x/2” units).
Compression is probably the most widely used (and potentially confusing) signal process used in today’s studios. Simply put, compression reduces the dynamic range of a signal. That is, it reduces the difference in loudness between the loudest and quietest parts of a piece of music. Another way to think about this is that the compressor is acting as an automatic fader which fades down when the signal gets loud and fades back up when the signal gets soft.
LOUDER
THRESHOLD
1 TO 1 RATIO
2 TO 1 RATIO
4 TO 1 RATIO
8 TO 1 RATIO
99 TO 1 RATIO
Why reduce the dynamic range? Consider the problem of mixing the vocal in a contemporary rock or pop song. Typically, pop music has a relatively consistent level of loudness. If an uncompressed vocal track is added to a typical pop mix, loudly sung words or syllables would jump out of the mix, while quieter phrases would be buried beneath the instrumental texture. This is because the difference between the loudest and softest sounds in the vocal - its dynamic range - is very large. This same problem occurs for any instrument which has a dynamic range larger than the music bed into which it is being mixed. (For that reason, most instruments, not just vocals, undergo some compression in the typical mix.)
OUTPUT |
| I/O CURVE |
LEVEL |
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|
LOUDER
INPUT LEVEL
10 TASCAM