The higher quality of music is not simply due to the higher sampling frequency, but rather a combination of various causes. Most people can only listen to up to 18kHz, with the frequency bandwidth of the CD up to 20kHz completely meeting the needs of the listeners. However, after this I will introduce 3 elements that degrade the quality of music that can be solved using bit-rates and higher sampling frequencies.
- The CD standard for 16 Bit resolution is equivalent to 65,536 different signal hiccups to digitize analog audio signals. This limit causes distortion that can be heard in the silent parts of the song. These quantized noises are always present and can even be compared to the noise present on mortars or coal plates. However, because this is an electronic noise, it will be more difficult to hear than the noise on tape and coal disc.
- The conversion between analog and digital signals is still incomplete one hundred percent accurate. For example, the low-pass filters used in the analogue-to-digital ADC and digital-to-analogue DAC converter devices cannot guarantee theoretical conversion perfection. In addition, jitter noise of the clock signal also makes the conversion inaccurate and adds distortion to the output signal.
- Digital recording requires extremely high accuracy and avoids inter-sample peaks ISP (peaks between different recording samples). At the same time, digital recording also requires the sound engineer's technique to adjust the maximum gain carefully to achieve full range of dynamic range.
2 / Using high quality native Studio Master recording can help reduce the problems of the usual CD recording quality mentioned above.
- Modern audio devices can reproduce a dynamic range of up to about 120 dB by using audio signals with bit-rates as high as 24Bit. At this time, quantum noise levels can be ignored because the digital signal level will be 16,777,216 farther than the 65,536 level of 16-bit music quality.
- Higher sampling frequencies allow the recording of music signals above the 20 kHz frequency threshold, enabling recordings to reproduce the entire synthesizer of the recorded instrument. At the same time, higher sampling frequency also reduces inter-sample peak phenomenon, reducing audible distortion.
- The combination of high bitrate and higher sampling frequency enables sound engineers to have enough bandwidth and capacity to create high quality recordings and audiophiles that can reproduce sound. true, close to the original recording
There is a certain correlation between bitrate and sampling frequency. If you increase the sampling frequency, it will lead to an increase in the Signal to Noise ratio or also called Signal to Noise Ratio (SNR). If you want to keep the SNR level stable, it will also lead to a reduction in the number of bits of the digital signal. The DSD (Direct Stream Digital) music format is a good example of this when the digital signal level has only 1 bit used but has a very high sampling frequency up to 5.6448 MHz for DSD128 format.
Here is the MusicScope software – Software that measures many different music file formats to differentiate differences through charts and images
The image below shows that a single music file recorded CD-Record (16 Bit / 44.1kHz) with a limit of more than 20kHz can be seen through the spectrum spectrum table and waterfall chart (waterfall diagram) . More specifically, the recording shows some inter-sample peak errors (in the History section), leading to an increase in the maximum peak level of more than 3dB (in True Peak Level).
Here is the same recording but in MP3 quality (128 kBit / s) that was converted to WAV format. Lossy music files like MP3 and AAC are used to compress music files through a lossy quality lossy compression algorithm. In the picture below we can see that the maximum frequency level is only up to 16.5 kHz as well as the amount of information at high frequencies is greatly reduced through the waterfall diagram. Compression is performed by omitting information in high frequencies that are done through a model based on human sound perception research when lost frequency information is covered by the available parts. Great volume in the song.
If you compare the MP3 recording compared to the original studio recording (Native Studio Master) in the picture below, you will see a very clear difference.
This image analyzes the original studio recording with bitrate quality up to 24 bits and sampling frequency up to 96kHz. High quality music files can be saved in FLAC or ALAC formats to save storage space instead of the usual WAV and AIFF file formats. The recording shows that the perfect collection threshold does not suffer from inter-sample peaks. The frequency range is up to 40kHz and it is possible to reproduce the whole harmony of the collected instruments
Finally, a recording in DSD128 (Direct Stream Digital) in DSD128 standard with sampling frequency up to 5,6448 MHz. The frequency of music can be seen up to 48 kHz. You may still have signals at higher frequencies, but most of these signals are noise that is pushed up to very high frequencies. This both increases the accuracy of audible music signals, and the ears of listeners cannot sense these frequencies, nor are there any such high-frequency instruments.
Measuring devices and software are provided by XiVero team (http: /www.xivero.com). They developed MusicScope software to be able to measure music files accurately.
4 / Saying that human ears can distinguish the difference between different formats?
This depends very much on the quality of the original recording, if the original recording is of poor quality with low dynamic range and there are many distortions or distortions, even if used in 24-bit or DSD format It doesn't improve. With good quality recordings and careful investment, the difference is more easily recognizable.
In addition, you also need to invest in a sound system with high detail, transparency to be able to fully hear the contents of the recording. You should not be too important on devices with High-res Audio stamps or not, because High-Res Audio stamps on audio devices are not too important, most are just a means used in marketing. main. Instead, find and hear which device has the most detailed sound quality and best fit for you.