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Subject: Re: AW: Question about CD-Quality and MP3

Re: AW: Question about CD-Quality and MP3

From: Bluechip <csbluechip_at_gmail.com>
Date: 2006-01-31

At 02:23 02/02/2006, you wrote:
>To many years in front of a Hi-hat eh? I sure knows what that's all about
>dude. My right ear has lost about 20% of the highs. I used to play a Tama
>Imperial Star kit using Quantum 3000's with no ear protection. I'm still
>using the Quantum's but I have a real kit now. And ear protection all the
>way man. Don't want to become a member of the deaf blind community. LOL!

LOL!

I can whole heartedly recommend the etymoic ear-plugs - they claim a flat
response - but as sound is perceived by more than the ear (especially with
a KW or 2 of fold-back aimed at your head) the flat response is not really
likely. They are however, inconspicuous to the degree that people looking
into your ear and shouting requests fail to realise why you can't hear them
(repeatedly). They can be "screwed in" like a volume control. They don't
disagree with sweat. They are so comfortable you could _live_ with them in
place.

What a shame I did not discover them until it was too late :(

One day I will have the cash to check out their headphones :)

>My hearing is still real sharp and I can definitely tell the diff between
>128 and 192. So, 160 is likely in-between that.
>
>I think you also need to consider the source as well. Everything from
>tracks to mixing to mastering will have varying levels of compression
>already applied. We recorded at a basement studio once where the guy
>applied so much compression that when we spun are stuff on a local INDI rock
>radio show the sound was brutal. FM radio applies even more compression.
>No 128 bit for that crap. Like Blue Chip says, experimentation.
>
>rocker
>
>
>rocker
> ----- Original Message -----
>From: "Bluechip" <csbluechip@gmail.com>
>To: "Rockbox" <rockbox@cool.haxx.se>
>Sent: Monday, January 30, 2006 5:57 PM
>Subject: Re: AW: Question about CD-Quality and MP3
>
>
>A friend of mine encoded the same (chosen to be complex) track and
>compressed it at everything from 128...320 ...It was his (non-musicians
>(and he knows that)) ear that said "at 160 I personally couldn't her the
>difference, so I went with 192 - the next one up."
>
>I am a musician - albeit with a hearing problem (too many years in front of
>a hi-hat) ...and my take is: I can tell the difference at 160 ...but I use
>my mp3 players 1) in the car, 2) as a walkman, and 3) background music at
>parties ...If I want to listen to CD quality I listen to a CD ...There is
>soooo much background noise in car/street/party that you're not going to
>hear errors in the compression (loss of treble, bass, patterns in the
>(psuedo)random-noise, hissing cybals etc.) ...So my CD collection has been
>compressed at "160/44.1/joint-stereo/quality=0 (highest)/optimise for
>quality"
>
>In honesty though mate, the only way to know the point where YOUR brain can
>identify the errors is by trying compressing one track at lots of speeds
>and sending yourself slightly mad listening to them over and over again.
>
>Best thing is get a friend to put them on the CD in a random order. Sit
>down, blindfolded and mark the tracks out of 10. Decide where how far from
>10 you are prepared to accept (given where and when you will listen to the
>jukebox). And the answer will be there in front of you.
>
>For a laugh put multiple copies of each bitrate on the CD ...include the
>original uncompressed version ...see if you give identical files different
>marks ...if you did - take the highest mark for any example. (Ie you give
>the 160 8/10 the first time around, and 6/10 the second time around
>...either you have sensitised your ear to the errors, or you are imagining
>things. If it's THAT close a call - then 8/10 it is!)
>
>BC
>
> >Hi Rob
> >
> >Thank your verry much for your detail infos. I have yet i hope a last
> >question:
> >On witch samplerating and hz you can't hear definitly the different between
> >a Sound on a CD and sound on an MP3-File?
> >Somebody thinks, that a compression with 224 kbps, 44100hz, VCR-Level 4
> >it's
> >sufficient to reach the CD-Quality.
> >
> >Some tests and knowhow can be verry interesting.
> >
> >Greetings
> >Selamet
> >
> > > -----Ursprüngliche Nachricht-----
> > > Von: rockbox-bounces@cool.haxx.se
> > > [mailto:rockbox-bounces@cool.haxx.se] Im Auftrag von rob powell
> > > Gesendet: Mittwoch, 1. Februar 2006 11:11
> > > An: Rockbox
> > > Betreff: RE: Question about CD-Quality and MP3
> > >
> > >
> > > Hi,
> > >
> > > Not sure I understand the question entirely, but here's some help.
> > > Hopefully it'll be of use to others too.
> > >
> > > These comments are obviously not all-encompassing, but they
> > > do to gain an
> > > understanding. There are 2 elements to the quality of a
> > > digital audio file,
> > > whether it be MP3, Ogg, or whatever. Sample frequency and bit rate.
> > >
> > > First, professionally produced audio CD's are always sampled at 48KHZ,
> > > whereas most MP3's and minidisks tend to be sampled at 44KHZ.
> > > Second is the
> > > bit-rate, not so critical as the sampling rate, but still
> > > important. Most
> > > MP3's are recorded at 128KBPS, (kilobits per second), though
> > > of course you
> > > can record at whatever value you want, provided your MP3
> > > player will support
> > > it). I for example record books at 48KBPS, 22K sampling
> > > rate, and mono.
> > >
> > > It's generally agreed however that to obtain CD quality, you
> > > need to be
> > > recording MP3's and any other audio format for that matter at
> > > 192KBPS. For
> > > reasons that I'll go on to explain, it's not actual CD
> > > quality, but it's
> > > recognised to be audibly very close, and barely noticeable.
> > >
> > > There are basically 2 types of digital audio formats, lossie
> > > and lossless.
> > > Lossless create larger files, lossie ones smaller. .MP3 .ogg
> > > and .wma are
> > > examples of lossie formats, .wav is a lossless format. The
> > > issue is not
> > > whether you loose anything by converting to MP3, but whether
> > > you'll notice
> > > what you loose on the equipment you're using for playback.
> > > 44KHZ and 128KBPS
> > > are generally recognised to provide an adequate level of playback for
> > > portable digital audio devices, and indeed I find that
> > > generally to be true:
> > > however when I connect the Archos or Iriver to my hifi
> > > system, I can hear
> > > the difference quite easily between the CD and the music on my player.
> > > Basically it's horses for courses.
> > >
> > > Inevitably however there's a trade-off between file size and
> > > quality. You
> > > don't actually need an audio book (speech) to be the same
> > > quality as your
> > > favourite album: so you can get away with lower bit-rates and sample
> > > frequencies, which mean smaller files, and less space on your
> > > MP3 player. I
> > > change the bit-rate and sample rate quite a bit, depending on what I'm
> > > recording. Old football matches recorded from AM don't need
> > > to be recorded
> > > at a high bit rate and sample frequency, as the bandwidth of
> > > AM limits the
> > > quality of the original. Well-recorded stereo radio dramas
> > > however benefit
> > > from higher recording quality.
> > >
> > > The generally accepted rule is, that the MP3 standard is good for many
> > > reasons, not least because all digital music players will
> > > play it. However
> > > Ogg Vorbis WMA and others have advantages. Ogg Vorbis files
> > > take up less
> > > space for the same sample and bit-rate size. It's also a more modern
> > > encoding standard, and therefore the quality of a file will
> > > be higher if an
> > > MP3 file and an Ogg Vorbis file of the same size are
> > > compared. However a
> > > .ogg file and an MP3 file recorded at the same bit-rate and
> > > the same sample
> > > rate will be of very similar quality. That's as I understand
> > > it, if I've
> > > got it wrong, I'm happy to take corrections: as I'm a bit hazy there.
> > >
> > > Gary, you might know more.
> > >
> > > I think that all the units that'll take rockbox are
> > > capable of reading
> > > files from 32 to 320KBPS, and with sample rates of 22 to 48KHZ.
> > >
> > > In short, the lower the bit rate and sample frequency, the
> > > smaller the file,
> > > but the poorer the playback quality.
> > >
> > > HTH,
> > >
> > > Rob
> > >
> > > -----Original Message-----
> > > From: rockbox-bounces@cool.haxx.se
> > > [mailto:rockbox-bounces@cool.haxx.se]On
> > > Behalf Of Selamet Aydogdu
> > > Sent: 01 February 2006 09:32
> > > To: rockbox@cool.haxx.se
> > > Subject: Question about CD-Quality and MP3
> > >
> > >
> > > Hello,
> > >
> > > I search some sources that describe the different about MP3
> > > and CD-Quality.
> > > If it's possible that you can hear the same sound in MP3,
> > > that exists too in
> > > CD-Quality? Whats about OGG?
> > >
> > > Greetings
> > > Selamet
> > >
> > >
> > > --
> > > No virus found in this incoming message.
> > > Checked by AVG Free Edition.
> > > Version: 7.1.375 / Virus Database: 267.14.25/247 - Release
> > > Date: 31/01/2006
> > >
> > > --
> > > No virus found in this outgoing message.
> > > Checked by AVG Free Edition.
> > > Version: 7.1.375 / Virus Database: 267.14.25/247 - Release
> > > Date: 31/01/2006
> > >
> > >
Received on Thu Feb 2 03:56:35 2006


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