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Wide bandwidth = necessary?

Hi folks, there is one paradigm that bothers me a bit: many experts and audiophiles are stating that Red Book technology is outdated because of it's bandwidth limited function. I've read the human ear is capable of perception of frequencies beyond the normal human hearing, up to 40kHz. But this is only with live music! When listening to recorded music there is a restricted bandwidth because many microphones can only pick up frequencies up to 20kHz. So why the need for more and more bandwidth with regard to digital sound reproduction technology? What is not present in the recording can't be heard either, even with very wide bandwidth music reproduction gear.
What is also laughable is that many vinyl adepts say that phono playback gear can reproduce tones as high as 40kHz and that is one of the reasons phono playback sounds more "natural" than digital playback. This is a bit of a contradictio in terminis because most LP's are very band limited (30Hz to 16kHz is quite common). Your comments please.

Chris
dazzdax
bombaywalla's avatar
bombaywalla
1,958 posts
 
Hi Al,
The main benefit of higher sample rates, which figures to be a very significant one, is that it allows for a gentler rolloff of the "anti-aliasing filter" that precedes the A/D converter in the RECORDING CHAIN.
Looks like I read your post too quickly & did not note the A/D part. My bad.
paulfolbrecht
603 posts
 
After trying them all, I like many people, have concluded that the best format for digital sound is redbook CD played back on a DAC with NO oversampling and NO digital or analog filtering - such as an Audio Note DAC! This bandwidth-limited solution gives digital sound that is truly as close to analog and as lifelike as is possible with any digital technology thus far.

Oversampling introduces non-musical artifacts into the signal. This is a fact. And the problems with filters of all types are well-known.
stefanl
296 posts
 
Here is a link to the main "formal" arguement about why wide bandwidth is necessary.For your health!http://jn.physiology.org/cgi/content/full/83/6/3548
dazzdax OP
599 posts
 
First of all I would like to thank all of you for the wonderful comments. The reason for this post was to get clarification from you the need for the ability to reproduce frequencies beyond human hearing.
In the past some manufacturers like Pioneer tried to "reconstruct" the signal content above 20kHz by using special filters like the "Legato Link". This was done because the designers believed that the frequencies above the 20kHz (up to 40kHz) were necessary for a natural sound. This is also one of the arguments of the vinyl people. But if the mics are capable only of picking up frequencies up to 20kHz, why the need for gear that can reproduce frequencies above that (if that is already bandlimited in the first place)? In case of vinyl: I truly believe cartridges are capable of reproducing frequencies above 20kHz, but if the vinyl itself contains no frequencies above let's say 16kHz at all, what is the use for such a bandwidth?

Chris
stefanl
296 posts
 
Well Dazzdax,I can refer you to an old Hi-Fi review (1982) of 5 cartridges by Martin Colloms who was in the lab testing those cartrides square wave responses out to 40Khz for his review,this is in the members section articles at The Vinyl Engine.I at one time hooked up my phono stage to my soundcard and using the old Cool Edit program recorded some Led Zepplin at 96/24 and there was ultrasonic content definitely present out to 40Khz.This was actually to duplicate an experiment by John Atkinson of Stereophile who did an article about the high resolution of vinyl (still in the archives).The Sheffield Direct to Disk series used to advertise how their recordings captured sonic information out to 50Khz.
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