[Tirade]

This should be a good topic to get the discless forum going

http://www.stereophile.com/features/308mp3cd/

[BradJudy]

There's no way this chart comes from a 128kbps mp3 - there's a low-pass filter on mp3 and at 128kbps there should be a steep drop off starting at 16kHz IIRC.  It should look like his AAC chart.  The lowpass filter is built into the mp3 encoding and should be in any file to varying degrees (I think 320kbps still has an 18kHz filter)

[Charles Calkins]

Beats the living crap out of me what all this mumbo jumbo means. When I download music to itunes from a CD it's set for apple lossless. When I buy an mp3 tune from Amazon it gets to itunes as an mp3 download. They all sound pretty good to me. If there is a difference I can't hear it. Am I missing something?

                                                Cheers
                                                 Charlie

[darrenyeats]

For me, a distraction from a more important debate: CD vs hi-rez formats. Personally I believe CD is already transparent, and hi-rez formats are a waste of (a) time (b) money and (c) freedom which we enjoy currently with CD-based music (hi-rez formats are all about the DRM folks...)

As for lossy vs CD, they might be indistinguishable and they might not. The time is coming soon when lossless will reign complete, for the simple reason there will be zero (zilch, nada) point saving space on lossy. We're already there on computers and we'll be there soon on music players. If CD was burdened by DRM it would be a question worth agonising over...but in fact lossy downloads often have DRM!...and CD is fully flexible.
Darren

[BradJudy]

I remembered that I had some some spectral plots of this back in 2005 that illustrate my point:

http://www.bradjudy.com/audioblog/2005/09/11/affects-of-data-compression-on-frequency-content/

If you click on the WAV, 256 kbps mp3 and 128kbps mp3, they should open in different tabs and you can easily see the low-pass filter I mentioned that doesn't appear in the article.  Because "Sweet Child o Mine" is a wall of sound, it does a good job showing this point. 

I did the same shots with FLAC and OGG as well:

http://www.bradjudy.com/audioblog/2005/09/12/more-compression-spectrum-analysis/