126 times extended dynamic range - what it means????

Question

Tell me, please, what is the meaning of the following sentence:"
This realizes a 126 times extended dynamic range which is equivalent to an outstanding dynamic range of 52dB."

I just cannot understand it!

Answer 1

The dynamic range is a ratio between between the smallest and largest possible values of a changeable quantity, which is usually the power of some signal: brightness, loudness, etc. It is frequently measured on a logarithmic scale in dB (decibel). For power, one bel = 10dB specifies a ratio of 10, 20dB specify a ratio of 100, 30dB specify a ratio of 1000, etc. Power grows as a square of amplitude with constant impedance, so ratio of 10 (10 times growth) in amplitude will correspond to 100 times growth of power =20dB. Ratio of 100 in amplitude is 40dB, ratio of 1000 is 60db, etc. Formally, dynamic range (in dB) = 20 log_10 (amp_max/amp_min) = 10 log_10 (power_max / power_min).

For example, consider an audio compact disk: the audio signal on a CD is 16-bit, which corresponds to a difference of 2^16 times in amplitudes or 2^32 times in power (loudness). 10 log_10 (2^32) = 20 log_10 (2^16) ~= 96.3 dB. However, the actual dynamic range of CD systems is usually lower due to lower dynamic range of the electronic components and speakers used.

Or a good LCD monitor has a contrast ratio (ratio of minimum brightness to maximim brightness) of 1:1000 = 30dB (brightness is power).

126 times extended dynamic range means that the ratio between the lowest and highest possible power values has grown 126 times, which means is has grown by 10 log_10 (126) ~= 21 dB. Supposedly the original dynamic range was 52-21=31(dB), which basically corresponds to 10^(31/10) = 1259 different values of power. Which are somewhat strange values: 52dB is supposedly too much for video, while 31dB is ridiculously little for audio. I hope my calculations are right.

Maybe you could clarify what kind of signal you're talking about?