In recent years, the hot spot in the audio circle is Bluetooth wireless, but there are also many friends who toss traditional PC HiFi. However, compared with the emerging wireless audio market, the traditional PC HiFi circle that has developed for many years is even more immature, and metaphysical theology is emerging in an endless stream. Some manufacturers even use this to harvest the IQ tax and launch so-called "HiFi products" that are inexplicable in principle - for example, recently, I have encountered manufacturers promoting so-called "HiFi-level" SSDs. Why is such a product not reliable? What are the metaphysical theories of PC HiFi that cannot stand up to scrutiny? Today, let's talk about this topic.
A manufacturer launched a "HiFi" SSD, just ask you if you are afraid
Are "HiFi" class storage products really useful?
The article begins with a reference to the so-called "HiFi" SSDs being introduced by vendors, but this is not the first time in the industry that someone has done this kind of thing. Previously, the industry also appeared "HiFi-level" SD cards, "HiFi-level" memory, which was eye-opening.
The so-called "HiFi" SD card (picture from the Internet)
Not only will manufacturers use HiFi gimmicks to market storage products, but even users will agree that storage media will affect sound quality, for example, some people think that HDD sound quality is better than SSD. But in fact, does the storage medium really affect the sound quality? I am afraid that in principle, this is unreliable.
The beauty of digital music is that if there is no difference in data, there will be no difference in sound quality. Whether on CDs or other storage devices such as SSDs and HDDs, audio files are stored in the digital form of "01". It doesn't make any difference whether these "01s" are stored on a CD or compressed into lossless music stored elsewhere.
In a digital audio system, a typical music playback process looks like this. Audio data is read from the SSD, HDD and other storage media to the memory, and then the chip (CPU, DAC) reads the data decoding from the memory, converts the audio data into an analog electroacoustic signal, and finally transmits it to the sound element such as headphones or speakers through the amplification circuit, so that the human ear can hear the sound.
Using the idea of analog circuitry, "filtering" the memory module to improve the sound quality is simply ridiculous
In this process, storage media such as SSDs, HDDs and memory are only responsible for handing over the data to the chip intact, and in the process of data becoming sound, they do not work, so as long as the data is not wrong (there is an error correction mechanism, it is basically impossible to make mistakes), there will be no impact on sound quality.
We can make a less rigorous analogy - the text is printed on the book, the person memorizes the content of the book in his head, and then recites it, and the effect of the recitation is obviously not related to the paper material of the book.
Based on this principle of digital music, as long as it is a functional memory, it will not affect the sound quality. In the same way, cables that transmit data, such as USB cables, network cables, etc., as long as the quality is qualified and meets the standards, will not improve or damage the sound quality. Instead of spending money on "HiFi" hard disks and USB lines, why not spend more time collecting higher quality digital audio sources and opening an Apple Music member to listen to high-definition PCM audio?
Is CD sound quality better than lossless compression formats?
The author has seen more than once that enthusiasts are arguing about whether the sound quality of lossless music is really "lossless", and the "ironclad evidence" is that after the lossless music is restored to the Wav format, the file Hash found that there was a difference. What's going on here? Does it mean that the so-called "lossless" compression is actually a deletion of audio data, and if you want to improve the sound quality, you have to rely on CDs? This is not the case.
After losslessly restored to Wav, Is Hash different from the original Wac?
CDs themselves are the carriers of digital music. After music is digitized, it is often packaged as a PCM-style CD. PCM audio in CDs is generally 16-bit, 44kHz format, usually stored in the Wav format. The audio in a normal CD is PCM, but PCM is not limited to ordinary CD specifications. PCM audio can also do 24bit, 384kHz such high-definition audio specifications, such a high-specification audio in the Blu-ray video audio track is more common, generally speaking, few people specifically use high-definition audio to do music products, but in recent years, with people have a higher pursuit of sound quality, high-definition audio specifications are becoming more and more common, such as Sony to promote Hi-Res hd audio, Apple Music has also begun to provide higher than the CD specifications of high-definition PCM.
Apple Music is lossless and there is no extra charge for Apple Music, and PCM audio can be up to 192kHz in specifications
Whether it is a 16-bit, 44kHz CD specification PCM, or a high-definition audio PCM, their original waveform Wav files can be suppressed into lossless audio. This process really does not have any impact on the sound quality.
The so-called lossless compression, we are in contact with a lot, such as a rar document, unzipped out of the file and before compression is completely different, this is lossless compression. The same is true for lossless audio, which is converted back into the original Wav waveform file and the audio data makes no difference.
The waveform of lossless audio is the same as the original data, there is no difference
The reason why the hash value changes after the lossless audio is restored to the Wav format, there may be two situations.
◆ Artificially processed the audio data during transcoding. For example, some enthusiasts, when transcoding the PCM of the CD specification into a lossless compression format, SRC becomes a higher specification of audio, so that the sound may be more delicate (the principle is similar to image interpolation). In such cases, lossless compression can indeed be "lossy".
◆ Metadata was added when transcoding. Some lossless music transcoders add additional metadata information to the audio file when compressing audio. This part of metadata information is often used to store information about music, such as the song title, singer, album, etc., which has nothing to do with sound quality. Some lossless music encoding tools, when converting the format, write the content of this file "encoded by so-and-so" in the metadata, and the information is not removed after conversion back to the Wav file, so it causes the difference between the files before and after compression. But this difference has nothing to do with sound quality, and lossless compression is still lossless.
Having written something in metadata, the Hash of the Wav file is different, but the sound quality is exactly the same
But some friends swore to be sure, personally received the goods with their ears, and found that the lossless sound quality was indeed a little bit worse, what is going on? Unfortunately, this may have been pitted by the fake damage.
The appearance of false lossless is often for gimmicks, seeing that a song is MP3, people who have requirements for quality may ignore it; but if you see that it is lossless, properly collect the song! In this case, lossless means traffic, but what if there is no lossless music or original source in hand? It's up to deception. So some unscrupulous music websites make MP3s fake and lossless, and users download them to think that they have found treasures, but in fact, they have only picked up a bunch of useless data that occupies extra space.
So how to identify fake damage? In fact, the most important feature of false losslessness is the lack of high-frequency information, which is clear at a glance after opening the waveform chart. But opening the waveform graph is too troublesome, using some software, you can also do this. The author here recommends the use of Foobar2000 for non-destructive identification, the following is a detailed tutorial.
In simple terms, Foobar2000 has a rather magical non-destructive recognition plug-in "fooCDtect". After installing this plugin in Foobar2000, you can find the option to "Distinguish Lossless" through the "Convert" menu. You can select N songs in the playlist and make non-destructive discrimination all at once. If the result shows "CDDA-100%", then it must be true lossless, otherwise it may be false lossless.
Can I change the playback software to improve the sound quality?
Many friends believe that switching to some players such as Foobar2000 can greatly improve the sound quality.
Changing software can improve the sound quality, which seems to be a matter of course? After all, changing a browser can improve internet speed, changing a game driver can improve the smoothness of the game, etc., everyone has seen a lot, and the impact of software on the final output effect is often obvious. But this is not always the case.
First of all, Foobar2000 in the official Q&A page, it is clear that Foobar2000 does not improve sound quality. Secondly, from the principle of PC output audio, Foobar2000 does not have a positive impact on sound quality.
The official Q&A shows that Foobar2000 does not improve the sound quality, and people hear that the improvement in sound quality is just brain YY
PC to play a piece of audio, the player's job is to decode the audio file into PCM, and then through the audio interface of the Win system (MME, DirectX, WASAPI, ASIO, etc.), output to the sound card and other DAC devices for digital-to-analog conversion, and then through the amplifier, headphones and other hardware, you can hear the sound. In addition to parsing audio files, the player has no impact on the sound quality of the entire audio playback process. When parsing audio files, as long as the algorithm is normal, the results will not vary - just as you use any compression software to decompress the same rar document, the extracted things are the same. Therefore, with different players, the sound quality will not be different.
However, some friends swear that after switching to Foobar 2000, the sound quality is indeed better. This can be due to the following reasons.
◆ Turn on the sound effect. If you turn on the sound effects of the player, the player will not decode the audio file into a PCM audio stream as it is, but will add ingredients to it. Foobar2000 is also a player that supports many sound effect plug-ins, many people install are not the original Buddhabar2000, may be turned on by default. In the end, it makes sense to have a different sense of hearing – note that a change in hearing does not mean an improvement in sound quality.
Foobar 2000 supports DSP sound processing such as equalizer, which can indeed make the sound different, but many people can't distinguish between sound quality and sound effects
◆ Use an audio interface with less interference. As mentioned earlier, the audio interface of the Win system includes MME, DirectX, WASAPI, ASIO and so on. Some of these audio interfaces are low-priority APIs that are not exclusive to the player. For example, using the system default channel, when the player plays the audio of the 44.1kHz sample rate, QQ suddenly has a notification tone, the sample rate of the prompt tone is 48kHz, then the system will mix the sound played by the player and the QQ prompt tone, and then output it after SRC. As a result, the sound quality will naturally decline. The Foobar2000 supports exclusive interfaces such as WASAPI and ASIO, which can ensure that music playback will not be interfered with - the negative effect is that you may not be able to hear the QQ prompt. Using interfaces such as WASAPI, there is also a more metaphysical statement that jitter can be reduced, but no one can blindly detect the difference, so I will not expand here.
Using exclusive channels such as ASIO and WASAPI can indeed reduce interference and latency in terms of sound quality
◆ Use a higher specification audio file. By installing plug-ins, the Foobar2000 can support HD audio, or DSD audio, with specifications far exceeding CD sound quality. The reason why HiFi enthusiasts love to use Foobar2000 is also a big reason. In addition, Foobar2000 supports a relatively good SRC algorithm, which can bring low sample rate audio to SRC to high sample rate. As a result, the waveform becomes smoother and the sound will be more delicate. From this point of view, Foobar2000 still has a positive effect on sound quality. However, as the official Q&A of Foobar2000 says, many other mainstream players also support this, and foobar2000 is no different from them.
Foobar 2000 supports DSP algorithms such as resampling SRC that can change the sense of hearing, but this is not a patent of Foobar 2000
summary
The popularity of many HiFi "metaphysics" has a lot to do with the idea of "taking it for granted". In the era of digital audio, many links can no longer use the theory of analog audio to apply, and the reliability and fidelity of digital audio are unmatched by analog audio.
The popularity of wireless Bluetooth audio means that digital audio has jumped to a new level in the market, and the headphone cable that transmits analog signals is replaced by Bluetooth, which transmits digital signals. In the new era of digital audio, what kind of "metaphysical" theories will emerge? I hope that the "metaphysical" view that "Bluetooth 5.0 sound quality is better than Bluetooth 4.2" will not become popular.