Listening to music is one of the greatest ways to relax after a long day or focus on scratching off our to-do lists. It’s something that we often take for granted because audio streaming is actually an extremely complex process.
And this complexity has only grown now that wireless technology, like Bluetooth, has come into the picture. But for people who want a truly authentic sound, it’s necessary to use a wired analog cable to try to match a song’s original recording.
But when we play a CD or a tape, how exactly does the soundwork? What is going on behind the scenes that’s able to bring us the gift of music wherever we go? It’s thanks to DACs, so let’s take a look at what they are and how they function.
DAC stands for digital-to-analog converter.It takes digital data and transforms it into an analog audio signal. When you’re listening to a recording on a CD player or even on your phone, you’re actually listening to an analog signal that was converted from a digital file.
DACs really became popular in the early 1980s during the rise of CDs. Compact discs were able to allow for digital recordings in studios, which are much easier to work with when compared to analog recordings that require a physical copy.
An analog recording is accomplished by imprinting an audio signal directly onto a master tape (via magnetization) or a master record (via grooves). Copies of these can be made on cassettes and vinyl records but require tape players or record players in order to replicate the sounds.
Digital signals take those signals and convert them into a series of computational values. This is a process called encoding, in which the data is simplified into numerical terms so that it may be distributed elsewhere. Digital files can be copied onto discs, hard drives, or streamed through auxiliary cables.
Years ago, when record and tape players were the only ways to enjoy music, we didn’t need DACs. This is because the data never gets transmitted into a form other than analog, as this is used in both recording and playback.
Analog is limiting, however, especially with new pieces of technology requiring digital 3.5 mm jacks or USB cables to stream our favorite albums. This is why we need digital-to-analog converters so that we can enjoy new technology without having to sacrifice music.
You can get external DACs to convert films from analog to digital on your computer. These usually look like a small box with a wire USB output and digital/ analog inputs.
However, your phone, computer, and television have DACs inside of them! Most DACs are implanted inside of the device, so you never actually see them. Regardless, if you're able to hear sound, it means that there’s a DAC in there somewhere.
To best exemplify the DAC conversion process, let’s look at an example of how a sound might be recorded and then played back:
Something important to note is that even if your device incorporates a DAC, it might not be one of high quality. This can account for a difference in audio quality depending on the type of speaker or headphones that you are using.
If you’re an audiophile, you know how much of a difference great sound can make when listening to music or watching a movie. But even if you’ve never paid much mind to this, good quality sound can revolutionize the way you appreciate music.
Bluetooth headphones and speakers have become the new normal. In 2015, over 40% of Americans have Bluetooth enabled on their phones, and this number has only risen since then. It’s an extremely convenient technology, but it can’t really match the same audio quality as a wired system. Bluetooth files become so compressed during transmission that they lose some of the original quality. This is called lossy audio.
Analog stereo systems will always be able to give you the best sound, as audio remains uncompressed. This is known as lossless audio, meaning that no quality is lost between recording and playback. These are your record players and cassette players that have an authentic tone unmatched by digital devices.
Digital systems have lesser quality than analog, yet they do remain of a higher standard than Bluetooth. You’ve used a digital output before if you’ve ever used the headphone jack on your phone.
You can make wired headphones sound even better if you get an amplifier. Not only will this make your digital headphones compatible with Bluetooth, but it uses Sony’s LDAC audio codec to enhance the sound that comes from your music player. This is an efficient way to improve your sound quality if you use a digital system.
Because of the way that Bluetooth works, it is unlikely that we will see a day where audio transmitted wirelessly matches the quality of audio streamed through cables. With that said, Bluetooth is constantly updated and is nearing CD-level quality.
The company Qualcomm has created a Bluetooth codec called aptX, which has a variation by the name of aptX HD. This is a codec that was specifically engineered with quality in mind, and it gets extremely close to the sound quality of CDs. Devices that utilize aptX HD will sound authentic when compared to most standard Bluetooth peripherals.
There’s also the problem of latency when it comes to Bluetooth devices, as it can take some time for the information to travel through the air. The standard latency of an SBC device is 170-270ms, compared to only 7ms from a wired connection. AptX has another variation called aptX Low Latency. AptX LL has a latency of only 30-40ms, virtually eliminating syncing issues that are common with most Bluetooth gadgets.
But if you have an analog or digital system that you really love because of its crisp sound, you can use a Bluetooth receiver to instantly make them wirelessly compatible. This lets you retain the quality that you love while also allowing you to stream your favorite playlists from Apple Music or Spotify.
Sound is a tricky and complex topic, but it is vital to our daily routines. What used to be reserved for tape players and record players can now be transmitted through so many different mediums thanks to digital-to-audio conversion.
DACs convert the originally recorded analog sound into a series of computational values, allowing them to be copied onto CDs or streamed through the internet. While the conversion process can cause the quality to lessen, it makes transmission much simpler.
And while Bluetooth technology is not as pristine as wired, you can combine the accessibility of wireless tech with the quality of wired peripherals by using transmitters and receivers to your advantage.
Although complicated, it’s important to appreciate the ingenuity behind sound recording and playback. Without DACs, we wouldn’t be able to enjoy music in many of the ways that we can now.