WAV vs FLAC revisited

[mauidan]

Ripped one of favorite CDs with dbPoweramp into uncompressed FLAC and
compared it to the same CD ripped to WAV using Audiograbber with it's rip to ram
setting.

On my set up the WAV version sounds more open with a deeper and
wider sounstage. Funny thing is dbPoweramp embedded artwork from totally different
CD.

 

[RBFC]

On my set up the WAV version sounds more open with a deeper and
wider sounstage.

This is what we heard at my place comparing several different recordings at 16/44.1 resolution.

Now, the question is why......

I have documented my experiences with CPU load and playback quality differences here:

http://www.whatsbestforum.com/showt...ing-a-Computer-Based-Music-Server-for-Dummies

The effect of CPU workload on sound quality is not in question for me any more. The remaining issue is: In an individual playback system, how can one know exactly where the CPU "safe limit" lies, and what techniques can be used to lower the load if playback quality is affected in this specific playback chain?



Lee

 

[fas42]

This is what we heard at my place comparing several different recordings at 16/44.1 resolution.

Now, the question is why......

The effect of CPU workload on sound quality is not in question for me any more. The remaining issue is: In an individual playback system, how can one know exactly where the CPU "safe limit" lies, and what techniques can be used to lower the load if playback quality is affected in this specific playback chain?



Lee

From my experience I would say this could be caused by three possible factors: 1) the different loads on the CPU alter the pattern of power supply current draw for the computer, which then impacts the power supplies of other equipment; 2) the computer is generating RF interference all the time while it operates, and again the pattern of interference alters with different CPU loads; and 3) high frequency interference is being injected into the USB data stream.

I have my doubts about 1) because of the nature of computer gear power supplies, but it would be worth experimenting with putting isolation units on the mains input to the server.

With 2), try moving the server different distances from the audio gear without changing anything else, from a couple of feet away to as far as possible, see if that makes a difference. Even do something silly like enclosing the whole server in Al foil and earthing that, temporarily ...

3) is the most likely, and this would involve trying all the the buffering devices out there, what Amir and others have had good experience with. I would even try cascading buffers, that may improve the isolation.

Frank

 

[mauidan]

This is what we heard at my place comparing several different recordings at 16/44.1 resolution.

Now, the question is why......

I have documented my experiences with CPU load and playback quality differences here:

http://www.whatsbestforum.com/showt...ing-a-Computer-Based-Music-Server-for-Dummies

The effect of CPU workload on sound quality is not in question for me any more. The remaining issue is: In an individual playback system, how can one know exactly where the CPU "safe limit" lies, and what techniques can be used to lower the load if playback quality is affected in this specific playback chain?
Lee

Nice to know that I'm in good company.

I can't comment on CPU Load since there isn't any PC/MAC in my digital playback set up.

 

[Phelonious Ponk]

From my experience I would say this could be caused by three possible factors: 1) the different loads on the CPU alter the pattern of power supply current draw for the computer, which then impacts the power supplies of other equipment; 2) the computer is generating RF interference all the time while it operates, and again the pattern of interference alters with different CPU loads; and 3) high frequency interference is being injected into the USB data stream.

I have my doubts about 1) because of the nature of computer gear power supplies, but it would be worth experimenting with putting isolation units on the mains input to the server.

With 2), try moving the server different distances from the audio gear without changing anything else, from a couple of feet away to as far as possible, see if that makes a difference. Even do something silly like enclosing the whole server in Al foil and earthing that, temporarily ...

3) is the most likely, and this would involve trying all the the buffering devices out there, what Amir and others have had good experience with. I would even try cascading buffers, that may improve the isolation.

Frank

4) Expectation bias. And that's the one that is most likely. We are all quietly impacted by expectation bias in our lives all the time. Audio is not only not an exception, it is incredibly fertile ground. And almost every time something like this is re-tested in blind listening, the "differences" become indistinguishable. False perception is the most likely cause IMO, and I feel compelled to finish by saying I mean no offense to anyone, because audiophiles often seem to be very offended by the suggestion. I don't understand that. Knowing what we know about the frailty of auditory memory and the power of expectation, we should all be double-checking our perceptions regularly instead of loudly defending ourselves against anything that questions them. In the meantime, rip WAV files and enjoy the music.

Tim

 

[Phelonious Ponk]

Nice to know that I'm in good company.

I can't comment on CPU Load since there isn't any PC/MAC in my digital playback set up.

I'm confused. After you rip the file are you copying it to some medium for playback? if there is no PC/Mac in your digital playback set up, what's playing the file?

Tim

 

[RBFC]

I'm confused. After you rip the file are you copying it to some medium for playback? if there is no PC/Mac in your digital playback set up, what's playing the file?

Tim

I was wondering the same. Perhaps he's burning the files to disc before playing?

Lee

 

[mauidan]

I was wondering the same. Perhaps he's burning the files to disc before playing?

Lee

The ripped files are on a network HD. The DAC is connected to the network via CAT 5e. An app on my Ipad sees the HD and DAC on the netwok and selects the files to be played.

 

[Phelonious Ponk]

The ripped files are on a network HD. The DAC is connected to the network via CAT 5e. An app on my Ipad sees the HD and DAC on the netwok and selects the files to be played.

I assume the app on the iPad plays the file as well? Something has to.

Tim

 

[rbbert]

there's a computer in there somewhere. If it's an NAS drive, there is a little computer in the NAS drive itself.

 

[Phelonious Ponk]

there's a computer in there somewhere.

Yep. Thus the question what's playing the files. Find out where the software resides and you've found the computer. Probably the iPad. Not a bad place for it to be. Dead quiet, no electronic connection to the DAC...Of course there's a wire between the network drive and the DAC, and an unshielded one at that. But if it sounds good, I wouldn't spend a moment worrying about it.

Tim

 

[mauidan]

there's a computer in there somewhere. If it's an NAS drive, there is a little computer in the NAS drive itself.

No NAS. The HD is connected to a router with a ReadySHARE USB port.

The Ipad app tells the DAC (PWD/Bridge) which files to play, and the app and the Ipad are turned off.

 

[rbbert]

So the computer's in the PS Audio DAC; should be good!

 

[Vincent Kars]

So the computer's in the PS Audio DAC; should be good!

No, this is a DLNA setup.
the NAS functions as a DLNA server.
The Bridge as a renderer
The app on the iPad is the Controller.

http://thewelltemperedcomputer.com/KB/DLNA.htm

 

[fas42]

As has been said, if the file sits on a hard disk, and you hear music playing then a computer is operating somewhere: it may be hidden, it may be small, but it is there. And therefore can generate interference. Tim's expectation bias may figure for some people, but not for me. As an example, my HT has gone off the boil at the moment, perhaps its age is catching up with it, or I've accidentially disturbed or undone a tweak, but it's not firing. All my beliefs about how good it should sound doesn't change the fact that it's sounding, to me, pretty crappy at the moment. So expectation will only get you so far ..

Frank

 

[rbbert]

No, this is a DLNA setup.
the NAS functions as a DLNA server.
The Bridge as a renderer
The app on the iPad is the Controller.

http://thewelltemperedcomputer.com/KB/DLNA.htm

Isn't this what I posted??

 

[Phelonious Ponk]

As has been said, if the file sits on a hard disk, and you hear music playing then a computer is operating somewhere: it may be hidden, it may be small, but it is there. And therefore can generate interference. Tim's expectation bias may figure for some people, but not for me. As an example, my HT has gone off the boil at the moment, perhaps its age is catching up with it, or I've accidentially disturbed or undone a tweak, but it's not firing. All my beliefs about how good it should sound doesn't change the fact that it's sounding, to me, pretty crappy at the moment. So expectation will only get you so far ..

Frank

Frank, Frank, Frank... Never, in all of my days, have I seen expectations get anyone so far! You, sir, sell your expectations far short. Your expectations have brought you more from a HTIB than well-heeled audiophiles get from their six figure systems. A bit of solder and your expectations can take off in a rocket's blast and not only defy gravity, but reality! Sometimes, when deep in one of your conversations about "perceptions" you nearly get to understanding and embracing the awesome power of your own expectations, but you always stop short of waking from the dream.

When I say "expectation bias," though, I'm not referring to you. Expectation bias is as common as air. The realization of your expectations? This is the stuff of legends!

Tim

 

[fas42]

Ahhh, I feel better now: a good dose of Timism, or should that be Ponkism, goes a long, loooong way, shakes off the morning blues!! :b

Well, I did find a problem with the HT, see if that sorts it out for the day. Micro gave me the clue of how to describe what I'm dealing with, with the setup: when it works well it projects the soundverse of the MBL "melons" with a good recording, but when it falters it sounds like the same speakers on a bad day, with a bad recording. So it's chalk and cheese; either on song, or bad enough to send most of you here out of the room, if you were here! That's the big downside with what I'm playing with, the level of tolerance of the system to any problems is very low ...

To get back on topic, that's the general problem to some degree with digital as well: it either works extremely well, or is terribly flat, irritating, and unpleasant. Using a server should make the job easier, but imperfections in the setup can still be very audible; hence the discussion on CPU load. Another way of looking at it is that there are 2 strategies: create the right workload on the CPU to give best sound; or, isolate the audio stages so that CPU activity has zero effect on the sound. The latter way, for me, would be the best technique because it will typically also prevent interference from other areas as well ...

Frank

 

[Mitchco]

Maybe my approach was not too scientific, but...

http://www.computeraudiophile.com/blogs/FLAC-vs-WAV-vs-MP3-vs-M4A-Experiment

This was the computer used, nothing special:
http://i1217.photobucket.com/albums/dd381/mitchatola/Win7PC.jpg

 

[fas42]

Maybe my approach was not too scientific, but...

http://www.computeraudiophile.com/blogs/FLAC-vs-WAV-vs-MP3-vs-M4A-Experiment

This was the computer used, nothing special:
http://i1217.photobucket.com/albums/dd381/mitchatola/Win7PC.jpg

Excellent article, Mitchco, covered all the bases very nicely, thanks for putting the link here ...

Frank