Analog vs. Digital Audio Controversy Resolved

Blažo Guzina

 Analog vs. Digital Audio Controversy

   

Compact Disc 4  3/4” (12 cm) 200 - 500 rpm	Vinyl single record 7” (18 cm) 45 rpm
Vinyl LP record 12” (30 cm) 33  1/3 rpm

 

 

Vinyl’s much-hyped return to radio 

 

Recently, dedicated radio listeners were surprised by the announcement that radio stations in Europe and the United States intend to drag out turntables to play vinyl LPs, invoking the supposed “warmth” some self-described audiophiles associate with an LP’s sound.

For those of us with a long memory, the news came as a reminder of how before the digitization of audio 40 years ago, recording engineers and DJs in a radio station control room would use at least two turntables and two or three tape recorders in their everyday routine. Philips and Sony then gave us the Compact Disc — a new type of digital “gramophone record,” heralding a new era of mass communication and consumerism. It was the biggest breakthrough in sound reproduction since Thomas Edison invented the phonograph in 1877.

Consequently, radio stations gradually phased out vinyl single and LP records in the mid-1980s and went to CDs. Huge turntables and tape recorders the size of electric cookers disappeared, replaced by small CD players. As far as the sound quality was concerned, CDs eliminated a number of problems such as clicks and pops and occasionally the embarrassment of a stuck needle — and listeners could hear the benefits over the radio.

Those pops and clicks 

On a well-maintained record, pops and clicks are often not audible and should therefore not distract from the listening experience. However, no evidence exists of a record with absolutely no pops or clicks. They are introduced at virtually every stage of vinyl production, from cutting the lacquer to the pressing and playback — more often, the result of static discharges. Although topical treatments on the record may mitigate this effect, they cannot eliminate it. With use, and over time, groove wear is inevitable. The pops and clicks that result are noticeable at higher frequencies, and even using an expensive, modern pick-up and stylus cannot solve the problem.

A compact disc digital audio system, on the other hand, utilizes a laser optical pick-up with a unique high-density recorded disc. As shown in Table 1, the main advantages of a CD compared to a vinyl LP are a broad bandwidth allowing a frequency response characteristic of 20,000 Hz, impressive signal-to-noise ratio, excessive dynamics ratio and immeasurable wow and flutter, with an extremely low percentage of harmonic distortion.

No evidence exists of a record with absolutely no pops or clicks.

The overall result is a quality of digitally recorded and reproduced sound that is a step closer to achieving the faithful representation of the sound at the scene of recording, be it a concert hall or studio.

Music lovers, musicians and radio and television professionals greeted the CD format with open arms, happy to finally enjoy quality in a source of recorded sound that would not deteriorate through years of everyday use.

On a theoretical level, there’s, therefore, no reason to consider the case that vinyl sounds better. There are built-in problems with using vinyl as a data encoding mechanism with no CD equivalent. Vinyl is physically limited by the fact that records have to be capable of being played without skipping or causing distortion. This both limits the dynamic range — the difference between the loudest and softest note — and the range of pitches of the frequencies of sound one can hear. If the sound gets too low in pitch, less audio can fit in a given amount of vinyl. If the sound is too high, the stylus has difficulty tracking it, causing distortion. So, engineers mastering for vinyl often cut back on extreme high or low ends, using a variety of methods, all of which alter the music.  

General specifications	Compact Disc	Vinyl LP
Diameter  [mm]	120	300
Disc thickness  [mm]	1.2	1.5 – 2.3
Playing time  [min]	74	50 – 60
Revolutions per minute	200 - 500	33.33
Rotating speed [m/s]	1.2 – 1.4	approx.  0.4
Track pitch [mm]	1.6	approx. 100
Bandwidth  [Hz]	20 - 20000 (±0.3 dB)	30 - 20000 (±2 dB)
Dynamic range [dB]	90	51
Signal/noise ratio [dB]	> 90	56
Channel separation [dB]	> 90	25 - 35
Total harmonic distortion [%]	0.005	0.2
Wow and flutter [%]	Immeasurable	0.03
Channels	2	2
Material	Al + PVC	Vinyl
Expected lifetime	Unlimited	Approx. a few hundred hours
Laser/pick-up lifetime [hours]	5000	400 - 800
Impact of dust, scratches and static electricity	Immeasurable	Increases the noise

     Table 1

The final verdict 

Nevertheless, today, some people prefer listening to music on vinyl rather than on CD or other digital formats. Their reasons should have nothing to do with actual sound quality but more with the tactile characteristics of vinyl, visual aspects such as larger album artwork and the playback ritual. Others prefer listening to CDs for a different set of reasons. There is nothing wrong with preferring vinyl to CDs, MP3 and digital audio in general, as long as the preference is honestly stated on emotional terms, or is precisely quantified and tied to subjective experience, and not obscured with erroneous and sometimes pejorative technical appeals.

Their reasons should have nothing to do with actual sound quality but more with the tactile characteristics of vinyl, visual aspects such as larger album artwork and the playback ritual.

As for the “warmth” of vinyl, that can generally be ascribed to a less accurate bass sound. The difficulty of accurately translating bass lines to vinyl without making grooves too big means that engineers have to do a lot of processing to get it to work, which changes the tone of the bass in a way that, apparently, many people find aesthetically pleasing.

For audio professionals, however, the arbitrary claims that the sound impression of LPs compared to CDs is allegedly superior is as acceptable as a claim that traveling from Paris to Brussels is more comfortable in a four-horse chariot than in the latest model Tesla.

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Originally published: Vinyl’s much-hyped return to radio    

RedTech Magazine N°11, Sept. – Oct. 2022, pp 44 – 45.

 

 
   

 

 

Analog vs. Digital Audio Controversy

 

Part II

 

 

Vinyl vs. Digital 

The controversy continues. 

Or, is it time to put the whole matter to rest?

 

Judging from readers’ reactions to my piece in RedTech Magazine Sept/Oct 2022 about vinyl’s return to radio, one can’t help concluding that comparing CDs, MP3 and digital audio in general to vinyl records is the musical equivalent of comparing digital to film photography.

That’s not entirely accurate. First, there is not such a glaring difference between digital photography and high-quality film photography. Furthermore, advocates for film photography as opposed to digital are not as vocal as those advocating vinyl vs. digital sound.

The debate over whether analog or digital sound is preferable is touchy and about as resolvable as arguing about the beauty of the Mediterranean or Caribbean beaches. There are people who swear by either side, so the apparent “war” between analog and digital sound advocates looks set to continue.

Moreover, as professionals and analysts on the technical side of the subject have noticed, as much as the purists and retro aficionados continuously insist that vinyl sounds “purer” and “better,” their progressive counterparts firmly believe in the accuracy of the technology and point out that digital audio is the dominant choice today for professionals and consumers alike. Although it is evident that, from a technical standpoint, digital audio is far superior to analog, a certain niche of people will still prefer analog to digital sound, even though vinyl is prone to physical interference and noise and mechanical degradation over time.

Into the groove

Notably, this audiophile niche is expanding, and old-fashioned vinyl records are even experiencing a renaissance among musicians, recording artists and Hi-Fi enthusiasts. They tend to ignore the fact that a turntable’s stylus may prematurely wear or break and it is constantly wearing the record’s grooves. Additionally, during playback, the turntable’s cartridge has limits on what grooves it can successfully track. A stylus is designed to track grooves of a finite modulation width, i.e., a track pitch of approximately 100 micrometers [μm]. This also involves limits on the acceleration and velocity the record can take.

As a devoted fan of British and U.S. rock and pop heritage, I can recall how, back in the 1970s, I used to listen to eponymous album “The Jimi Hendrix Experience,“ where the best tune (in my opinion), “Hey Joe,” was the last track on side one. Due to the above-described mechanical restrictions of the turntable’s stylus capabilities, and the small diameter of the record’s grooves spire, the stereo sound on the song was unstable, even slightly distorted, much to my disappointment.

Many years later, while I was writing a book “Osam dana nedeljno – Priča o Bitlsima” (“Eight Days a Week — A Story of the Beatles”), published in Serbian, I recalled how, in the middle of ’60s Beatlemania, Paul McCartney used to complain about the poor quality of his bass guitar sound reproduction on gramophone records, compared to the sound produced on stage. Paul asked Beatles’ producer George Martin what could be done in the studio, and he calmly explained that he was forced to turn down the volume of Paul’s bass guitar to prevent high distortions due to the lack of technical possibilities of a gramophone record. On stage, the young and enthusiastic McCartney used to turn the potentiometer up to the top boost position on his VOX AC 35 amplifier. If George Martin had recorded his bass guitar sound in the studio as Paul demanded, the gramophone stylus would certainly have jumped out of the record groove.

The final say

Unfortunately, despite decades of arguments, there is no technical proof of the sonic superiority of vinyl compared to CD, no matter how vocal the pro-LP lobbies have been. Digital sound, in general, is evidently superior to analog, as much as digital radio and TV are superior to their analog counterparts. Even in the record production plants, most LPs are produced based on digitally recorded, mixed and mastered sound. For at least the last two decades, it was common practice to use the same CD masters on vinyl releases.

It is useful to remember that the term “analog,” by definition, means that the signal is not and cannot be a perfect reproduction of the original. It is merely a version of the existing signal, corrupted in the process of recording, mastering, producing and reproduction. No matter which recording process is used — analog or digital — both are created by a microphone turning air pressure into an electrical signal. An analog recording is made by then imprinting that signal directly onto the master tape (via magnetization) or master disc (via grooves), from which copies can be made into cassette tapes and vinyl records. Digital recordings take that analog signal and convert it into a digital representation of the sound, which is essentially a series of numbers for digital software to interpret. After the analog signal is digitized, the recording can be copied and placed onto a CD, DVD or hard drive or streamed online, and in the case of broadcasting, the final product, the sound we hear, is inevitably the result of analog AM, FM or digital — DAB, DRM or HD Radio type of encoding and modulation.

Despite their brief resurgence on air, LPs will finally rest in peace, leaving no chance that their sound could ever challenge their digital counterparts.

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Originally published at Redtech, May 27, 2023,Vinyl vs Digital, the controversy continues.

  

From the same author, newest book:

"ACOUSTICAL DESIGN OF BROADCASTING AND RECORDING STUDIOS 

Requirements, Recommendations, Architectural guidelines"

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