03.22.02
CD/Ear Tweaking
2002, March 22nd
This tirade is partially in response to this article and others like it. I hesitated to give this idiot the link, but some of my more vitriolic statements make more sense after you have read his comments.
Much to-do has been made in high-end audio magazines about the effectiveness of various tweaks that the audiophile can perform. The theories behind these tweaks and their originations are more often than not lost in the mists of time. Some probably originated with the vinyl record. Some may have been April fools jokes that turned ugly. In any case, I am writing this in the hope that somehow, somewhere one person will read it and get over themselves enough to think about what possible effect these tweaks might have and stop trying to perpetuate myths.
First I will address some real live honest-to-gods tweaks that may have some effect. These all have to do with vinyl records. Records work because the wave form of the sound to be reproduced is carved into a little groove. As the record spins, this groove causes a tiny crystal to expand and contract. This causes a high-voltage (but very low current) signal on a pair of wires. This wave form should have a shape that is similar (hopefully very close to identical) to the original sound recorded.
Stereo records add the second channel by carving each side of the groove at right angles to one another. This allows each side of the groove to carry one channel. The crystal then has two independent signals across each of two pairs of faces. OK, this was oversimplified, but there is important information in there.
Records suffer from many problems that can cause the signal on the crystal to differ from the signal that was recorded. Scratches in the surface of the record and foreign materials in the groove can cause pops or clicks in the sound. Static on the vinyl can cause crackles as it discharges through the needle. The friction between the needle and the vinyl adds hiss and channel cross-talk. Vibrations caused by the spinning of the platter add a variety of distortions and extra sounds. Variations in the force of the needle on the vinyl can cause distortions and volume changes. Even the lateral force of the needle as it moves from the outer edge to the inner edge of the record can make a huge difference in the sound of a track.
Over the years, audiophiles have developed various techniques to combat these effects. Pads added to the platter reduce mechanical hum. Changes to and adjustments on the tone arm (the swinging part that holds the cartridge that holds the needle) improve channel bias and sound changes caused by location. Solvents and brushes were developed to clean inside the groove. Anti-static guns help to reduce the crackles caused by excessive electron build-up. Some have even added oils and other liquids to the surface of the record to reduce friction.
Some of these changes are “approved” by the recording industry. Others are discouraged as they can damage the record itself. Since vinyl records are all but dead, I won’t go into specifics. Check with your industry rep before trying any of the above or be prepared to buy a new copy of your record or even a new turn-table.
CDs, in contrast to vinyl albums, suffer from none of the problems above. CDs are a digital medium. What this implies is that the signal coming off of the CD is a wave that represents a series of numbers. These numbers represent the wave forms of the left and right channels of sound. These numbers include, in addition to sound information, error correction information (also numbers) that allow the player to detect when a read error occurs and how to handle that error based on severity. In some cases, an error in the read is corrected. In others it is not correctable and the CD player will compensate. The price of the player will (to a certain degree) determine how it compensates.
The important thing to note is that the waveform coming off of the CD does not represent the sound that will be reproduced. Subtle changes in the amplitude or characteristics of this wave will have no effect on the sound that comes out of your speakers. These changes might reduce (or increase!) the number of errors that the player must handle, but it cannot sound richer, have better spatial separation or improve the sound response in bass, mid-range or treble. As Chief Engineer Scott would say, “You canna change the laws of physics.”
So, stop sanding the edges of your CDs. Stop painting their edges or their inner surfaces. Stop glueing dampening mats to them. Stop drawing on the upper, or lower surface. Stop degaussing and anti-staticing them. These changes (tweaks) will have no effect. Don’t believe me? Set up a double-blind sound test and really test your assertion that these things will have an effect.
Still don’t believe me? Then let me suggest that for the ultimate listening experience, if you are tweaking the sound producer, you must admit that the listener can be tweaked as well. Let me suggest the following:
- Paint the inner surface of your ears with a green marker to produce a more evenly colored sound. (Reduces pink noise.)
- Wrap yourself in foam rubber so that you are acoustically neutral.
- Stand on a multi-layer pad of particle board and acoustic tile (at least 5 layers of each) to get acoustic separation from the floor.
- Remove the wax and hair from inside your ears with a 20% solution of acetic acid to reduce sound constriction and reflections.
- Break-in your ears each day by banging two pot lids together 20 times immediately next to each ear.
- Soak yourself in mineral oil to reduce crackling.
- Carefully drill 5 equally spaced holes with a 1/8″ bit just through your skull on your forehead to improve spatial perception.
- Finally, your body produces many sounds (heartbeats, bowel sounds, etc.) which your brain must filter out. These can diminish the listening experience. It would be best if you could stop these sounds entirely or acoustically separate your head from them. Consume a large quantity of arsenic or decapitate yourself just before listening to any of your CDs for the ultimate in sound reproduction.
Thank you for your attention.