Tag: sound

How Sound is Created and Heard

This discussion begins with the creation of sound itself.  Everything in nature that creates a sound creates an analog sound, which also happens to be the only kind of sound that we can hear.  And don’t forget the importance of air because without air we have no sound.  It is the air pressure pulses in the form of vibrations that allow our ears to hear sound.

Only in a studio using digital sound synthesis being directly recorded into a digital recorder is a digital sound actually created(but not heard). Even then you cannot actually hear it until it is converted to an analog sound and reproduced via a speaker.

My Thoughts on Digital Vs. Analog Sound

The vinyl record is my preferred media for active listening to recordings made in the 1950s and into the 1980s.

As discussed earlier, analog recordings played back on vinyl records add a certain amount of their own “noise” to the listening experience.  Some of this noise is not desirable such as the tics and pops associated with a record that is no longer in mint condition.  But it also adds a certain “warmth” and “life” that is missing from CDs.

To help explain my opinions in that regard I have several analogies and examples:

Vintage Car

Listening to vinyl as opposed to a CD is like looking at the paint on your car before and after you wax it. Vinyl sounds like a fresh wax job looks. It didn’t change the basic color but it enriches it making it fuller and more vibrant and full of life.

Another way of describing the difference between the sound of vinyl and the sound of CDs is to describe it in terms of visible and non-visible light rays;

Ultraviolet light is not visible to the human eye, but if you place an ultraviolet filter in front of your eyes you can see the difference made by removing ultraviolet light. I think of CDs as possessing a filter that does not allow all of the “colors” of the audio spectrum to be heard.  Perhaps that is good, or perhaps it is bad, but it is different, and I prefer the full spectrum of sound that vinyl provides.

Here is one last way of describing the fuller, richer sound that vinyl provides;

The CD specification stops abruptly at 20,000 cycles per second (20 KHz) whereas vinyl can reach all the way up to 45 KHz and beyond. Sounds above 20 KHz are simply not present on a CD which is OK in itself since it is above the hearing range that most humans can hear.  But that does not mean that the sounds above 20 KHz do not affect the sounds that are within the audible range. These higher tones can reflect tones back into the audible range.  This has the effect of enriching the sound that we can hear.

An imperfect analogy is to take a pure 440 Hz tone and compare it to its equivalent primary pitch on a piano which is referred to as A-440 (A below middle C). A pure tone of 440 Hz is dull and lifeless. The same fundamental tone on a piano causes many other “sympathetic” tones to be heard and for harmonics of the 440 Hz string to be amplified or augmented by other strings on the piano. So these inaudible pure tones above 20 KHz that are present on a vinyl record do have an effect on what you hear when playing back a vinyl record by affecting or generating tones that are audible.

One last augmentation should be mentioned and that is the sound that you hear when playing music back through a tube based preamp and amplifier when compared to transistor based amplifiers. Again, it adds “color” to the sound which you either like or not, but I do.

That’s my story and I am sticking to it.

Reducing Unwanted Noise

Bomb Shelter

Phono CartridgeThe phono cartridge contributes to unwanted noise as well. It is a sound transducer and can be thought of as a specialized type of microphone in that it picks up the vibrations from the stylus as it tracks the record groove and responds to its encoded vibrations.

Unfortunately it can also transmit the vibrations from any noise that it picks up.  This includes your footsteps on a wooden floor or any noise including your voice!  You can actually record your voice by talking very loudly and very closely to the phono cartridge.

That’s Not a Scratch on Your Vinyl – It’s Dirt!

Dirt and static electricity may cause good records to sound “scratchy”. A proper cleaning will remove dirt and static electricity from the vinyl. You may be very surprised to hear how good your records sound once cleaned.  What you thought was noise caused by scratches may disappear.

An old or worn stylus will cause your records to sound bad or sound scratchy. This is because a worn stylus is getting down to the bottom of the record groove where there is no music. Understand that a stylus begins life shaped like an ellipse (rounded) and then wears down to a point and falls further down into the groove until it hits bottom.  This is bad for your records. The music resides on the sides of the record groove and is where a new stylus (needle) sits while playing.

Illustration of Wear and Tear from the Stylus