Music Technology - Coursework Example

+4dBu is generally found in professional level equipment such as public address systems. Finally, -85dBu indicates the level of noise floor (residual electronic noise) in the sound amplifying system. Noise floor is the measure of the lowest audible sound that can be amplified by the system. Collectively, the three levels are known as the operating line levels of an audio system (Glenn, 1998, p.731). A.2. What do the ranges of 24 dB, 89 dB and 109 dB indicate? Explain the function that each of these ranges has in an audio system? (9 marks) The range 24dB in the diagram indicates the headroom of the sound system (peak level- nominal level) = +28dBu-(+4dBu) =24dBu.

According to Rossing (2002, p.168), the main function of this range is to describe the capacity of the sound amplifying system to handle loud sound peaks. For example, a sound system with a larger headroom range is often able to handle significantly louder sound peaks before the sound is distorted or broken. On the other hand, 89 dB range shown in the diagram indicates the S/N ratio (Signal to Noise ratio) of the sound amplifying system. Generally, S/N ratio refers to the difference between the nominal level of the sound system and the noise floor.

When the S/N ratio is combined with the headroom, the result is known as the dynamic range assuming that there is no signal below the noise floor in the sound amplifying system (Borwick, 1980, p.45). . gard, the dynamic range of the system function as the indicator of the difference between the electro-acoustic noise floor and the peak output level of the audio system. B. Why does the graphic refer to two different kinds of dB? Explain both types extensively using formulas for both types too. (15marks).

The graphic diagram refers to the two types of dB namely the dB (SPL) and dBu scales. With regard to the dB (SPL), the primary variable measured is the sound pressure level in the audio system. This kind of dB is achieved by measuring the ratio amplified input signals using the logarithmic formula: 10 log (P2/P1) dB   where the log is assumed to base 10. (Rossing , Moore , Wheeler, 2002, p.87). The other type of dB used in the diagram is dBu which generally indicates the output of the sound amplifying system (amplitude ratios).

dBu is the unit measure of the absolute value of the electrical potential of the system in volts (relative to the sound produced). The formula for this kind of dB is: 20 log10 (V/ V0) = 20 log10 (V/ 0.7746), where voltage is measured using root mean square (Glenn, 1998, p.851). ` C. About the values showed above, would you considered this to be a professional system or only a home-made-like system (e.g. cassette or vinyl) based)? Explain your choice. (5marks). According to the values given in the diagram, the system illustrated is most likely to be a professional system.

For example, headroom of 24dB is capable of ensuring high fidelity sound that is only found in the professional sound amplification systems which are often comparatively more sophisticated than the normal homemade systems like those using vinyl and cassettes. Additionally, the large dynamic range indicated in the diagram is a likely suggestion that the system has a high