In the vinyl vs CD debate, I am often asked why vinyl sounds so good and why compact disc (CD) was created if vinyl was a better medium in the first place? So let’s answer the question: “Vinyl vs CD – is vinyl higher resolution?”
Vinyl vs CD? This is not a simple question to answer, there is a great deal to consider. What makes a great medium? What makes a better medium? A bad record played back on a bad turntable sounds bad, but many, many CDs sound worse.
Stick around and take your time reading and digesting this. I didn’t write this article in five minutes. It’s based on my lifelong passion for the science of music reproduction and my professional involvement with high-end hi-fi gear both at home and in the studio.
Updated for 2020 including responses to butt-hurt CD evangelists who obviously didn’t read the bit where I said:
“Actually, I love the format (Red Book CD). For me, CD is the new vinyl.” Mike, years ago…
Vinyl has the potential, with good pressings and great playback equipment, to sound superb. By that I mean better than CD, better than any MP3 can ever sound and better than even high-res digital. This is not my opinion, its a statement of fact. Even with my super-specced up Musical Fidelity Tri-Vista Class A Tube DAC, now my PS Audio NuWave DSD, a good vinyl pressing of the same recording will often sound smoother, more relaxed and better resolved.
Note: I’m a scientist and working professional presenting what many years of experience and education have provided me. This article may not say what you want it to say, or what you think you know to be correct. I like and use, both formats. If you haven’t experienced the inherent advantages of each, you’ll find it useful in life to keep an open mind and make that a priority. There’s nothing more satisfying than learning something that changes your perspective.
CD – Perfect Sound, Forever, Right..?
Wrong. CD was the best consumer digital medium and format that the big manufacturers could create at the time. I was, and remains far from perfect though, any more than vinyl is. There are misinformed folks out there with a sparse technical understanding of the details. They scream vitriol like “CD is perfect” and “16 bit 44.1kHz captures all the information needed for a perfect recording”. This is clearly just technically incorrect, as we will see.
These comments are made by folks who don’t hear great gear every day, as I do. It’s like insisting the Earth is flat until you get to sail around it. Trust me, I wanted CD to be better as well. I hired one of the very first players in 1984 and was a very early adopter.
CD is not perfect. Sure, it’s cool, sounds pretty good and was a stroke of marketing genius. But outside the marketing hype, nobody who understands the science of music recording and reproduction would tell you it is. Recording engineers know it isn’t, home hi-fi enthusiasts with access to great vinyl and CD replay systems also know it isn’t.
Actually, no system is perfect, but to many who are interested in the extraction of the ultimate fine detail – ie resolution – vinyl is technically and sonically clearly ahead. It has to be, again simply based on science.
Note that we need to consider what metrics we are using. I’m specifically talking here about resolution, NOT noise, or pitch accuracy. Based on those two metrics, CD has the edge. But one can make a strong argument for the fact that the resolution of subtle micro-dynamic and high-frequency information that is lost in the digital sampling process is more important when reproducing music.
You might think of resolution as the ability to discern fine detail, to accurately portray two sounds of slightly differing levels. The simple answer is that, as a medium, vinyl is capable of higher resolution than CD, but we need to examine this in a little more detail. There are two important parameters to examine when looking at the Red Book standard which defines the technical specifications of CD. These are sample rate and bit depth.
Looking at bit-depth first, CD has a technical resolution of 2 levels, 0 or 1, raised to the power of 16. Sixteen represents the number of bits in each digital word and the bit depth specified in the Red Book standard. This gives us 2^16 or around 65,536 possible amplitude levels for any sample. Simply stated, a tone can have 65,536 different volume levels.
This is far from enough but was determined by the compute hardware limit in the early 1980s. More bits are always better, that’s why digital systems have moved to 18, then 20 and now 24 bits. Everyone who has heard 24 bit digital has heard the obvious improvement. How then can 16 bits represent perfect sound if 20 and 24 bits sounds better? See the problem?!
Sample rate determines the number of times the digital system captures a waveform sample, per second. For CD, this was set at 44,100 samples per second. This means that continuous tones in real music are chopped up 44.1 thousand times a second and joined together.
Sample rate determines the high-frequency response limit. Again, contrary to what raging commenters have asserted, whilst we may not hear above 20kHz, these high-frequency harmonics seem to be important because one can hear differences in systems that capture and reproduce these frequencies.
Not only that but the filters required to avoid aliasing artifacts limit high-frequency impulse performance. Again, 96kHz and especially 384kHz sampled digital sounds “better than perfect”, another conundrum.
Think about bit depth and sample rate. Both are finite and limited to a set number of steps or samples, in a given time or for a given sample. Analog systems do not have any such resolution limitations. Vinyl, for example, allows an infinite number of possible volume levels, within the dynamic range of the medium.
Likewise, there is no sampling of waveforms in analog playback, hence high and low-frequency waveforms have the same amount of detail possible in them, with frequency limits determined by hardware and medium limitations, rather than compute power and data bandwidth.
Think for a moment about a high-frequency signal, like the sound of a cymbal being hit. This sound will have a range of harmonics and overtones that extend either side of the fundamental. Some of these harmonics will extend to over 20 kHz. Vinyl replay systems allow for the playback of frequencies over 20 kHz, whereas CD does not. This is due to the limitations imposed by the 44.1 K sample rate.
Where CD Loses
More importantly than the limitation in high-frequency response, the 44.1K sample rate means that a 20 kHz signal will be sampled approximately two times per waveform! If you look at the complex shapes and curves of a sine wave, for example, you will quickly see that no two points or samples on this waveform are going to allow you to accurately represent it during playback.
This is a fundamental and acknowledged limitation in the resolution of compact disc. This may also explain why most of the criticism of the Red Book format seems to be around high-frequency performance, hardness and glare.
There is no escaping that 16 bit 44.1K digital was the best they could roll out in 1982, for semi-sensible money. These days, however, 32 bit, 384 kHz digital is where we are at, in terms of playback. The problem is finding sources – recordings and masters – that have that amount of detail in them. They are virtually non-existent. Unless you have the analog master tape of course. Then you have a source with even higher resolution than 32 bit 384 kHz digital. See where this is heading..?
So, CD is technically less resolving of fine level detail and high frequencies than a good vinyl system. These inherent limitations mean it’s transient and phase performance are also technically inferior to the best analog systems, but herein lies another caveat. Vinyl is capable of superb technical performance in some areas, but has limitations in others.
Where Vinyl Loses
Typically pitch and speed accuracy of vinyl playback is an order of magnitude worse than CD. Turntables suffer from additive speed inaccuracies. This means that off-centre records and pitch issues with the mother and stamper vinyl are added to playback inaccuracies caused by the record player itself. These are very real problems.
Dynamic range of vinyl cannot compete, on paper at least, with that of compact disc. Vinyl offers a usable dynamic range – the difference between the softest and loudest sounds that can be accommodated within the medium – of around 70 dB. Compact disc offers a dynamic range of around 90 dB. The scale is logarithmic, so 20 dB more is not 20% more, it’s much, much more!
Compact disc also offers a technically flatter frequency response which is not subject to the resonances and wiring effects of magnetic cartridges of a turntable. There is also much less distortion, again on paper, than vinyl systems are capable of. The CD player itself theoretically introduces much less in the way of noise and distortion than a record player does.
Do I Hate CD..?
No, of course, I don’t. Actually, I love the format. For me, CD is the new vinyl. If you think after reading this that I have some vendetta against CD, then your ability to listen to rational arguments and evaluate data is way out. I’ve presented the strengths and weakness of both media and both are very viable media, moving forward.
AND YET, we have the curious situation where, given identical recordings, made from the same master, played back from vinyl and CD pressings from the same era, the vinyl recording very often sounds better. The conclusion one must reach is that, despite the shortfalls in dynamic range, pitch accuracy and distortion, vinyl’s inherent higher resolution is the key to this magic.