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Today, pretty much everything seems to be digital, whether it’s a watch, a television or a book, you can’t escape the fact that we are living in a digital world. However, analog devices are still current in our day-to-day life.
We are going to take a look at the difference between analog and digital, how they compare and which of the two is more accurate.
Regardless of where you stand on the discussion of the two signals, both digital and analog have their merits. When it comes to discussing the two types of signals and accuracy, analog is more accurate than digital.
Whether referring to a device or a piece of music, analog is more accurate because it provides a better representation of the recorded information. In the case of recorded sound, analog offers the true representation of the sound, whereas digital is not a recording of the actual sound and is not as exact as analog information.
Let’s take a deeper look at why analog is more accurate than digital, the processes and challenges surrounding converting analog to digital, and why analog will always play a role in daily life regardless of digitalisation.
WHY IS ANALOG MORE ACCURATE THAN DIGITAL?
The following section will present a couple of examples what and why analog is more accurate than digital.
We can relate this to a watch. An analog watch is likely to be much more accurate than a digital one because it uses high-precision movement to measure passing time, and generally the most expensive watches in the world are analog ones.
When considering sound signals, analog recording is made up of bumps and dips and as mentioned earlier in the article, is believed to be the true representation of the sound at the moment it was recorded. Digital is not a recording of the actual sound, but rather a combination of zeros and ones combined in the form of machine language, it is not as exact as analog information.
Although analog is more accurate, digital is still used because unlike analog, it is non-linear and can be edited or played back at any point. This is a huge timesaver and results in a better longevity.
Whilst digital signal trumps analog in various other aspects, accuracy is not one of them. Think of it this way, analog signals correspond the variations of air pressure of the original sound, and digital signals are a series of numbers that correspond to the sound’s continuous variations. Digital signal numbers need to be reconverted to analog signals before they can be listened to.
SIGNALS. WHAT ARE THEY AND HOW DO THEY RELATE TO ANALOG AND DIGITAL TECHNOLOGY?
Technologically speaking, analog and digital can be broken down into signals. A signal is an electrical current that is used to carry data from one system or network to another and we encounter different types of signals in our daily lives.
Whether you are watching television, listening to music, scrolling through your social media, or simply talking with a friend over the phone, both analog and digital signals cannot be avoided.
As we have witnessed throughout the decades, people accept the adoption of technology easily enough, but discussion about the two types of signals can be a delicate one. Examples of digital devices are hard drives, CD recorders and most processors in a computer. Land-line telephones, VCR’s, photocopiers and record players are all considered analog devices.
WHAT’S THE DIFFERENCE BETWEEN ANALOG AND DIGITAL SIGNALS?
So, you may be wondering, what’s the difference between an analog and a digital signal?
In its most basic form, the two signals are defined differently as the following; An analog signal is a continuous wave that keeps on changing over a period of time, and a digital signal is a wave that carries information in binary form.
An example of an analog signal would be the human voice, whereas signals used for transmission in a computer are classed as a digital signal.
SIGNALS AND SOUND. CONVERTING ANALOG TO DIGITAL AND HOW TO IMPROVE ACCURACY
The accuracy of a converter relates to how many bits, from conversion to conversion, can be duplicated. In other words, accuracy reflects how true the ADC’s output reflects the actual input.
When using an analog-to-digital converter (also known as ADCs) it is important to understand the accuracy of the system, and simply increasing the performance or resolution
of the ADC will not particularly improve the accuracy. ADC errors need to be minimized in order to improve accuracy when converting from analog to digital.
To minimize the ADC errors with regards to the external environment, be wary of the reference voltage and power supply, remove the analog-input signal noise, match the ADC dynamic range to the maximum signal amplitude, and match the analog source resistance.
DON’T CONFUSE ACCURACY WITH RESOLUTION
An easy mistake to make is to confuse accuracy with resolution. The terms accuracy and resolution are not the same but are related and should not be used interchangeably. Think of accuracy and resolution as cousins, but not twins.
Simply put, accuracy is just error, or how much the value under deviates from its true value. Accuracy error is often also referred to as sensitivity error. Resolution is simply how finely the value measured can be represented or displayed.
Even though a system may have 12 bits of resolution doesn’t particularly mean it will be able to measure a value to 12 bits of accuracy.
It is important to understand that both accuracy and resolution influence the signal chain, and it must be kept in mind that not all components are created equally. Increasing the performance or resolution of a ADC converter will not particularly increase the measurement accuracy. Other aspects such as front-end noise need to also be considered.
SAMPLING RATE AND BIT RATE
When you download digital music, it’s likely that you will be given the option of downloading the same track at different bit rates. The bit rate is the amount of information captured each time the track is sampled.
A higher bit rate means that more information is captured and the analog information is converted into digital information more accurately. Higher quality tracks may have a higher bit rate, but the tracks will be a bigger file and take up far more space on your computer, which means it will also take longer to download.
It’s very common for music to be digitally converted for CDs and MP3 tracks with a sampling rate of 44.1kHz (about 44,000 times per second). The sampling rate needs to be roughly twice the highest frequency of sound in your wave, and since human hearing is limited to about 20kHz, that suggests we need a sampling rate of at least 40kHz.
The typical bit rate for an MP3 track is around 128kbps (128,000 bits per second), though higher quality tracks have a bit rate between 128kbps and 256kbps (up to 256,000 bits per second).
Which rate you choose will depend entirely on the product that you intend to deliver. It can also depend on the type of engineer working on the project. Some engineers trust that today’s sample rate conversion is good enough and it’s not necessary to choose a rate based on keeping the math simple. For these engineers, a higher rate is generally considered better.
THE RETURN OF ANALOG TECHNOLOGY AND PRODUCTS
Although we live in a digital world, we are starting to see a resurgence in analog technology. From a steady increase in the sales of vinyl records and paper books, to an increasing appeal of physical toys, digitally-minded youngsters are being won over by companies such as Lego, whilst more traditionally digital companies such as Nintendo are also seeing the value of the production of physical figurines.
The resurgence in analog could be related to the issue of ownership. Digital music and games are instantly accessible through apps and consoles, yet they remain intangible. Analog therefore offers a more personal experience and connection to music, books and games.
In Japan, we have seen a steady increase in the sales of vinyl throughout the past decade, and it doesn’t seem to be slowing down. It won’t be long until the resurgence of vinyl will see the analog form of consuming music overtake CD sales.
The UK is also set to see the best year in three decades with regards to vinyl sales in 2020. In 2019, Rolling Stone said that “Vinyl records earned $224.1 million (on 8.6 million units) in the first half of 2019, closing in on the $247.9 million (on 18.6 million units) generated by CD sales.
The global vinyl market size is projected to reach $481.5 million by 2026, from $208.3 million in 2020, at a compound annual growth rate of 15% during 2021-2026. This figure could however change and swing either way. Considering the current climate and the lack of live music throughout 2019 and 2020, these challenges are likely to affect the projections for the coming decade.