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Original Flac spectrum compare with 320, 256 till 64 kbps

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amit11

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Hi Friends,

I had read somewhere in the forum about spek software for viewing the audio spectrum.

Out of curiosity I tried it on various bit rate files and was amazed to see the differences.

From original flac to 320 kbps till 64 kbps, all converted from the original flac, I have put the images from the software, side-by-side to get a view for comparison.

So just thought to share with you.

Regards,
Amit.
 
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Maxprocrj

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Interesting FLAC & 320 KBPS spectrum is showing almost identical....
 

jls001

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What is the lost component as compression is increased? Amplitude or frequency? Or something else?

Good experiment, BTW :)
 

keith_correa

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It depends a lot on what the source recording contains. Can you do a compare of a 20-20 frequency sweep?
 

Thad E Ginathom

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What is the lost component as compression is increased? Amplitude or frequency? Or something else?
Yes, yes, and, I guess, yes!

The principle is that sounds that won't be perceived are removed. The genius involved (assuming success ;)) is that it adds human perception to the demands of data compression.

Whether we like it or not, that is clever!

About the detail, I am not that technical, but I believe that there is a certain hard limit to upper frequencies, and the pictures confirm that.

I'm no expert at reading those spectra either, but, as a novice, it looks to me that most of the dynamism of the music is preserved all the way down to 128 (which is not a claim that it would sound identical) with a marked step down to 64.

Thanks for the experiment amit :)
 
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shkumar4963

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Looks like Spotify premium got it right. All their recordings are at 320. I have compared FLAC from tidal with 320 from Spotify and to my ears and with my music system I can not tell them apart.
 

keith_correa

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Amit, were these encoded in CBR or VBR?
 
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Thad E Ginathom

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Dynamism??!! What does it constitute of?
Bicycles used to have them, powering the front light, but then the front light was done away with. Cars used to have them before alternators. Oh wait, didn't I say dynamo? no...

I think I meant Dynamics :eek: :eek:
 

Nikhil

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Great software! Thanks for sharing.

It's hard to make out anything unless you see what is being scaled on the X & Y coordinates of the graph. After installing the software I understood that the software does a FFT analysis and giving a frequency spectrum mapped on the X axis with time on the Y axis. The colour represents the dB level as shown on the scale on the right.

I ran a scan of two hi res DXD files (basically 24 bit 352.8kHz PCM) and it was interesting. Spek does not work on DSD files unfortunately. I've commented on where the audible section (20Hz to 20kHz) is down at the bottom. My guess of what's going on is that all the noise is dumped into the high frequency region > 80kHz.



 

sound_cycle

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Hi

As will be evident from the question below, I have a PhD on the subject, so please bear with me.

I have this notion that there is something in my sound output that is not quite right.

And so I want to be able to play a flac (on fb2k) , and get the output that is being sent to the DAC (optical over spdif), somehow on to a file and then compare the two ie original and captured files using something like spek.

Is that possible or are there easier situations ?

The basic idea is to figure out if there is indeed actually something I am hearing. I ***think*** there is because when i play the CD that was the source of the flac my brain wants me to believe the sound is better.

ciao
gr
 

arj

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Hi Friends,

I had read somewhere in the forum about spek software for viewing the audio spectrum.

Out of curiosity I tried it on various bit rate files and was amazed to see the differences.

From original flac to 320 kbps till 64 kbps, all converted from the original flac, I have put the images from the software, side-by-side to get a view for comparison.

So just thought to share with you.

Regards,
Amit.
HI, do you have any high rez images of these. at least for flac and 320
Even with this image magnified, the top end of the spectrum (is it frequency on the y axis ?? ) , seems quite different between flac and 320
 

amit11

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@arj

Thats right, frequency on the Y-axis and time on the X-axis.
As you rightly pointed, FLAC and 320 do have some visible difference on the top end when we see it closely.


Attaching 2 files. One for FLAC and another for 320. Visiting hifivision after a few months....catching up with old threads.

Regards,
Amit.
 

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arj

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thanks Amit..from the images I presume the first one is FLAC since the Top frequencies are more filled out ? i presume this is because of higher harmonic content. Usually mp3s remove out content which may not be "Hear-able" and i believe that includes a lot of Harmonic content
 

amit11

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Yes...first one is flac.

And different mp3 decodes do differently. Apart from cutting out the high frequencies straight away, they might also be affecting other frequencies in one or the other way, which might be noticeable straight away or less noticeable when listening.
 

alpha1

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Hi

As will be evident from the question below, I have a PhD on the subject, so please bear with me.

I have this notion that there is something in my sound output that is not quite right.

And so I want to be able to play a flac (on fb2k) , and get the output that is being sent to the DAC (optical over spdif), somehow on to a file and then compare the two ie original and captured files using something like spek.

Is that possible or are there easier situations ?

The basic idea is to figure out if there is indeed actually something I am hearing. I ***think*** there is because when i play the CD that was the source of the flac my brain wants me to believe the sound is better.

ciao
gr
1. The first thing to do will be to ascertain that whether you are indeed hearing the difference between CD and FLAC.
Since you have foobar, it is as easy as twiddling thumbs. Use the ABX comparator plugin (foo_abx I think) in the foobar and load the raw and flac files.

2. Next will be the difficult task of doing ABX of DAC output vs CDplayer output.

Steps 1 and 2 are totally non related to each other.
 

Amarendra

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Does this mean that we have been unnecessarily fussy about flac vs mp3 at 320 kbps ? Just asking since the graph looks almost identical.
 
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