Before doing any digital signal processing, we need to digitize the analog signals to 0's and 1's using Analog to Digital Converters (ADC) and vice versa with Digital to Analog converter (DAC) at the ouput ends. Two very important product design choices then come to play:
* The sampling frequency, i.e. how often do we want the ADC to take a reading of the analog signal, and turn it into a digital signal? A simple rule of thumb says: whatever signal we want to digitize, sampling frequency should be at least twice the maximum frequency of the signal (this is also called Nyquist-Shannon theorem). With the human-ear audible spectrum ranging from 20Hz to 20 kHz, the sampling frequency should at least be above 40 kHz. While CD players use 44.1 kHz and DVD use 192kHz, most professional audio products are standardized to 48kHz and 96kHz.
* The bit resolution (also called bit depth) is the second important concept to pay attention to. It basically dictates the number of bits used to represent each sample. Larger the resolution translates to better dynamic range and signal to noise ratio (SNR) performance of the product. That's because the converters will be able to better represent very small fluctuations of the audio signal. Once again a simple formula helps us calculate the minimum bit depth required to achieve a specified dynamic range:
DR = 1.76 + 6.02* Bit depth
e.g. CD players typically use 16 bit depth. Therefore, the maximum achievable dynamic range of the system, no matter how good the DAC is, would be: 1.76 + 6.02*16 or about 98dB. To achieve better dynamic range, DVD, Blue Ray players and most professional audio products use 24 bit depth.
Note that ultimately this formula yields results at 24 bits that cannot be achieved in the real world due to the IC limitation of about a maximum of 120dB dynamic range.
To summarize, sampling rate and bit depth of audio converters both matter when trying to achieve higher dynamic range for better quality audio. To make sure you get the best digital audio quality out of our platforms, all our products are standardized to 24bit, 48/96kHz converters. Wait till you hear the difference!