Some Ideas on Recorded Sound 


last updated 2/10/2013
D Vautier

What is Recorded Music ?

Imagine Edison catching musical notes out of the air.  What a deal.

Recorded music does this.  It is the preservation and reproduction of air waves that are generated by some artist or instrument.  How well the sound gets preserved depends on the quality of the transducer devices involved and the way the sound is captured.  A transducer is any mechanical/electronic device that can take airwaves and convert them, in this case, into electronic pulses that correspond in amplitude and frequency to the actual air waves themselves.  The electronic signals are converted into some kind of physical media and stored on a device, Later the physical media is inputted into another transducer device that attempts to reproduce the sound wave as close as possible.  How close?  Depends?  Just how well the sound is reproduced depends on all of these transducer and storage devices and how well they are built.  When you really think about it, our ears are the most basic transducer, in fact the only ones that really matter.

Over the years the preservation and reproduction of sound has gotten a lot better and so have our expectations.  Sound started out being saved on wax or tinfoil, then on a wire, then cut into shellac cylinders and disks or on a cellulite tape, then a mylar tape, and finally converted to binary code on digital devices.

Initially sound reproduction was considered great but by today's standards it was really really bad.  So as the novelty wore off we demanded greater and greater sound quality and gradually we got it.  We also demanded transportability and control and we got that too.

Analog vs. Digital

Any discussion of one or the other music formats is not at all an issue in this discussion--there's no such thing as a digital or analog type of music.  They are just simply different ways to store music.  Everything that's any good to our ears is really analog -- period.  Digital is a way to store analog and as such is excellent because it can be copied forever without loss or it is "lossless".  In the old days we stored in analog.  Analog storage could lose information with every copy or generation.  Data storage of any kind is subject to degradation due to age, environment, and use.  The real issue is sound quality, which is also a moot argument since anything you heard is analog to begin with (and end with).  That's the way speakers work and the way ears work so in the last analysis it's all analog.  Digital is just a way to represent analog, and a very efficient, convenient, inexpensive way to keep sound.  When played it is converted from a digital series of bits to an analog signal of fluctuating strength and then run into a transducer device like a speaker that pushes air back and forth so it can effect your ear drums just the way voices, cellos, and violins do to begin with.  When you digitize a record, you are using a physical storage media, a record or tape or CD, to generate analog electronic signals that run through a digital conversion program or codec, and stores it in digital format so it can be later converted back to analog electronic waves that then effect magnets that move diaphragms that move air and recreate the same music for the ear it started out with.  Music can therefore be listened to over and over without damage or deterioration, and can be copied over and over again also without degradation or signal loss.

 

 

Vinyl Records

Early record companies recorded music on wax with a needle.  Later on they used small cutter blades to cut a signal into soft metal masters and this corresponded to the sound wave.  After a while engineers began using high quality analog tape.  The music was reproduced to vinyl records.  The master tapes converted magnetic signals to a cuter blade that inscribed lots of little wiggles on a surface, first shellac later mylar, a very fine type of rubber.  The record could be played to produce an analog signal, and by the way, sometimes a very good signal if you have good equipment.  LP records are a good media because they can be stored a long time, but every time they are played, some of the little wiggles could get damaged.  With good equipment the damage is less but the record will eventually lose some quality.  If you play a record once and obtain a good digital signal, you can play the digital media over and over without any quality loss, and still have the original record.

Early vinyl LP records weigh about 200 grams and did not bend.  By about 1970 the later LPs were around 90 grams or so, thinner and quite flexible and used a finer quality of vinyl.  I find that the lighter and thinner vinyl records tend to sound much better.  It makes sense.  The rubber is superior quality and can produce more intricate and tighter wiggles.  But then the lighter LP is more subject to warping.  

 

Is Digital better?

Of course digital is better than analog as a storage media.  But lots of audiophiles claim records sound better and they could be right.  From my own experience, there is no difference between a played record and it's exact digital copy as long as the equipment is good enough and the degree of precision in the digital capture is good.  But I can always tell when a record is played directly because on quiet passages there is always some background noise.  

 

WAV vs. MP3

These are sound file storage formats like languages.  What's the issue here?  I started out with wav format and I was quite pleased with it.  But after some time I had so much music that it became difficult to keep it documented.  I switched to MP3 which allows documentation; title, artist, album, genre, etc, plus it's a lot smaller in storage size.  If you look closely at the wave form of mp3 compared to the same wav, you can see that the wav contains much more granularity.  MP3 is called lossy, which means that if you edit and save it a few times it will begin to lose sound quality.  If you just capture music and do cosmetic editing then MP3 is fine.