Music from PC compaired to CD ?

Sastusbulbas

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There was a discusion in here recently about how PC's are going to replace CD players, with many believing a PC offers superior playback and information retrieval compaired to a CD player.

What I am wondering is, if items such as lossless audio (FLAC) on average compress a typical CD from 700mb to 400mb, and in terms of bit rate, reduce the CD from 1411kbps to 850kpbs then is this not in itself a reduction in CD quality ?

It seems that the term lossless audio is a little missleading ? What other software do people use to burn their CD's to hard drive ?

 

ob1

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In cooking if you use half fat cream and half fat butter it will not taste even half as good as The Real Thing!. I use nero (the most common software) to burn my cd but in wave form only.

 

meninblack

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Lossless removes only silences, unlike lossy compression which removes (allegedly) "masked" sounds.

We did some blind testing here and on HFC a while ago, and no-one could tell FLAC from WAV once they had been burned back to red book format.

 

jon

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Sastusbulbas wrote:

There was a discusion in here recently about how PC's are going to replace CD players, with many believing a PC offers superior playback and information retrieval compaired to a CD player.What I am wondering is, if items such as lossless audio (FLAC) on average compress a typical CD from 700mb to 400mb, and in terms of bit rate, reduce the CD from 1411kbps to 850kpbs then is this not in itself a reduction in CD quality ?

It seems that the term lossless audio is a little missleading ? What other software do people use to burn their CD's to hard drive ?
This is lossless compression because - when uncompressed - the compressed file is the same as the uncompressed file. You can rip a CD using Exact Audio Copy, which is free and can give measurably (though not necessarily audible) better than s/w like NERO.

If you're curious about whether lossless compression impacts on the sound, download foobar and rip the same track to both Flac and .wav with Exact Audio Copy. Foobar will then allow you to do a blind ABX test. Do this, say, 100 times - you shouldn't be able to hear the difference.

 

doctorjuggles

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Lossless compression is exactly that. Lossless. There is no difference between lossless and the wav file. How this hooks up to your stereo is another matter for debate, but the file itself is indistinguishable from the original.

ob1971, I'm not sure what the cream analogy is, but it's not relevant here.

 

Sastusbulbas

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So how important is that drop from 1411kbps to 850kbps of bit rate level ? the reduction by lossless compression by the likes of Flac ?

Surely some loss in quality must occur as some compression and bit rate loss occurs ?

 

ob1

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doctorjuggles wrote:

Lossless compression is exactly that. Lossless. There is no difference between lossless and the wav file. How this hooks up to your stereo is another matter for debate, but the file itself is indistinguishable from the original.ob1971, I'm not sure what the cream analogy is, but it's not relevant here.
I take it we are talking about the same lossless file (apple's Mac) my analogy is if you compress wave file by a half, you must lost something. Iuse todownload music from internet and when i burn it back to wave or cda files they sound thinner! They seem to be midrange happy and not much else.....all imho.

 

jon

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If you download an MP3 from the net, and then burn it as a CD audio file, the information lost when it was compressed to MP3 will still be lost - so it may sound different to how a CD would have done.

If you compress a file to flac, no information is lost (just like, if you use WinZip to compress a Word document, no info is lost). If you're concerned about a loss of quality with flac, though, the easy solution is to do a blind test (foobar makes this easy). You could also compress a .wav file to flac then decompress it back to .wav - you'll find they're identical, and no info has been lost.

 

meninblack

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Honestly - try the blind test. Even some folk with very high-end systems couldn't tell lossless from wav files.

You have to burn back to CD though, because artefacts of on-the-fly decompression are more easily audible.

Some folk with more middling kit couldn't tell high-bitrate mp3 from wav either. In sighted testing, there is a real "snobbery" effect IMO.

Obviously with downloaded files the quality of the original CD rip is a big factor. For best results, use a multi-pass ripper such as EAC.

 

Sastusbulbas

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Is there any software that does not lose any of the bitrate, and will allow full playback at 1411kbps or am I missing something here.

Sorry but dropping 561kbps of bit rate must compromise something ?

And does dropping 300mb of data not mean losing some of what you want to be lossless ?

Can you copy at full MB data with full kbps playback without any loss or compression whatsoever ?

 

meninblack

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Sastusbulbas wrote:

Is there any software that does not lose any of the bitrate, and will allow full playback at 1411kbps or am I missing something here.Sorry but dropping 561kbps of bit rate must compromise something ?
What do you mean? Playback software just plays whats in the file, I don't understand the remark about "losing bitrate"
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As I've tried to say, lossless compression only loses silences. An example: 100 consecutive zeroes = 100 bytes, this is replaced by an instruction that says "insert 100 zeroes" in maybe 10 bytes. On decompression, the zeroes are put back in, exactly as the original.

 

doctorjuggles

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Right, here's the Wiki write-up on lossless compressions.

Problem is, it gets a bit techie. But I remember reading a good, layman's explanation of the general concept in a mag not too long ago that explained it nicely. It went along the lines of:

"While a lossy compression will use psycho-acoustic methods to recreate an approximation of the original sound, lossless compression instead uses clever mathematics to reduce the size while keeping the exact information. Let's assume a certain section of music could be represented in number. Now let's say a small passage of music starts at 0 and ends at 10, it could reasonably be assumed that the half way point would be 5. If so, the compressed file leaves the 5 because when it's recreated, it's rebuilt with the 5 in. If it's not five, then it just encodes the difference (so if it's 6, then it encodes +1) and in this way, a total of 4 is saved."

Now it's a basic concept and that's not what's actually going on, but you can see the concept itself far better with this explanation than with all the technical nonsense that's spat out on Wiki if you have no desire to learn everything there is to know about flac.

Hope I've explained this as well as the bloke in the mag did!

 

garyi

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I think where the post starter is getting confused is that the software used for playing back apple lossless (iTunes) and FLAC (many programmes) actaully uncompresses the file as it were.

As already exampled, a word document in ZIP format is half the size, someone might look at that file on a computer and say, 'Wow its half the size, half the info must be lost' But when uncompressed with the proper software it comes back to full.

Same with FLAC and other lossless files.

FYI if using apple equipment such as the express, all audio is sent over the airwaves as an Apple Lossless file, then decoded by the express before being passed onto your hifi. Its just an efficient way of shrinking audio.

 

gsrai

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I've converted all my CD's to FLAC and a recent test where I played the same song on CD and wireless squeezebox (plus external DAC) resulted in my good lady not being able to tell the difference between the flac file and the CD!

 

mosfet

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meninblack wrote:

As I've tried to say, lossless compression only loses silences. An example: 100 consecutive zeroes = 100 bytes, this is replaced by an instruction that says "insert 100 zeroes" in maybe 10 bytes. On decompression, the zeroes are put back in, exactly as the original.
Nicely explained MIB.

 

oldfogey

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Another example would be the score as read by a percussionist for a symphony where instead of lots of bars with nothing in, they have a bar count, say 32, where they count bars and wait until they're needed. There's lots more pages in the violin part or the master for the conductor!

Lossless compression in action.

 

Chumpy

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Depending on your belief-system/how much you love the insert-documentation in a commercial CD package, the PC version at a suitable bit-rate on any competent budget soudcard PC will be as good.

Psychologically, I prefer concentrating listening to commercial CDs etc played from competent stand-alone CDP when I am not doing 7000 other things on PC.

It is your choice (occasionally more expensive might be set up to be better for purchaser-listener).

 

George 47

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What the guys are saying on lossless files is correct but be careful with PC music as the quality of some sound cards is appalling.

Play with files with fancy machines (as studios do) and it is correct; start using cheap sound cards and a whole bunch of other variables come into play. In other words how does the file come out of the machine into the analogue domain?

As for using an ABX set up, with a cheap sound card (100 times
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), you get mediocre sound quality where you are lucky you can tell anything apart least of all a fairly subtle change.

I have heard a comparison of original disc sound (from a hard drive), SACD quality (24/192) and CD (16/44) and the differences were very audible with 16/44 the most compromised. (Tony Faulkner organised this so the source was good). This was using a very high quality set up with EAR amps and Quad speakers. Of course with 16/44 being perfect, and SACD super perfect what hope is there for FLAC or MP3?

Theory correct; practice??????
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