[Strangelove424]

Spoiler

I wonder which Admin is the one who occasionally thinks it might be a good idea to move stuff like this into our forum? Does he think it's like throwing meat to the lions or something?

 

[bigshot]

A null test is where two signals or files are summed with one inverted so the result is only the difference between them. Essentially one is subtracted from the other. It's an indicator of how similar or different the two are. Identical data produces a perfect null reading the equivalent of no audio.

The files tested were all 16/44.1, so the theoretical noise floor of a file would be 96dB. Since the resulting nulls were over 100dB, that indicates all files contained identical data, there was no difference. The summing engine uses 64 bit floating point math, hence the greater than theoretical noise floor null.

DJtheAudiophile, that means that there should be no audible difference between ALAC and WAV because they are identical within the range of human hearing. If you are hearing a difference it would have to be because either 1) your playback system is unable to properly unpack the ALAC (very unlikely because I'm sure your equipment is good enough to do that correctly) or 2) your comparison was done in a way that perceptual bias came into it (one track being louder than the other, too much time between comparison samples, bias due to file size- it's a bigger file, it HAS to sound better)

Thanks Pinnahertz for helping us clear this up. I hope this was interesting and will help you in the future, DJtheAudiophile.

 

[castleofargh]

Sound quality. The alac sounded muffled and empty compared to the Uncompressed Wav File.

as the other said, from a technical point of view, 2 lossless formats have no reason to make any difference. it's like archiving a file into .zip or .rar, once extracted and used, the files are the same.
that doesn't mean there absolutely cannot be an audible difference, but at the very least it does tell us that the cause for the difference is not the format itself. which leads to wondering if the user dreams the difference, created the difference by messing up the conversion settings, or if maybe the playback software/device is just so very very weak and buggy that the extraction process ends up impacting the sound somehow(absolutely not normal and I would blame the device 100% of the time instead of alac, or flac).