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Hydrogenaudio Forum => Uploads => Topic started by: Juha on 2010-03-15 17:34:05

Title: Periodical spike @ ~21401Hz
Post by: Juha on 2010-03-15 17:34:05
Hi!

This spike can be found on this track (Single Handed Sailor) only. It's there in few instances.

Is it the vinyl surface or could it just be some added signal.
If someone has this record in CD format, ... is it there as well?

(http://img682.imageshack.us/img682/8505/dsline.jpg)


Juha

EDIT: Oops! MOD, could you remove kilos from subject.
Title: Periodical spike @ ~21401Hz
Post by: evereux on 2010-03-15 18:24:47
Frequency Analysis (http://daefeatures.co.uk/images/HA/DireStraits_FrequencyAnalysis.png)

Spectral (http://daefeatures.co.uk/images/HA/DireStraits_Spectral.png)

I don't have the best tools for the job but I think these should answer your question. These are from an original CD release.
Title: Periodical spike @ ~21401Hz
Post by: pdq on 2010-03-15 19:04:34
Do these spikes occur once per revolution of the record, 33 1/3 times per minute?
Title: Periodical spike @ ~21401Hz
Post by: [JAZ] on 2010-03-15 19:38:03
@evereux:
Curious, that second one looks like if it had had a notchband filter applied precisely where Juha has found the issue. Could you try zooming in (into a span of two to three seconds at much) and see if the picture shows this effect in more detail?
Title: Periodical spike @ ~21401Hz
Post by: Juha on 2010-03-15 20:03:35
Do these spikes occur once per revolution of the record, 33 1/3 times per minute?


If I calculated it correctly, 56 spikes / second.

Here's picture of the whole track:

(http://img708.imageshack.us/img708/6370/dsline2.jpg)


Juha
Title: Periodical spike @ ~21401Hz
Post by: evereux on 2010-03-15 20:05:33
Here you go [Jaz]:

Spectral Zoom (http://daefeatures.co.uk/images/HA/DireStraits_Spectral2.png)
Title: Periodical spike @ ~21401Hz
Post by: greynol on 2010-03-15 20:09:51
Be careful with EAC's spectral view.

http://www.hydrogenaudio.org/forums/index....st&p=682929 (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=78111&view=findpost&p=682929)
Title: Periodical spike @ ~21401Hz
Post by: greynol on 2010-03-15 20:19:29
These periodic bursts are also visible in the time domain.

Watermarking or some artifact caused by resampling or format conversion?  I have no clue.
Title: Periodical spike @ ~21401Hz
Post by: greynol on 2010-03-15 20:32:51
I just checked my copy of this track from the SBM remastered CD and the bursts are there as well.  I had to resampled the clip in order to do a side by side comparison and it appears that the CD version plays slightly quicker and is out of phase.  To me this implies that bursts exist on the analog source that was digitized.
Title: Periodical spike @ ~21401Hz
Post by: Juha on 2010-03-18 08:33:06
Frequency Analysis (http://daefeatures.co.uk/images/HA/DireStraits_FrequencyAnalysis.png)

Spectral (http://daefeatures.co.uk/images/HA/DireStraits_Spectral.png)

I don't have the best tools for the job but I think these should answer your question. These are from an original CD release.


Looks like the 'noise' is present in CD version from start to end of this track (in my LP rip it's peridiocal) ... is it because of what [JAZ] suggests or is it because of analog technology is more 'lossy' and therefore I don't get it all showing up?

BTW, there's a Trial version of iZotope RX - http://www.izotope.com (http://www.izotope.com)


@evereux:
Curious, that second one looks like if it had had a notchband filter applied precisely where Juha has found the issue. Could you try zooming in (into a span of two to three seconds at much) and see if the picture shows this effect in more detail?


Would that be the best way to go to get rid of this 'noise' or just cut everything above ~20kHz? Possible issues ?

Juha
Title: Periodical spike @ ~21401Hz
Post by: greynol on 2010-03-18 11:02:43
Looks like the 'noise' is present in CD version from start to end of this track (in my LP rip it's peridiocal) ... is it because of what [JAZ] suggests or is it because of analog technology is more 'lossy' and therefore I don't get it all showing up?

The noise appears on my CD just as it does in your LP rip.  Evereux's CD is from an older mastering.
Title: Periodical spike @ ~21401Hz
Post by: [JAZ] on 2010-03-18 19:43:15
Be careful with EAC's spectral view.

http://www.hydrogenaudio.org/forums/index....st&p=682929 (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=78111&view=findpost&p=682929)


Indeed. It may mean it was lowpassed at 20Khz actually, and EAC mirrors that.