Lexicon Level
In audio engineering or electroacoustics, the term level refers to the strength of a signal. A higher level corresponds to a stronger signal. It depends on the type of signal how the level is measured and in which unit it is expressed.
Examples:
- The sound level is the strength of an acoustic signal, and is thus related to the sound pressure, a mechanical quantity.
Signal level is usually the level of an electrical signal in a device, in most cases a voltage signal. An audible sound is electrically represented by this voltage signal. The signal level is usually expressed as a dB value or as an effective voltage (in volts), sometimes also as power (in watts).
- Digital level is the level of a digitally represented audio signal. It is usually expressed as dBFS.
When a signal is converted from one representation to another, it is specified which level of one representation corresponds to which level of the other representation. This happens, for example, in the speaker, which converts an electrical signal into an acoustic signal. Here, the effectiveness indicates which sound level is caused by which electrical signal level (e.g. 1W == 92dB(SPL) at 1m distance in free field). With a D/A Converter there is a similar problem: Here it is stated which level of the digital signal corresponds to which level of the generated analog signal (e.g. 0dBFS = 18dBu).
In leveling, a sound system is adjusted so that a test signal of known strength fed through the system produces a desired reference level (sometimes specified by standards) at every point. This achieves a high quality audio signal in the system by making the best use of the characteristics of the equipment. It is necessary to make a compromise between the Fremdspannungsabstand and the Aussteuerungsreserve.
See also the Wikipedia articles: [level (physics)], [sound level], [reference level]