S

soft clipping: A form of clipping where the edges of the clipped waveform are rounded rather than sharp. Soft clipping is much easier on the ears and tweeters than hard, as it contains much less very high frequency energy. Compare with hard clipping.

soft knee compression: The output of a compressor whose gain reduction is brought in progressively over a range of input signal values, such as over 10db or so, starting a few dBs below the threshold. When the input signal amplitude comes within the range of the threshold, the compressor starts to apply again reduction, but with a very low ratio setting. As the input level increases, the compression is automatically increased until, at the threshold level, the ratio becomes infinite. Compare with hard knee compression.

Output Level, dB

	1:1 Ratio			1:1 Ratio
	2:1 Ratio	dB		2:1 Ratio
		Level,
	4:1 Ratio			4:1 Ratio
Threshold			Threshold	8:1 Ratio
		Output
	8:1 Ratio
	Hard limiting			Hard limiting

Input Level, dB	Input Level, dB
Hard-Knee Compression	Soft-Knee Compression

soft pedal: (1) On a piano, the pedal for producing a softer sound, accomplished by shifting the action sideways so that fewer strings per note are struck. On less expensive instruments, the hammers are simply moved closer to the strings. (2) A MIDI Controller Change message assigned to a parameter in a synthesizer which reproduces the function of a soft pedal.

Software Thru: When Software Thru is On, MIDI data at the sequencer’s MIDI input passes through to the output. When it is Off, MIDI data at the input does not appear at the output. See also MIDI Thru, Local Control.

Local Control On, Software Through On: Not recommended as this setting can cause note-doubling.

Local Control On, Software Thru Off: Recommended mode. The sequencer records data, and you hear what you play on the keys.

Local Control Off, Software Thru On: Alternate recommended mode. The keyboard acts like a master controller, but you’ll only hear what you play if Software Thru is On and directing the input signal to a specific channel, i.e., the one that feeds the sound you want to hear. Most sequencers let you choose whether Thru echoes data on the incoming channel or directs this data to a different channel.

Local Control Off, Software Thru Off: Not recommended. This allows the playback of tracks already recorded into the sequencer, but it is not possible to monitor what is being played or recorded.

solid-state: A term which indicates that a device uses semiconductor (IC) devices, instead of vacuum tubes. Note that tubes in the UK are called valves.