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FLAC vs. WAV Format - Surprising Quality Differences  

post #1 of 210
Thread Starter 
I have noticed quite a difference in quality between FLAC and Wav files with regard to playback quality.

The story begins where I downloaded an album by Thomas Feiner and Anywhen in FLAC format (Samadhisound.com)

Also I recently upgraded my system a bit - PC > Yulong DAH1 Mark > Senn HD650 & STAX SRS-3050

However this stunning album seemed quite harsh especially Thomas' vocals, and the sound stage appeared fairly flat - two dimensional. Separation between instruments also sounded a little smeared.

I tried this recording with the STAX and the Senns, same problems.

However, I decided to convert the FLAC files to WAV (using DBPOWERAMP)
and discovered something unexpected - but a pleasant surprise indeed.

All of the problems I had experienced are now gone. It appears that the FLAC file despite being lossless, has some effects on playback.

I tend to upsample (SRC in Foobar) to 88.2khz / 24bit and this is where the effects were most marked.

Anyway just a point to discuss - am I the only one who has this experience?
post #2 of 210
There must be something wrong with the software you are using...

This shouldn't be.
post #3 of 210
Is it just level differences if replaygain was applied to the flac?

Otherwise, it doesn't make any sense!
post #4 of 210
Oh, and use the ABX plugin and foobar then post your accuracy
post #5 of 210
Does not make sense to me either.
But that said, you're not the only one claiming to hear a difference between uncompressed PCM (WAV) and lossless compressed PCM (FLAC).

post #6 of 210
If I recall correctly, FLAC doesn't always mean it will sound identical to the original source, since it still has compression. The higher FLAC compression level used for FLAC will determine its SQ. Lossless really means that the FLAC file contains all the data necessary to decompress into a WAV file that's identical to the original source, not the actual SQ. Correct me if I'm wrong, by the way.
post #7 of 210
robojack: The flac should be compressed on the fly by the software playing it back to output the same sound as the WAV file. Same SQ = lossless. What must be going on is that the software doing the playback has issues.
post #8 of 210
Quote:
Originally Posted by krmathis View Post
Does not make sense to me either.
But that said, you're not the only one claiming to hear a difference between uncompressed PCM (WAV) and lossless compressed PCM (FLAC).

That's because something isn't working properly in the chain. Either some plugins, or codecs, idk... something isn't adequate.
post #9 of 210
Quote:
Originally Posted by Abubizarre View Post
am I the only one who has this experience?
yes, and your post makes no sense either. if you created the WAV from the FLAC, then both of those waveforms are bit-identical. you can see it by loading both the flac and wav file into an audio editor and overlay them. they will be exactly the same.

the only possible reason for the files sounding different is some serious error in the decoders you are using to play them back.
post #10 of 210
Quote:
Originally Posted by robojack View Post
If I recall correctly, FLAC doesn't always mean it will sound identical to the original source, since it still has compression. The higher FLAC compression level used for FLAC will determine its SQ. Lossless really means that the FLAC file contains all the data necessary to decompress into a WAV file that's identical to the original source, not the actual SQ. Correct me if I'm wrong, by the way.
yes, you are completely wrong. the only difference between the various "compression levels" is resulting filesize and encoding speed, i.e. higher levels mean smaller files but the encoding takes more time. the sound itself is ALWAYS bit-identical to the source.
post #11 of 210
Perhaps back 10 years ago, decompressing a FLAC file may have resulted in sound differences because the system couldn't cache the entire track in RAM. These days one can cue up an album and the entire thing can be decompressed and stored in RAM as WAV files ready to go. 1 CPU does the decompression, 1 CPU does the playback. Seriously, with the computers today, there should be no sonic differences at all.
post #12 of 210
I wouldn't wonder if there are differences in decoding modules, ie. those programs that convert the file to audio stream. Years ago, there was much discussion how winamp's default MP3 decoder was bad in SQ and the MADlib decoder was the best alternative.
post #13 of 210
Well, dbpoweramp uses the same flac library as EAC and I believe most use the same library (perhaps different versions...but from same organization) so I don't think this would be so. md5 checksum is the way to go here
post #14 of 210
Quote:
Originally Posted by Zanth View Post
Perhaps back 10 years ago, decompressing a FLAC file may have resulted in sound differences because the system couldn't cache the entire track in RAM. These days one can cue up an album and the entire thing can be decompressed and stored in RAM as WAV files ready to go. 1 CPU does the decompression, 1 CPU does the playback. Seriously, with the computers today, there should be no sonic differences at all.
Well of course it's all about bad software, lack of buffers, and underperforming computers, since (as everyone else has said) the decompressed FLAC is bit-for-bit identical to the uncompressed WAV.

But we have hard real-time processing requirements when playing music, and I don't think these problems have vanished as much as people here believe.

Running upsampling in foobar on an underpowered PC with 20 other programs and virus checking / email polling in the background and who knows if the FLAC gets decompressed correctly. You will get a well-formed bitstream from foobar no matter what, so unless you have rigged something special you will never know if there are decompression errors.
post #15 of 210
You did not just make this topic.
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