Does digital sound better than analog?

        Tech | Audio
Sound can be visually represented on a graph as waves. By comparing this wave to the graphics below, you can easily see how digital sampling processes sound data.
Sound can be visually represented on a graph as waves. By comparing this wave to the graphics below, you can easily see how digital sampling processes sound data.
©2008 HowStuffWorks

Which is better, digital or analog sound? Is there really a difference? Do you have to own really expensive audio equipment to discern any differences? And does it really matter?

Before we jump into the argument, we should take a quick look at what makes a sound digital or analog. It all has to do with how you record a sound. An analog recording copies sound as a continuous electronic signal. A graph of an analog signal might look like this:

Digital media includes CDs, DVDs and sound files. Uncompressed digital sound files tend to be very large. Often, audio engineers will compress these files to make them more manageable, but this can affect the sound quality.

Today, advances in analog-to-digital conversion methods have improved the quality of digital recordings. Some people say that high sampling rates and increased precision have erased any distinction between digital and analog. Others disagree -- sometimes passionately. There's a sizeable population of audiophiles -- people who want the highest quality in sound systems possible -- who insist that analog systems provide a better sound.

What are the differences in the actual sound of analog and digital recordings? Keep reading to find out.­

 

Analog and Digital Signals

­Are analog fans living in the past?
­Are analog fans living in the past?
Dan Talson, iStockphoto

Sound is naturally an analog signal. An analog signal is continuous, meaning that there are no breaks or interruptions. One moment flows into the next. If you were to hum a descending note, people hearing you would be able to detect the change in pitch, but not point to specific moments when the pitch jumped from one note to the next.

Digital signals are not continuous. They use specific values to represent information. In the case of sound, that means representing a sound wave as a series of values that represent pitch and volume over the length of the recording. In a primitive digital recording of that descending note you hummed, you'd hear a single long sound as a collection of shorter sounds.

Some audiophiles argue that because analog recording methods are continuous, they are better at capturing a true representation of sound. Digital recordings can miss subtle nuances. But as digital recording processes improve, digital devices can use higher sampling rates with greater precision. Although the signal still isn't continuous, the high sampling rate can create a sound similar to the original source.

Before the 1970s, musicians recorded their performances on analog recording equipment. Microphones recording the sound generated an analog wave that other devices would then transfer directly to the proper media (usually magnetic tape). Assuming the recording artist used reliable equipment, the sound recorded was an accurate representation of the original sound.

With digital recording, audio engineers convert analog waves into digital signals. There are many different kinds of equipment that can convert analog to digital. Some audio studios record a performance on an analog master tape first, then transfer the sound to a digital format. Others will use special equipment to record directly to digital.

Early digital recordings sacrificed fidelity, or sound quality, in favor of reliability. One of the drawbacks of an analog format is that analog media tends to wear down. Vinyl albums can warp or get scratched, which can dramatically impact sound quality. Magnetic tape eventually wears out and is vulnerable to magnets, which can erase or destroy information stored on the tape. Digital media like compact discs can reproduce sound indefinitely.

Another advantage digital media has over analog is that you can make as many copies of the original sound file as you like without hurting it. Eventually, even an analog master recording isn't going to sound as good as the original performance. As long as nothing corrupts a digital file, it will stay the same no matter how much time has passed or how many copies engineers make.

Today, technology in the audio recording industry is so advanced that many audio engineers will tell you there's no detectable difference between analog and digital recordings. Even if you were to use the best stereo equipment, you shouldn't be able to identify one medium versus the other just by listening to the sound. Many audiophiles disagree and claim that the analog format is still supreme.

So what are the arguments that audiophiles use to support their love of the analog format? Find out in the next section.

Analog vs. Digital: The Verdict

Should we all just switch to digital systems?
Should we all just switch to digital systems?
Chris Schmidt/iStockphoto

Some audiophiles believe that digital recordings fall short when it comes to reproducing sound accurately. They use an intricate language filled with jargon to describe an audio system's capabilities or shortcomings. Most of their criticisms deal with sound frequency.

Humans can hear sounds ranging from 20 hertz (Hz) to 20 kilohertz (kHz) [source: Hyperphysics]. A sound wave's frequency corresponds to our perception of a sound's pitch. The higher the frequency, the higher the pitch we hear.

Audiophiles describe an audio system's sound quality regarding different frequencies by using terms like full, warm and airy. A full or warm sound comes from a system that reproduces low frequencies well. An airy sound means that the music reproduced gives the listener the impression that the instruments are in a spacious environment and usually refers to sounds in the high frequency range.

Some audiophiles say that vinyl albums perform better in the lower frequencies, meaning they provide a warm sound. They argue that compact discs aren't as accurate at reproducing sounds at this range. Other people insist that there is no detectable difference between a well-produced digital file and an undamaged vinyl record.

An audiophile would likely point out that your sound system will be the most important factor when listening to music, not the media you put into it. But assuming you've put together a really strong system that can handle both analog and digital formats, which format should you choose when shopping for a new album?

It depends on the recording method. If the recording artist used an analog format to create the master recording, audiophiles would argue that an analog copy of the music is best. That's because there would be no need to convert the sound from analog to digital. The copy should be an accurate representation of the original track.

But if the artist used digital recording, then it would be best to buy the album on CD. In order to press a vinyl album from a digital recording, audio engineers must first convert the music from a digital signal back into an analog sound wave. Any time engineers have to convert a recording from one format to another, there's a chance that the quality will suffer.

In the end, the perception of musical quality is somewhat subjective. Two people standing in the same room listening to the same music might have very different opinions regarding the quality of the recording. One might describe the music as warm and airy, while the other could say it was harsh and flat. That can happen whether the listeners use digital or analog media.

So bottom line: which is better? After much research and subjecting ourselves to hours of listening to music, we've come up with an answer. We're going to have to call this one a tie.

To learn more about audio systems and related topics, tune in to the links on the next page.

Does digital sound better than analog? Author's Note

Author Jonathan Strickland
Author Jonathan Strickland
HowStuffWorks.com

I knew I'd be walking on thin ice with this article. If there's one thing guaranteed to launch a shouting match among music fans, it's the old digital-versus-analog debate. While there are audiophiles who will protest to the grave that analog formats like vinyl records provide a truer, richer sound than digital formats, there's not much hard evidence to support the claim. Sure, if you listen to music on a substandard system, it's not going to sound very good. And if you encode digital music using a low bitrate, the sounds you get as a result may be less than pleasing to the ear. But if you're using a lossless digital format and a decent sound system, it's very difficult -- perhaps even impossible -- to tell the difference between analog and digital. I believe that what some audiophiles truly value is the ritual of listening to analog music. Taking a vinyl album from a sleeve, placing it on the turntable and delicately positioning the needle gives the experience of listening to music a gravity it might not otherwise possess. How could that not sound better?

Sources

  • "Analog vs. Digital." Grunt Productions. http://www.gruntproductions.com/recorded/analog_vs_digital.htm
  • "Analog vs. Digital and Contemporary Analogue Mastreworks." Contemporary Analogue Mastreworks. Aug 19, 2006. http://www.segall.com/atr.html
  • Elsea, Peter. "Analog Recording of Sound." UCSC Electronics Music Studios. 1996. http://arts.ucsc.edu/EMS/Music/tech_background/TE-19/teces_19.html
  • Partyka, Jeff. "Analog vs. Digital: no clear victor." Emedia Professional. Dec 1999. http://findarticles.com/p/articles/mi_m0FXG/is_12_12/ai_63973540
  • "Sensitivity of Human Ear." HyperPhysics. http://hyperphysics.phy-astr.gsu.edu/Hbase/sound/earsens.html

Does digital sound better than analog: Cheat Sheet

Stuff you need to know:

• Analog sound waves are continuous, meaning there are no interruptions or breaks. Digital signals aren't continuous -- they create short bursts of sound of the correct pitch and volume and collect them together to simulate a sound wave.

• Audiophiles value a concept called fidelity, which refers to how true a recorded sound is to the original source of that sound. A high-fidelity recording should sound almost as if you were present during the original performance of the audio.

• If an audiophile tells you that a particular recording has a warm sound, it means that the medium has captured the lower frequencies faithfully.

• Ultimately, the quality of an audio recording is somewhat subjective and dependent upon the listener. Two people may hear the same recording in the same set of circumstances and yet draw different conclusions about the quality of the sound.

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