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Reducing glare in CD recordings

mosfet

Wammer
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Jul 20, 2005
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Richard
Something I’ve been experimenting with recently with good results for a number of CD recordings. The following is taken from an article printed in Glass Audio (5/97) and available as a PDF download from transformer manufacturer Plitron.

Research by Kirk[7] has shown that after an adaptation period, restricted high-frequency sound reproduction is preferred over full-range reproduction.

The recordings with an effective bandwidth up to 16kHz sounded very natural and true. Recordings up to 24kHz made me, my wife, and my friends ask what was wrong with the amplifier and the speakers.

You really need to read the entire article to put these comments into proper context – the article deals primarily with the design of output transformers for tube amplifiers and their effect on audio reproduction. Also some interesting stuff about extended bandwidth recordings using high sampling rates (super-tweeter users take note).

I’ve just cherry picked the two comments above as an explanation for the following.

Using an audio editor (Audacity) I applied low-pass filtering at 15kHz to a few tracks I’ve always found a little harsh sounding. Listening immediately, these recordings did appear to lose some degree of clarity as a result.

However switching between the original WAV file and the low-pass filtered WAV file a number of times I did find myself preferring the latter. Less glare and more natural.

This is something that can be tried for free if anyone else is interested (and applied to complete albums if wanted). I’ll post a step-by-step if needed, just ask.

 

peter312

Wammer
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Dec 29, 2005
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Peter
HiFi Trade?
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Hi Mosfet

Did you apply a "brick wall" filter or something a little more gentle?

I'm trying to remember: before CD (late 70's), didn't a lot of Hi-fi equipment have frequency ranges up to 15khz, 16khz and the like?

cheers

Peter

 

mosfet

Wammer
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Jul 20, 2005
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I’m not sure if the low and high pass filtering in Audacity is brick wall Peter. Certainly this is possible in the digital domain. There’s no option to specify the filter slope or rate of attenuation outside the pass band only the filter corner (or cut-off) frequency. Looking at the before and after frequency plot for the original WAV and low-pass filtered WAV suggests the slope is fairly gentle however. One for the Audacity forum I think!

I'm trying to remember: before CD (late 70's), didn't a lot of Hi-fi equipment have frequency ranges up to 15khz, 16khz and the like?
Compact cassette tended to have a somewhat curtailed frequency response to around 18kHz, depending much on the quality of the deck used and the type of tape formulation. Analogue FM radio broadcasts are also bandwidth limited to 15kHz.

The Glass Audio article I linked to comments on the sound of tube amp designs without negative feedback that are bandwidth limited to around 16kHz. It’s suggested much of their sound is attributable to this - with the region of 16kHz to 24kHz responsible for “harsh components†in audio recordings.

I’m also aware of a number of Sony ES CD players that had switchable digital filters to provide progressive amounts of high frequency roll-off.

 

meninblack

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zanash wrote:

You can achieve similar results with a green pen....on the inside and outside edges of the cd.
:djermaica:
rofl.gif.57a0859802223cfb25763a5f876a4be6.gif


 

zanash

Wammer
Wammer
Feb 21, 2006
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I'm sorry if your system doesn't provide you with the level of resolution that mine does......

This a repeatable experiment I have two discs of the same album one treated one not. Most people can hear the difference, and several people who were sceptics are now firm green pen users. Of course you need to use the right green pen ie a stop light or an opaque green poster paint marker work best but steadler permanent ohp pens work well too.

So rather than make fun of a honest observation go out and try it ....you just might suprise yourself. Then again as an obvious naysayer you'll have a closed mind,

still its your loss not mine.

 

meninblack

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No need for Green pens here:I keep all my CD's in a chest freezer which is mounted on phase 11 mana and festooned with strips of Belt Foil. I've also written "Nice, good music" and drawn a smiley face on with one of PWB's special RED pens.

There is a difference between "having a closed mind" and "not being a gullible half-wit." The Green Pen thing started out as an Internet hoax (based on joke physics), then became an urban myth and is now a fully-fledged Audiophile Legend. It's quite remarkable that there are still people around who are daft enough to believe it. Very few in the Wigwam, it must be said.

 

zanash

Wammer
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Feb 21, 2006
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Ah...the naysayers are coming out the woodwork now.......

I was told this was a forum were diverse opinions were discussed ?

I bet you don't even think cables can make a difference to the sound of your gear !

As I said your loss not mine...!

 

meninblack

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zanash wrote:

Ah...the naysayers are coming out the woodwork now.......I was told this was a forum were diverse opinions were discussed ?

I bet you don't even think cables can make a difference to the sound of your gear !

As I said your loss not mine...!
You haven't met the naysayers yet zanash! We are the sensible moderates.
biggrin.png


Go and post about green pens or mana in the main forum rather than the sleepy DIY corner and you'll be introduced to some of the, er, more forthright posters.

Most opinions are tolerated here in the tent, but start questioning peoples hearing or quality of equipment because they don't agree with yours and you can expect a little robust discussion.
biggrin.png
This kind ofunthinking snobbery may be the done thing on stinkfish or zerofun, but not here.

 

zanash

Wammer
Wammer
Feb 21, 2006
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Meninblack ...send me your address I'll post you a pen that does the biz.

So you have tried it haven't you ?

You may also find that stoplight pens sold for many years in the UK, where Trading Standards take a keen interest in hoax or misleading products. I sincerly doubt that the stop light pen at £19.99 a throw would rapidly of made itself known to them.

Are you naysaying because you feel thats what you should do as a herd leader [thats sheep].

You also need to be aware that I never post comments that can't be backed up by using those precious things on the sides of your head.

So if you would like a demo pm me

 

zanash

Wammer
Wammer
Feb 21, 2006
161
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0
, , United Kingdom
Quote " I'm sorry your system doesn't..........etc"

is a commiseration, with the other contributer.

I have not poked fun at anyone or used silly graffics, that I have left to you and the other contributers.

In actual fact its the other posts that are dissing me

 

meninblack

Wammer Plus
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Zanash, there are loads of hoax and misleading products on the market.

Religion, most cosmetics, all homeopathic anda lot ofother "alternative" health products, horoscopes, books on how to win the lottery, the list goes on and on.

I haven't tried those either. It's a mistake to believe that just because something is well established commercially it must have merit. Look how many people bought the James C**t album.
shock.gif.7732780fe7e208b945ce79ca96402fca.gif


I shouldn't think £20 felt pens sold to a tiny number of people are very high on Trading Standards hit-list, TBH.

 

zanash

Wammer
Wammer
Feb 21, 2006
161
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, , United Kingdom
I rest my case .....

the quote "the only unthinking snobbery around here " has not been offer by me.

Why are you maligning other forums, do you have a problem with loss of patronage ?

I even offer to send you one to try ..but no a closed mind.

As previously stated.....

Your loss not mine.

 
M

Mr Coherent

Guest
I can seriously reduce glare on cd's and produce a far more natural sound too, all by shinning a light on it
shock.gif.7732780fe7e208b945ce79ca96402fca.gif


Que Mosfet & MIB discuss please.............

 
G

Guest

Guest
Mr Coherent wrote:

I can seriously reduce glare on cd's and produce a far more natural sound too, all by shinning a light on it
shock.gif.7732780fe7e208b945ce79ca96402fca.gif
Que Mosfet & MIB discuss please.............
That light wouldn't be from alaser inside an Esoteric by any chance.?

 
M

Mr Coherent

Guest
Not a trick question Danny, Though the X-01 is rather special at that, however it can't turn a bad recording into a good one. No matter what people claim.

No, I'm talking an external source. I've demonstrated the 'lightmaster' to maybe 5 wigwammers in their own system as well as mine. Sorta works well
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Picard

Wammer
Wammer
Aug 1, 2005
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London
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Mr Coherent wrote:

Not a trick question Danny, Though the X-01 is rather special at that, however it can't turn a bad recording into a good one. No matter what people claim.No, I'm talking an external source. I've demonstrated the 'lightmaster' to maybe 5 wigwammers in their own system as well as mine. Sorta works well
biggrin.png
i have seen the light, hallelujah! :gag:

 
G

Guest

Guest
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[/align]

:Not Sure:Ok its a wild stab in the dark. I'm not even close am i:Upset:

 

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