Can spectrogram lie about audio quality?


#21

I've stopped using Spectro on the account of it not being able to utilize my resolution of 1440p- it is just to small on my screen

I've seen such data many times and was suspecting what you just described- a lossy mastering


One symptomatically case [and the final proof to my thesis] was that of music from the 1982 movie "Blade Runner", released as late as in 1994. Wanting to upgrade it from some old MP3s I downloaded one set of FLACs- and they were stopping at ~20+ kHz. So I search for another source- there were the same. So I went to my closet, took out the box with CDs, ripped the original disc [EastWest Records America 4509-96574-2] with Audiograbber on maxed out settings and there it was- a blank space above 20 kHz. Here is an example, the song "One More Kiss, Dear":




And just to make sure I checked the 2007 Special Edition of that score, which on disc 3 contains additional music [not the original compositions]. Here is the track "Up And Running", which samples heavily that "One More Kiss, Dear" song:

It is quite masked with all the new sounds with which the layered the sampled original, but for me to spot such a cut off line is no longer a problem- if I see something like that then I suspect that something like a lossy samples are the culprit. And also comparing different tracks from the same album can tell a lot. That is most evident with OSTs, were you have music from different sources


As for Fakin' The Funk. Here are spectrograms made by it for those same file of "One More Kiss, Dear" and "Up And Running"


For sure I would never spot the issues of samples in the "Up And Running" as I did in Spek. And the "One More Kiss, Dear" was reported on the list of files as a positive [green thumb up]- and I checked the settings [aggressive, report above 256, analyze entire]. So it seems that although FTF has easy interface and can be used for mass check-up, the results may be incorrect


#23

What I wanted to write was

It is quite masked with all the new sounds that are layered over the sampled original, but for me to spot such a cut off line is no longer a problem

[I cannot edit this post no more and I have already flagged this for moderation in hopes of correcting my mistake]


#24

On a side note but in relation to issue of checking frequencies:


If anyone wants to checking specific frequencies then you can use Audacity. Under the

Effects > Equalization...

the user can quite precisely wipe out frequencies at any range. Unlike in may other software equalizers, which usually stop at 16 Khz with manipulation of sound, Audacity wipes out at levels as high as the specifications of a given file are [e.g. 96 Khz]. And by that manipulation [in other equalizers] I mean adjustments / tempering and by wiping out [in Audacity] I mean going even as far a as completely eradicating any data

So if you want to check your ability to hear high frequencies and know what really you are missing when listening to CD-quality instead of a digital 96 Khz version of the same recording, then you can wipe out everything below 22 Khz and hear for yourself: [SPOILER ALERT] absolutely nothing


#25

I think that the 96 kHz is the sampling rate.
If you want to sample a given signal, you have to have a sampling rate at twice the maximum frequency of that signal that you want to convert into numeric values.
So if you want to sample 20 kHz, you should use a sampler with 40kHz sampling rate.
If you have a stereo signal then you need that sampler for both channels - so you need a 80 kHz sampling clock.
The 96 kHz not necessarily mean that you find an audio signal with 96 kHz in the file, it tells about the technology used when sampling the original signal.
See also


#26

You are probably right

But I am referring to marketing schemes when the music industry tries to sell the same old music only because it was remastered and is being sold in XXX Khz; and not mentioning, that it sound different [not always better may I add] because it was mixed from scratch or at least somehow filtered


https://www.youtube.com/watch?v=xH8I0LUjrqw - two guys sit in a car with an unknown hardware setup and talk about how great it sounds, with its greatness coming supposedly only out from a file used and not the hardware. And then the video talks also about feet of water, when trying to diminish CD-quality... hilarious, simply hilarious