Vinyl Records

Vinyl has become trendy again, and record pressing plants are pumping out as many new records as the plants can produce.  Some plants are even expanding.

Vinyl records have a mythology around them promulgated by audiophiles.  It is said that they are analog (they are), and thus more accurately reproduce the original audio than the digital “stair steps” (they don’t), and that, somehow music heard via vinyl is “purer” than digital music.  Almost exactly the opposite is true.

I hate to break it to you, but vinyl is a terrible medium for reproducing audio, and its various deficiencies require countermeasures that significantly change the audio.  Tom Scholz, the leader/recording engineer for the rock group Boston, supposedly tried to get the first Boston album recalled when he heard what his mixes sounded like on vinyl.  Tom Scholz’s experience aside, many of the countermeasures make changes to the audio that audiences can find pleasing.

These countermeasures were implemented in the process of “mastering”.  Originally, mastering was just creating a master disk, from which the pressing plates for the vinyl records would be made.  The mastering setup was simply a cutting lathe that created the sound groove in a metal plate.

One of the physical properties of a vinyl record is that the width of the groove is determined by the volume of bass frequencies.  When music started being recorded with electric bass, mastering engineers found they could often only get five or ten minutes of audio per side of a long-playing record, instead of the normal 15-20 minutes, because the grooves were too wide.  This resulted in them adding devices to the mastering setup to do compression and limiting on the bass frequencies.  The same measures are required for classical music with lots of tympani and/or low brass, and jazz with a prominent bass part.

Another issue with vinyl is that it does not reproduce high frequencies well, and midrange frequencies tend to be prominent.  Mastering engineers added equalization to their mastering setups to partially compensate, and recording engineers would often boost high frequencies in their mixes to help them be audible on the record.  Even with these measures, high frequencies on records gradually disappear toward the top of our hearing range.

The dynamic range of vinyl–the range in loudness from the quiet background hiss of the record to the loudest sound it can produce–is much smaller than that of our ears.  On vinyl it is about 70-80 db, while our ears have a range of about 120 dB.  Every 3 dB represents a doubling in loudness, so the extra range can be pretty important.  For music that goes from being quiet to very loud, it can exceed vinyl’s limits, so the quiet parts are buried in the background hiss.  To deal with this issue, vinyl mastering engineers compress the entire mix (as well as adding extra compression and limiting for the bass frequencies), which reduces the dynamic range.  This technique is used on all types of music, but it is most important on classical recordings because they often have wider dynamic ranges.

There are other, more arcane, measures taken in mastering, but many listeners find the ones I’ve described add a quality pleasing to the ear.  Overall compression makes it easier to hear all the parts, bass compression often makes the bass sound better, and the rolling off of high frequencies results in a sound many describe as “smooth” or “warm”.

At least part of the blame for the vinyl mythology has to do with a shortcut record companies took.  When Compact Discs first came out, the record companies believed that they didn’t need to do any mastering for digital because digital didn’t have vinyl’s limitations.  They sent the master tapes to CD manufacturers with no mastering, and the CDs that were produced did not sound anywhere near as good as vinyl.  They didn’t have any compression (or only what the recording engineer used), and because the high frequencies were boosted for vinyl, they sounded “harsh” or “tinny”.

These problems were caused by a lack of mastering, not, as audiophiles believed, an inherent flaw in digital audio technology.  It took a few years for the record companies and engineers to figure out that, in order to sound good, a similar mastering process was required for digital media.  CDs manufactured in the early 1980s often have these sonic problems, while later “remastered” versions mostly sound better (to my ears) than the vinyl, or at least more similar to the original master tape.

Today, great tools exist for mastering digital recordings, and pretty much every digital recording, whatever medium, gets mastered.  Mastering engineers have built on the vinyl techniques to create a large bag of tricks that make recordings sound better to listeners.  Over time, the ears of audiences have adjusted to being able to hear high frequencies without cringing, so they accept recordings where you can hear what the cymbals really sound like.  As a friend of mine who is a mastering engineer said to me yesterday, even an mp3, if it has a reasonable bit rate, will sound much closer to the original than vinyl will.

If you love the sound of vinyl, please enjoy it with my blessing.  Apart from the sonic aspects, I find the 15-20 minute album side a more satisfying chunk to listen to than a 3-minute mp3.  Just let go of the idea you are hearing what the recording engineer heard when he was mixing.

Now that I’ve rained pretty hard on the vinyl parade, do I have an alternative?  Is there a different technology that I think will serve listeners even better?  Stay tuned for Giving Good Audio for Music Part II: 24-bit Audio.

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