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Digital Signal Processor (DSP)
A digital signal processor is form of microprocessor with an optimized
architecture required for the very fast mathematical processes used in digital
signal processing.
The tremendous mathematical processing power available allows for much
greater accuracy in the computed results than any other method.
Most modern Castle instruments implement the use of digital signal processors.
Doppler Effect
This is the apparent change of frequency of a sound wave due to relative motion
between the source of the sound wave and the observer.
Imagine an observer is located on a Formula 1 race track and an F1 car
approaches the observer at a constant speed and so the frequency the car
produces is the same.
The observer hears the car approaching but as the car approaches it is getting
nearer to the source and as such the sound waves apparent frequency gets
higher which is noticed by a higher pitch sound from the car.
When the car passes by the observer this effect is reversed, hence the sound
wave frequency decreases which is results in a lower pitch sound from the car.
Dose
See ‘Noise Dose’.
Dynamic Range
This is the total range of signal levels that an instrument can utilize between the
upper and lower operating boundaries.
Lower operating boundaries are generally governed by electrical noise, whereas
the upper operating boundary is generally governed by non-linearity due to signal
clipping.
See also ‘Noise Floor’, ‘Under Range’ and ‘Overload’.
