no quality loss with wav?

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jperkins
Posts: 3
Joined: Sun May 28, 2006 7:48 pm

no quality loss with wav?

Post by jperkins »

I'm new to Goldwave. Looks great!

I'm trying to do very simple tasks. Either merging or splitting .wav files. Technique is simple, but I am curious - am I losing any sound quality in the process, or am I getting "bit-perfect" output files.

Input files are all 44.1k, 16 bit stereo, ripped from CD by Exact Audio Copy.

Files are opened in GW (5.13), 2nd file copy pasted to the end of the 1st open file, and then saved as new file in 44.1k, 16 bit stereo .wav.

When I play the original and new .wav files back through a quality stereo, I would expect identical passages to sound "identical" (bit-perfect copies).

However, I perceive that the original file sounds slightly better (clearer), especially in treble. When doing (loosely controlled) blind A/B listening between the files, both my wife (talented ears) and I seem to be able to pick the orginal file correctly a significant percentage of the time - and express a preference for it.

Are we imagining the difference? Should the copy be "bit-perfect and identical", or would GW potentially be altering the sound quailty with this simple copy and save process of .wav files?

Are there special techniques I should be following to assure bit-perfect output files?

Thanks!
Blandine Catastrophe
Posts: 253
Joined: Sun Jul 24, 2005 3:25 pm

Post by Blandine Catastrophe »

There are no losses in such a process as long as you needn't to do anything else that things like copy/cut/paste/edit/merge/split... and as long as you don't resample from a rate to antoher one.

The only problem you could face is a small clic if there is a huge offset center difference between two merged tracks, but something huge enough to provoque that is rather improbable.
Gloup? :-°
jperkins
Posts: 3
Joined: Sun May 28, 2006 7:48 pm

Post by jperkins »

Thanks! That's good to hear.

Followup question - if I do very simple edits (fade-in or fade-out) on the last 3 seconds of a file), will GW resample the whole file, and potentially introduce sound degradation? Or is the unedited portion of the file saved bit-perfect, with just the fades being affected? (again, opening and saving 44.1k, 16 bit stereo .wav files).

Cheers!
Togglehead
Posts: 98
Joined: Mon Apr 10, 2006 1:37 pm
Location: Jersey

Post by Togglehead »

also when doin volume adjusments...it only adjust what YOU tell it to.

The only time it will resample or convert a song is when you tell it to.

...it'll even tell you whether or not the file can be saved in the desired sample rate....as a bit of error prevention.

Side: this doesnt happen to be jperkins From NJ does it?
DougDbug
Posts: 2172
Joined: Wed Feb 16, 2005 3:33 pm
Location: Silicon Valley

Post by DougDbug »

However, I perceive that the original file sounds slightly better (clearer), especially in treble. When doing (loosely controlled) blind A/B listening between the files, both my wife (talented ears) and I seem to be able to pick the orginal file correctly a significant percentage of the time - and express a preference for it.
If you are comparing the CD playback to the WAV file playback... There is a difference in the way your computer plays a CD, and how it plays a WAV file. The CD player in your computer has a built-in digital-to-analog converter. Analog audio is sent to your soundcard (or soundchip). When you play a WAV file, the digital data is sent over the data bus and the soundcard's (or soundchip's) digital-to-analog converter is used to play the sound. (Some computers have a direct-digital connection between the CD player and the soundcard... But the "path" is still different from the WAV path, and the digital-to-analog conversion may be different.)

But, none of this affects the actual digital data. The WAV file and the CD both contain the same PCM data in a different "package". So, you can convert back and forth between then all day long without any loss... sort of like converting between "10" and "ten".
jperkins
Posts: 3
Joined: Sun May 28, 2006 7:48 pm

Post by jperkins »

Thanks all.

Listening tests have all been .wav files from the computer, ethernet digital output thru a SlimDevices Squeezebox (great device!) thru spdif optical digital output to an external Bel Canto DAC2 (luv it's quality, too), and on to the audio amp. So ther should be no variability in the equipment chain.

I believe the discussion that the non-resampled .wav output file from GW is bit perfect copy of the input .wav file. Just to clear my mind, I'll do some more controlled A/B listening this weekend to see if I can figure out what I might have been hearing (or imagining) as a difference.

All sounds good so far.

btw - not the jperkins from NJ - other coast.

Cheers!
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