Have you ever considered what a numbers game the HI FI industry has become? Sound engineering has come on in leaps and bounds in the last 50 years. We now have consumer products which are far in advance of the record players we were using in the 1960s. We have now hit the point where improvements to stereo sound are really coming under the law of diminishing returns.
Take the turn table, cartridge and stylus industry for an example. During the 1970s belt driven turn tables became popular; they replaced rim or idler drive record players as a consumer product. They almost eliminated deck rumble.
Moving Magnet cartridges and their Moving Coil cousins replaced ceramic cartridges to completely improve frequency response.
Diamond styluses replaced sapphire ones to improve the longevity and frequency performance of the turntable cartridge.
Electronic speed control almost eliminated wow and flutter speed variations.
Even the most humble deck has all these features nowadays. So where do improvements come from? They are difficult to come by.
The human ear when perfect and under ideal conditions can hear frequencies from about 20 hz to 20 khz. But from the age of about 8 or 9 the ability to hear higher frequencies declines, so that many men above the age of 70 can no longer hear frequencies above 8 khz. Women's hearing fails more slowly. Most adult men cannot hear frequencies above 15khz.
Stylus manufactures are now making elliptical styluses which can reproduce sound frequencies up to 55 khz. You may ask why bother to make them and why bother to buy them when most adults cannot hear sounds above about 15 or 16 khz? It is part of a numbers game.
The top C note on a grand piano is 4.186khz and middle C is 261.6 hz. Top C is rarely played but when it is there are harmonics which are of a higher frequency but you may want to consider why there is a need to reproduce sounds above 16 khz when most people cannot hear them.
The maximum frequency which can be played on FM radio in the UK is 15 khz. No-one ever complains about this.
A soprano uses primary frequencies in the range of 250 to 1500 hz but can produce harmonics in the range of 3,000 to 4000 hz. You may be wondering again why we need to reproduce frequencies far higher than the human voice can sing. We don't, but of course it is desirable to have some redundancy built into the system.
This is why when sound engineers designed the CD audio system they did it to cater for a frequency response of 20 hz to 22khz. This is far beyond the range of most musical instruments and the ability of our ears to hear or perceive such high or low frequencies.
They also designed the CD to have a dynamic range of about 96 decibels, which is far beyond the range of an orchestra from its softest sound to its loudest sound. Pop records rarely exceed a dynamic range of 20 decibels which is far narrower than the dynamic range of an orchestra which can be up to 80 decibels.
LPs can reproduce a similar frequency range as CDs but their dynamic range is nowhere near as wide but even so an LP is good enough for most peoples ears. So they can easily compete in the numbers game.
HIRES music is completely redundant and unnecessary. A 24 bit 192 khz digital resolution file can provide a dynamic range of about 144 decibels, and if you add this to the noise floor in your living room which is about 40 decibels you would be able to reproduce the sound of the space shuttle taking off in your living room, but only if your sound equipment was strong enough. This is ridiculous.
192 khz digital files can reproduce frequencies up to 96 khz; not even your cat can hear this high but of course a bat can. So your 24 bit 192 khz HIRES file can knock bats out of the sky 20 miles away if your amp and speakers were powerful enough - but they never will be. This is a preposterous musical proposition and a preposterous and absurd numbers game.
At normal and safe listening levels no one has been proven by scientific testing to hear the difference between CD quality and HIRES listening quality when all other parameters are equal. HIRES is completely redundant technology.
Technology has brought us to the point where the potential performance of the equipment is much greater than the actual performance of our ears and our hearing perception. We have been at this point since the invention of the CD.
Do not be fooled by so called sonic improvements as part of a numbers game unless you want to waste prodigious sums of money.
http://www.scientificamerican.com/article.cfm?id=expert-opera-singer
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