[justcurious]

ok, i have been searching thru various websites on how to tell if a 320 kbps mp3 file (cbr or vbr) really is a 320 kbps mp3 file (not converted from 128kbps). i have a two identical 320kbps mp3 files but from two different sources (one is directly converted from flac and the other directly from the internet). of course, i can't tell the difference using my ears, but when i use a software called spek that acts as a so-called 'good' spectrogram, u will be able to see the difference somehow. here is what i got:
 
 https://plus.google.com/115740564079867887953/posts/YRJ64KnVqjp
 
 
as you can see, there is a clear difference at the ceiling from 16khz to 20khz.  but i do not know what that means... 
and that is why i hope someone could tell me what is that difference, and if can, which one is better??!! thanks!! 

 

[streetdragon]

i notice that the FLac has more treble energy overall from the chart
im not too sure myself but this could mean 2 things

either the one directly from the internet has artifacts at 16khz and up
OR
the one from Flac has missing information from 16khz and up
(i suspect the first option though)
anyway 16khz is at the upper limit of human hearing, so it shouldn't bother you too much anyways

edit: oh crap i mixed up the 2 pictures! so sorry....

 

[stv014]

The "from internet" file lacks audio information above 16 kHz (the occasional small spikes above 16 kHz are probably there from clipping). 128 kbps MP3 typically uses a 16 kHz lowpass filter, while 320 kbps normally cuts off at 20 kHz, as you can see on the "from FLAC" spectrogram. So, your downloaded "320 kbps" file has indeed probably been converted from a lower bit rate lossy file.

 

[justcurious]

Thanks for the information!! i guess it's a pretty scary world where nothing is as it seems to be... i guess i could say that half my music library is full of low bit rate music files that eats up so much space because they are all encoded with 320kbps.. Thanks, anyway!! Cheers!

 

[justcurious]

sorry, guys.. i was hoping if you could tell if this is a 320 or not.. it might not be important but i just wanna know what you think??
 
https://plus.google.com/u/0/115740564079867887953/posts/3rxsUiiP8V7
 
although there is nothing to compare with, i hope that u could still tell if it is... it was downloaded directly from the internet, btw.. thanks!!