Flac -> Wav conversion

Posted by: Graham Russell on 27 September 2008

Hi,

I've been comparing Flac vs Wav versions of a few tracks (via Sonos ZP90 & Chord Signature phono cable) into 552/500. Wav sounds better and closes the gap on CD555. I have just finished converting all my CDs (approx 800) into Flac. If I convert Flac files into Wav will they sound the same as if the original tracks were ripped as Wav?

I'm considering batch converting everything from Flac to Wav if the resulting files are the same as directly ripped Wavs.

Assuming Flac really is lossless then it will be possible to recreate the Wav files.

I'd appreciate feedback from those who have experience with this.

Cheers
Graham
Posted on: 29 September 2008 by David Dever
The HDX does not tag WAV files, but stores the info in a local database as well as an XML file.

As for sound quality comparisons between FLAC decoded in real-time and WAV–there are differing levels of compression at the FLAC encoding stage which affect processing resources on the decoding stage. This can affect sound quality–best to test with varying degrees of compression to validate this perceived effect.

There is no reason to suspect that a FLAC file which has been decoded to WAV offline should sound any different than a WAV file containing the same PCM data.
Posted on: 29 September 2008 by Mark R
quote:
The HDX does not tag WAV files, but stores the info in a local database as well as an XML file.


Interesting clarification. I'd be interested to see how the tagging is done when the rips are enabled for external disks - is it proprietary to the extent that other apps would not be able to read the tagging (not sure of 'standardisation' of WAV tagging)?

I recall from a prior thread, quite a while ago, that the NS01 would rip MP3 versions at the same time as the WAV rip. Is this still the case and is it the case for the HDX as well? Is ID3 used for this MP3 tagging?
Posted on: 29 September 2008 by Graham Russell
quote:
Originally posted by David Dever:
As for sound quality comparisons between FLAC decoded in real-time and WAV–there are differing levels of compression at the FLAC encoding stage which affect processing resources on the decoding stage. This can affect sound quality–best to test with varying degrees of compression to validate this perceived effect.

There is no reason to suspect that a FLAC file which has been decoded to WAV offline should sound any different than a WAV file containing the same PCM data.


Very interesting comment about Flac compression level affecting the quality of playback. I ripped all my CDs with level 6 Flac compression. Having converted them back to WAV, the WAV files are clearly better sounding. Perhaps I should have used less Flac compression? Time for more experimentation..... Smile
Posted on: 29 September 2008 by Graham Russell
Hmmm, interesting...

Just converted a few Flacs from level 6 to level 0 (least compression). The level 0 Flacs sound better and close the gap on Wavs. I think Wav still sounds better though. My ears are getting tired so I'll try comparing them again tomorrow.

The file size between Flac level 6 and level 0 is not too much. I think I'll batch convert all my Flacs to level 0. The great thing about these lossless formats is that I won't lose any information.
Posted on: 29 September 2008 by js
With storage so cheap, why not just store them as wave if you can even hear a slight difference in playback? You're probably only saving about 1/3 the space at that setting.
Posted on: 29 September 2008 by Graham Russell
That's the final plan. Right now I have approx 700 CDs stored as both Flac and Wav. However, I'm not too keen to lose the meta data in the Flac files. I've had to edit some of them to correct meta data import errors during original ripping.

It has been an interesting period of experimentation to compare and contrast different formats and compressions.
Posted on: 29 September 2008 by js
Smile
Posted on: 30 September 2008 by pcstockton
There are some individuals with VERY acute hearing on this forum it seems.

If you can hear a difference between the levels of FLAC you have ears better than I do.... as well as my dog... and my pet bat.
Posted on: 30 September 2008 by David Dever
Makes sense, though, as every DSP algorithm has a mechanical or analogue, err, analog.
Posted on: 30 September 2008 by Paul Hutchings
So what level of usage is the CPU in the HDX (or any other similar device) running at when decoding for the additional overhead of decoding a more highly compressed FLAC file to make a difference in the sound quality?
Posted on: 30 September 2008 by Steve S1
quote:
Originally posted by pcstockton:
There are some individuals with VERY acute hearing on this forum it seems.

If you can hear a difference between the levels of FLAC you have ears better than I do.... as well as my dog... and my pet bat.


Be fun to see them blind test it - amazing what expectation taken out of things does. I'm afraid hearing differences between lossless formats (all other things equal) is just salesman's pixie dust.

Try the blind tests, Seen it done on a couple of systems now - nobody was able to pick FLAC/WAV/Apple Lossless at better than the usual guess ratio.

If it amuses people....no harm, of course.

Steve
Posted on: 30 September 2008 by Graham Russell
quote:
Originally posted by Steve S1:
quote:
Originally posted by pcstockton:
There are some individuals with VERY acute hearing on this forum it seems.

If you can hear a difference between the levels of FLAC you have ears better than I do.... as well as my dog... and my pet bat.


Be fun to see them blind test it - amazing what expectation taken out of things does. I'm afraid hearing differences between lossless formats (all other things equal) is just salesman's pixie dust.

Try the blind tests, Seen it done on a couple of systems now - nobody was able to pick FLAC/WAV/Apple Lossless at better than the usual guess ratio.

If it amuses people....no harm, of course.

Steve


Sorry, but I totally disagree. There is a difference on the set up I've been using. Perhaps the Sonos decoding box is the issue.

James N is coming over tonight with his Mac/Lavry system for some fun and games. I'm interested to see if his system plays Flac and Wav the same through my 552/500.
Posted on: 30 September 2008 by Steve S1
quote:
Originally posted by Graham Russell:

Sorry, but I totally disagree. There is a difference on the set up I've been using. Perhaps the Sonos decoding box is the issue.

James N is coming over tonight with his Mac/Lavry system for some fun and games. I'm interested to see if his system plays Flac and Wav the same through my 552/500.


Have fun Graham, not familiar with Sonos - done plenty of PC and Mac stuff with FLAC/WAV/AL - gave up worrying about that, the rips sounded great, all of them.

Never mind all the rip mumbo jumbo, I hope you come away with some new tunes. Big Grin
Posted on: 30 September 2008 by glevethan
quote:
Originally posted by Graham Russell:

James N is coming over tonight with his Mac/Lavry system for some fun and games. I'm interested to see if his system plays Flac and Wav the same through my 552/500.


Please report back to us on your Mac/Lavry impressions.

Thanks
Gregg
Posted on: 30 September 2008 by js
quote:
Originally posted by Steve S1:
quote:
Originally posted by pcstockton:
There are some individuals with VERY acute hearing on this forum it seems.

If you can hear a difference between the levels of FLAC you have ears better than I do.... as well as my dog... and my pet bat.


Be fun to see them blind test it - amazing what expectation taken out of things does. I'm afraid hearing differences between lossless formats (all other things equal) is just salesman's pixie dust.

Try the blind tests, Seen it done on a couple of systems now - nobody was able to pick FLAC/WAV/Apple Lossless at better than the usual guess ratio.

If it amuses people....no harm, of course.

Steve
I suspect Graham expected it to sound the same or he wouldn't have saved so much material to FLAC. A post here probably got him to listen for himself. I was also surprised to hear difference not only in lossless but various types with my laptop. They're probably all fine if converted back to Wave.
Posted on: 30 September 2008 by pcstockton
It is funny to be on the other side of the tracks for once.

Many eschew my ripping process in defense of an Itunes/burst mode method. Saying they cannot hear the difference, so why bother.

I, for one, have tried MANY lossless codecs as well as WAV, and have never been able to tell the difference. From APE, Wavepack, ALAC, FLAC, WAV, OGG FLAC, etc...

You would have to have an extremely underpowered CPU for ANY of these to demand much from your system upon playback.

And FLAC is by far the least intensive compression codec on the replay (decoding) side of things. With FLAC, all the time and CPU usage happens during encoding.

Strange.... But oh well.

It seems WAVs and Burst mode are popular among the Mac users. While FLAC and Secure Mode/EAC style ripping seem more prevalent for PCs.

The irony is that a proper EAC rip to WAV is probably the best way to go, not considering playback.
Posted on: 30 September 2008 by Graham Russell
Please bear in mind all my listening tests have been carried out with a Sonos ZP90 as the source. It may not have sufficient processing power to decompress Flac files as well as it can handle Wav files.

I haven't tried comparing Flac and Wav via a laptop through my system.
Posted on: 30 September 2008 by pcstockton
Graham,

That very well could be. I wouldn't be surprised.

I saw a Sonos at Best Buy the other day.... for what that is worth.

Can you use the Sonos directly with a computer as the source? Is there a digital input on the "DAC" portion?
Posted on: 30 September 2008 by js
quote:
Originally posted by pcstockton:
Graham,

That very well could be. I wouldn't be surprised.

I saw a Sonos at Best Buy the other day.... for what that is worth.

Can you use the Sonos directly with a computer as the source? Is there a digital input on the "DAC" portion?
No dig in but a dig out. Has an A2D for analog in and a dig out that is always 16/44 regardless of source. No 24/96. Ethernet connected with a great interface and uses it's own internal player with access to any music files on your computer, Rhapsody, INT Radio etc. Does AAC, WMA, FLAC, WAVE besides others. Does a very nice job on the more compressed formats so FLAC should be easy. I don't think music is that stressful in general. Best Buy is required to sell them at the same price as I do. Pretty competent and musical for what it is.

My laptop is a Lenovo/XP pro, 3g ram, 8300 core duo and I keep my processes in check and no thinkvantage console. I swear it has tenticles. Smile I heard differences in all the lossless formats though most weren't better than others. APE seemed the best in real time. Used Media Jukebox with everything off, small output buffer and ASIO for playback through a TC & SN at the time. My guess is that they're all fine if brought back to wave first. I should do this again as I was just curious at the time and immediately threw away the files. I don't even recall if it was a 24 or 16 bit file to start.
Posted on: 01 October 2008 by james n
We had a play with Wav vrs Flac and through the Sonos there was a definite difference. To me the sound was more veiled with the flac file - playing the same track in wav format was much cleaner. Suprising i know and it must be just down to the extra processing occuring during the conversion. This was with the Sonos player piped into the Lavry.

Cheers

James

PS: The Sonos proved to be a very good source.
Posted on: 01 October 2008 by Steve S1
quote:
Originally posted by james n:
We had a play with Wav vrs Flac and through the Sonos there was a definite difference. To me the sound was more veiled with the flac file - playing the same track in wav format was much cleaner. Suprising i know and it must be just down to the extra processing occuring during the conversion. This was with the Sonos player piped into the Lavry.

Cheers

James

PS: The Sonos proved to be a very good source.


Hi James,

Were you able to try FLAC and WAV on anything else?

Steve
Posted on: 01 October 2008 by james n
Hi Steve,

IIRC we tried it on the Netgear streamer that Graham has but this didnt sound as good as the Sonos unit so we gave up on that one. We'd have tried Apple Lossless vrs AIFF if we'd have had time.

Cheers

James
Posted on: 01 October 2008 by Graham Russell
Once of the conclusions we came to was the Sonons via coax output sounded better than Mac via optical output. However, when we swapped coax for optical output from the Sonos the sound deteriorated a bit to probably Mac level.

I've always been led to believe that coax is better than optical for digital signals and this seems to reinforce that.

I think both Sonos and Mac are great players via the Lavry and because of the coax output the Sonos just edges it in musicality.

Neither are up to the quality of the CD555 - luckily for me Smile On some music the gap was pretty small and on others such as Shelby Lynne (which is mainly acoustic and very emotional) the gap big.

If I were starting from scratch wanting a good quality source with the convenience of streaming & jukebox benefits the Sonos/Lavry combination would be great. And at approx £1k for the pair it's great VFM. The multi-room capability of the Sonos is great if you're looking for a "lifestyle" system.

A big issue for me is the Sonons won't play 24/96. We tried it and the box got very unhappy. For high res audio playback the Mac is the ideal solution. I assume Sonos are working on a successor product that works with the high res audio formats. That will be a very interesting box to try Smile
Posted on: 01 October 2008 by Steve S1
quote:
Originally posted by Graham Russell:

I think both Sonos and Mac are great players via the Lavry and because of the coax output the Sonos just edges it in musicality.

Neither are up to the quality of the CD555 - luckily for me Smile On some music the gap was pretty small and on others such as Shelby Lynne (which is mainly acoustic and very emotional) the gap big.



Very interesting Graham. I certainly found the differences very small on most music at Tony's place. The occasional difference being a bit more "weight" to the sound with the 555. Very recording specific though.

Mind you, Tony has only one 555PS Big Grin How much closer do you think it would have been with just the one?

At least you can see (hear) why that little box has caused such a stir among 555 and CDS3 owners. Perhaps it likes 240v. Big Grin

Have you heard the HDX? If so, how would you say that might compare?

Glad you enjoyed yourselves.

Steve
Posted on: 01 October 2008 by Graham Russell
quote:
Originally posted by Steve S1:

Very interesting Graham. I certainly found the differences very small on most music at Tony's place. The occasional difference being a bit more "weight" to the sound with the 555. Very recording specific though.

Mind you, Tony has only one 555PS Big Grin How much closer do you think it would have been with just the one?

At least you can see (hear) why that little box has caused such a stir among 555 and CDS3 owners. Perhaps it likes 240v. Big Grin

Have you heard the HDX? If so, how would you say that might compare?

Glad you enjoyed yourselves.

Steve


I heard an HDX very quickly at home on Monday. Alan from PJ HiFi (who was dropping off some new Audiovector speakers and an Atlas Mavros phono cable for me to play with for a few days) just happened to have one in the car. We gave it a very quick spin and ripped one of my Kasey Chambers CDs for comparison. It sounded pretty flat. To be fair we didn't give a really serious listen. Alan said it ideally needs a 555PS to bring it to life.

I think with only a single PSU the 555 would still be much better than the Lavry. However in the config I have it the cd player costs approx £20k. An impossible question to answer is "is it £19k better than the Sonos/Lavry combination?" Big Grin

I wonder whether a better XLR->din cable would bring more improvements to the Lavry. On the back of the CD555 different cables make a big difference to the sound & musicality. (That's another can of worms I probably won't open though Smile ).