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Axiom05

Spectrogram Help: Poulenc's Organ Concerto

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I am hoping to get some help interpreting the attached spectrogram. It is from a recording of Poulenc's Organ Concerto made at 24 bit/88.2 KHz resolution. I assume that the line across the spectrum at just under 16 KHz is the whine from the organ blowers. I have seen similar results from other organ recordings. What I don't understand is the "haze" between about 30 KHz and 40 KHz that is across the entire recording (this I have not seen in other organ recordings). Is this some kind of ultra sonic noise? Is this anything to be concerned about? Obviously this is not present in a spectrogram of the CD rip of this recording. TIA.

 

Poulenc Organ Concerto.png


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A 16kHz whine often indicates that there was a television monitor in the room when the recording was made. The ultrasonic noise would come from DS modulation. It is likely that the signal went through a DSD64 stage at some point.

 

 

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A 16kHz whine often indicates that there was a television monitor in the room when the recording was made. The ultrasonic noise would come from DS modulation. It is likely that the signal went through a DSD64 stage at some point.

 

Thank you for your response. The CD that I have is HDCD encoded so I would think that the original master was PCM. I guess it is possible that the PCM file was converted to DSD64 for SACD release and that the DSD64 was used to create the 24/88 file. If so, I wish I knew why the original PCM file was not used? BTW, the spectrogram of the 24/88 file came from Primephonics website. I am not sure that I see any reason to replace my CD rip with this download.

 

Cheers!


(MPD/Rigelian), Sonore ultraRendu, Sonore ultraDigital, Ayre QX-5 Twenty, Ayre KX-5 Twenty, Ayre VX-5 Twenty, Revel Ultima Studio2, Iconoclast speaker cables & interconnects, RealTraps acoustic treatments

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A 16kHz whine often indicates that there was a television monitor in the room when the recording was made.

Yes, we need to be specific there - this is CRT based television monitor. Some modern LCD do not generate such noise in that region (more often LCD generates something from switching power supply, ca 62kHz for example).


Sorry, english is not my native language.

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Thank you for your response. The CD that I have is HDCD encoded so I would think that the original master was PCM. I guess it is possible that the PCM file was converted to DSD64 for SACD release and that the DSD64 was used to create the 24/88 file. If so, I wish I knew why the original PCM file was not used? BTW, the spectrogram of the 24/88 file came from Primephonics website. I am not sure that I see any reason to replace my CD rip with this download.

 

I should add that the original CD release was in 2001 from Linn. The CD booklet gives no indication what the original recording format was.


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I am hoping to get some help interpreting the attached spectrogram. It is from a recording of Poulenc's Organ Concerto made at 24 bit/88.2 KHz resolution.

 

 

The CD that I have is HDCD encoded so I would think that the original master was PCM.

 

 

I guess it is possible that the PCM file was converted to DSD64 for SACD release and that the DSD64 was used to create the 24/88 file. If so, I wish I knew why the original PCM file was not used?

 

The spectrum looks like DSD to PCM converted file, where noise was cut upper 42 kHz.

 

Studio processing of DSD is implemented as PCM, as far as I know.

 

If suggest what original master is PCM (very probably), I don’t know reasons for convert it to DSD and back.

 

May be there was used enhancer like [PCM > analog > DSD > PCM]. In this case it may be considered as subject of audio mastering art.

 

If the noise don’t cause discomfort to you, don’t worry about it.

 

As experiment, you can cut spectrum over 20 kHz and compare sounding of original and cut ones.

 

If there no difference, it is mean what intermodulation distortions is low and ultrasound noise is not matter for your system.


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I should add that the original CD release was in 2001 from Linn. The CD booklet gives no indication what the original recording format was.

On such an old recording, perhaps the most likely explanation for what we're seeing is that the the original ADC ran internally at 64x, 1-bit, and output PCM with some observable DS modulation noise. In that case, the original master format could be 24/88 that looks converted from DSD, even though DSD was never recorded. This isn't a possibility that I considered when I assumed that I was looking at a fairly new recording – almost all modern ADCs are going to run at a much higher rate internally.

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Thanks for the replies everyone! Your comments have been instructive and helpful.

 

On such an old recording, perhaps the most likely explanation for what we're seeing is that the the original ADC ran internally at 64x, 1-bit, and output PCM with some observable DS modulation noise. In that case, the original master format could be 24/88 that looks converted from DSD, even though DSD was never recorded. This isn't a possibility that I considered when I assumed that I was looking at a fairly new recording – almost all modern ADCs are going to run at a much higher rate internally.

 

This does make some sense as everyone was touting the use of "Bit Stream" technology. I guess the HDCD encoding could have been done at the 24/88 to CD conversion stage. At any rate, I am clearly over analyzing this whole thing (usually not a good thing when it comes to recordings). I just need to decide whether the high res. download would provide a sonic advantage over my CD rip.


(MPD/Rigelian), Sonore ultraRendu, Sonore ultraDigital, Ayre QX-5 Twenty, Ayre KX-5 Twenty, Ayre VX-5 Twenty, Revel Ultima Studio2, Iconoclast speaker cables & interconnects, RealTraps acoustic treatments

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I just need to decide whether the high res. download would provide a sonic advantage over my CD rip.

 

Hi-res may give advantages in complex with your software+hardware only.

 

But almost nobody know how it work (except the developers). So only testing need there.


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On 25/01/2017 at 6:18 AM, audiventory said:

If suggest what original master is PCM (very probably), I don’t know reasons for convert it to DSD and back.

 

Marketing?

Linn isn't a mainstream label, it caters mainly to audiophiles.


"Science draws the wave, poetry fills it with water" Teixeira de Pascoaes

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The 16 kHz tone is likely from a CRT as those were still common it 2001. It could also be something else.

 

The noise is from a sigma-delta modulator somewhere in the production chain. Could be the recording ADC, or perhaps this is a conversion from the SACD release. That sounds pointless, but these things do happen.

 

On 25/01/2017 at 12:10 PM, Axiom05 said:

I just need to decide whether the high res. download would provide a sonic advantage over my CD rip.

I'd say there's no reason to buy this again. The spectrogram shows a little content above 22 kHz, but it will mostly be drowned out by that noise (not that either is audible). The exception would be if the CD sounds bad in some way due to a shoddy down-conversion. I wouldn't expect that from Linn though.

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