Am I correct that decompressing to WAV cannot reverse loss of quality?, [TOS #6: was "mp3 to wav quality" in General Audio] Options

[Paul77]

Hi

I have just used winamp to convert some mp3 files to wav for recording to cd (as the tracks are only available on Amazon as mp3 currently).

Wav's are 7 or 8 times the size of mp3's due to the compression. When you decompress to wav can you only ever get the quality that was present in the mp3. That is when the mp3 was created from the original source some loss of quality is inevitable and decompressing to wav presumably cannot reverse that loss of quality so my wav files presumably cannot sound as good as on a purchased CD.

Can someone confirm this is about right or have I missed something?

[greynol]

If such software doesn't honor gapless decoding, or if it does but the tracks weren't properly cut to CDDA frame boundaries then I wouldn't rely on it when dealing with gapless material.

[Paul77]

I was using XP CD burner software so I don't think it will convert from mp3 to wav.
Out of interest I'll try converting an mp3 to wav for a track I have on a purchased CD
to see if can tell the difference (mp3 encoding is supposed to cut out frequencies that
are not audible and be efficient in compressing the rest)!





This post has been edited by Paul77: Apr 18 2012, 16:59

[dhromed]

I was using XP CD burner software so I don't think it will convert from mp3 to wav.

CDBurnerXP will be just fine.

[Paul77]

I was using XP CD burner software so I don't think it will convert from mp3 to wav.

CDBurnerXP will be just fine.

Have tried dragging and dropping mp3 file onto cd drive and then clicking on write - it does work in that a track is recorded to disk and it plays on my cd player - so presumably its a wav file but Windows Media Player changed the title to 'Track01.cda' on the disk. I guess this can be changed in the media player.

"That doesn't sound like it would be a proper apples to apples double-blind comparison. To compare mp3 to lossless, you need to create the mp3 from the lossless source and use something like the ABX comparator in fobar2000 in order to prevent expectation bias."

I imagine the mp3 file from Amazon is created from a lossless source.

Have compared an Amazon mp3 track I've on a purchased CD and its quite easy to hear the difference - just in the depth/detail of the bass and detail of the background instruments at the start of the track.

Wonder what SACD would have been like?

[db1989]

Notwithstanding that being pretty obvious, the point is not about the source of Amazon’s MP3s. The point is that you didn’t compare the files in a valid way. What you have just said is in clear violation of the terms of service to which you agreed upon registering here. Perform a proper comparison and give us proper results, or stop using vague buzzwords such as “depth” and “detail” to describe what is quite probably merely a result of your expectation bias and the placebo effect.

[greynol]

To add to dB1989's post, the mp3 must be compared to the actual lossless source that was used to create it. Just having the CD does not mean that the digital audio on it is the same as that used to create the mp3 that came from Amazon. It could have originated from a completely different master or be shifted in time by a noticeable amount even if it was from the same master.

To compare mp3 to lossless, you need to create the mp3 from the lossless source [...]

My use of the word "the" in "the lossless source" wasn't accidental.

Once the criteria of comparing the lossless source against its lossy counterpart is met, if the test is still not double-blind then the results are completely useless and their presentation is not welcome here.

This post has been edited by greynol: Apr 19 2012, 18:47