With more people nowadays downloading music from such as iTunes, I wondered if there was any noticable difference in sound quality to a song on a CD to the same song downloaded?

Does anyone know if this is true in any way?

Yes its true, digital downloads uses lossy compression techniques which removes some information from the original wave files.

There are various bit rates used, the lower the bit rate the less the quality. At the higher bit rates you won't notice much difference.

On a Hi-Fi you can certainly tell the difference between the CD and even a 320Kb/s MP3.

But can you reliably tell which is which in double blind tests?.

i think i could. I can hear the difference between MP3 via direct AUX IN and original CD in the car too - and thats only the basic unit from the factory with original speakers.

Apart from a few problem signals which mp3 struggles to encode cleanly, no.

Extremely few people can. Most who say they can, haven't done the test properly (or at all).

This test was not without its faults, but it's interesting because so many self-proclaimed "golden ears" took part...
http://archimago.blogspot.co.uk/2013...test_3422.html

Rigorous listening tests (none of them at very high bitrates)...
http://wiki.hydrogenaudio.org/index....istening_Tests

Official mp2/mp3/AAC listening test:
http://www.mp3-tech.org/programmer/docs/w2006.zip

Cheers,
David.

Yes but when playing this you know the source. Could you tell the difference in a double blind test?

Dont ever think downloaded music especially classical will ever sound like a CD Pop music might be ok because of the way they are recorded but if it quality you want stick with cds

As a one time audiophile I am not too proud to admit that I am now of an age where it is very difficult for my ears to discriminate between downloads and CDs, for the vast majority of my listening (including some orchestral classical music) downloads will suffice!

Pop music is mastered so terribly its academic as to whether the sound quality differs much between uncompressed WAV (CD) and a medium bitrate MP3

Personally I can't tell the difference between 256k Mp3 and WAV, that's with pretty decent equipment and even if I could I'd have be really, really concentrating.

I haven't done a blind test cos there's only me here, and I'd be knocking into the furniture, but on certain tracks I can certainly tell the difference.
Having said that I mostly listen to MP3s nowadays, even on my Hi-Fis, just for the convenience.

For instance, a song I always think tests a Hi-Fi is 'Close to the Edge' by Yes, cos it's got very high pitched tweety stuff and very clear bass. Definitely sounds better on CD. But I admit the difference is not huge.

However there's nothing to stop me ripping my CDs again in some lossless format in the future, though whether I'll be bothered is another matter.
Can't do that with bought MP3s though.

It's in the car on an SD card

As is Starship Trooper, and a couple more Yes tracks.

Well there you go. You can't be all bad?

I've been a Yes fan for a LONG time - I even saw them once at Stoke Football Ground, although their set was cut short due to rain.

I still buy CDs because I feel that I own it which I wouldn't feel with downloads. Then I rip the cd onto my pc in lossless WMA because I wanted lossless and I was using Windows Media Player as my playback method on the pc.
I then discovered that whilst most mp3 players will also play WMA files, rarely do they recognise the lossless version. So, I ended up copying my favourite tracks into mp3 as well.
I am prepared to concede that my deteriorating ears might not hear the difference, particularly in a car environment but, as with camera pictures, you can copy to a downgraded standard but you can't go the other way.

Let's imagine that I have just handed you an Orange. I tell you that a technique has been used which has removed 80% of the Orange in a way which is completely undetectable. Is that an attractive idea to you?

Why on earth would I wan't to take part in a blind test to hear conclusions that do not benefit me in any way? When I listen to music at CD bitrate (or higher) late at night I tend to fall asleep more when compared to MP3 listening. Does that prove anything? No - of course not. But can you prove that my nervous system does not react positively to the 80% of content that has not been removed!

Just to save 5 seconds of download time?

So your answer is presumably that you wouldn't be able to tell? Your opinion appears to be that it's only a concern with MP3's, because you've been told it's not a lossless system.

Does this mean you never watch TV any more?.

If such an imaginary orange existed, I don't see as it would be any problem?.

I do exactly the same and for the same reasons!

I believe with some of the file downloading sites you don't actually "own" the files at all, the money you pay is, in effect, a right to use fee that expires when you do!

I take photographs in RAW image format, convert them to loss-less TIFF and then create JPEGs from the TIFF files, because I can manipulate the TIFF files as much as I like without worrying about loss of quality unlike a JPEG image.

A CD can be ripped to a lossless format such as FLAC for backup. FLAC then converted to lossy Variable bit rate MP3 (V2) to be copied to MP3 Players or memory sticks for playback on the go!

For some portable devices size is important, most the the apple devices do not have removable storage so carrying an iPOD touch on a trip there decisions to be made as to what to take!

Remember to that the quality of the headphones is important to. There's no point having the largest best quality files if your listening to then through cheap headphones!

All things being equal the CD will be slightly better but it will usually be hard to notice unless you do A/B switching on a high end Hi-Fi system.

But things are NOT equal. CD masters are often horribly compressed dynamically (so everything sounds loud, even if that wasn't the artist's intention) and in such cases, most cases, a 256 or 320Kbps mp3 is going to sound as good as the CD.

I was lucky enough to be sent a few 320Kbps mp3s of classical-pop type tracks (good singer, real orchestra) after the final mix but before the CD mastering. The mp3s are of noticeably better quality than the final CD version, which is horribly compressed dynamically, losing many of the delicate nuances of the artist(s) performance.

There are far greater effects on the final sound quality than the tiny differences between 320K mp3s and CDs. The main exceptions would be high quality performances and masters of classical music released by the likes of Deutsche Grammophon, and if you are lucky Decca or Sony Classical when played on a high quality hi-fi system. They do not use the obnoxious practices prevalent in the Cowell-esque CD making industry (including his so-called classical stars).

No - that's what you are saying.
I am saying that Music and the effect that Music has on human beings is a fairly complex matter. You seem to be saying that because you are unable to explain what is in the missing 80%, and what it's importance is, you will simply cast it aside.
The Orange with 80% missing - apparently undetectable - is of no importance to you.
What other areas of life are so trivial to you? What about romance. If a partner decides to reduce their love for you to a level that is detectable (the equivalent of 16 Kbps ) - and then raises it just above that level - it that OK in your world?

Is this an over reaction? After all it's only music we are discussing here.

It does depend a lot on what you listen to - plus the system. I'm mainly a classical bod and at low volumes I find that Radio 3 DAB (MP2 160 kb/s) is fine, Turn up the volume and I change to Radio 3 HD for preference (AAC MP4 320 kb/s).

It really does make a difference, especially on complex choral works - you can hear obvious glitches at the lower rate.

On my cinema system, which has a rather more costly sound setup, I sometimes play concerts from the Proms, the ones on BBC2 tend to be in 5.1 format and they can sometimes sound a bit bad actually.

One of the problems in having a good system is that poor sources sound much worse.

One classic example of the bad old days of 128kbps or 96kbps rips of AAC files - burned to CD or played out at a pub near me... someone was playing a Chic track treated like this..

WHERE THE BLOODY HELL WAS BERNARD'S BASSLINE?

It was rolled off below 90Hz which sounded AWFUL!

Is there a difference.... Well yes.

Is it noticeable? That depends a lot on the type of music, the compression and the algorithm used, on what the music is played and also a persons tolerance of progressively poorer quality recordings.

IMO though iTunes downloads have less to do with quality (or the lack thereof) and more to do with convenience, and cherry-picking tracks rather than playing albums, and folk forgetting that other methods such as home rips exist.

I also have some sacd discs, a format that I believe is effectively obsolete in the UK. They do sound better than cd but the range of artists available is somewhat limited and prices can be discouraging.