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Unwanted resonance measurement in the range of 0-20 Hz

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Quando

Quando

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Unwanted resonance measurement in the range of 0-20 Hz
Test signal sweeping the 20Hz-20 kHz band, track 1 and track 2 Side A Clearaudio CA-TSR-1007 disc
The test signals measured (without the pilot signal and with the silence removed) are exactly the same ones that are used to measure the frequency response of the cartridge in the Spyder program.
The left channel separately, the right channel separately.
This is my first measurement made in this way, so I don't know if the amplitude level is high or low.
I will be able to confirm this when I make further measurements, including measuring the frequency of the turntable cartridge.

The amplitude level of the unwanted resonance is referenced to the RMS of the signal measured using Audacity, i.e. by what value the peak of the unwanted resonance is below the RMS of the sample. The higher the value, the better.

Ortofon Kontrapunkt b (New)
Technics SL-1200GR2 turntable (orginal headshell)
Needle pressure: 2.5 grams
Anti-skating: 3 grams
SUT: Ortofon T-30 (12 Ohm)
NAD 1155: Phono MM (100pf)
Capacitance of cables to Ortofon T-30: 140 pF
Capacitance of cables from Ortofon T-30 to NAD 1155: 40 pF
Sound card: Focusrite Clarett+ 2Pre USB
WAV: 16 bit-96kHz

Left (11Hz) 18,17 dB
Right (12Hz) 18,96 dB

Plot_Left.jpg


RMS_Left.jpg


Plot_Right.jpg


RMS_Right.jpg
 
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This is why better vinyl preamps have built-in rumble filter. Resonance is to some degree dependent on cartridge, partiall the turntable, partially tonearm.

With Audacity it is easy to apply highpass filter to the digitized copy.

NAD Cooder Little Sister spektri.png NAD Cooder Little sister high pass 24dB@30Hz spektri.png
 
Juhazi said:
This is why better vinyl preamps have built-in rumble filter. Resonance is to some degree dependent on cartridge, partiall the turntable, partially tonearm.

With Audacity it is easy to apply highpass filter to the digitized copy.

View attachment 398556 View attachment 398555
Click to expand...

Resonance in the range up to 20Hz, which usually has a high amplitude, depends, as you wrote, on many factors, including the selection of compliance relative to the effective mass, but also on the eccentricity and other distortions of the vinyl record. The better all these elements are, the lower the amplitude level of the unwanted, but inevitable, resonance will be.

Some preamplifiers or amplifiers had a built-in filter, called differently, for example INFRA, a steep filter set at a frequency of about 15HZ, with, with a drop of about 12dB/octave, which was intended to reduce the amplitude level of the unwanted resonance.

Yes, of course, in Audacity, in the case of digitization, you can set the highpass filter, at different frequencies, there is a wide range of amplitude reduction to choose from. You can also do the opposite, set a low-pass filter to check what you are reducing, whether, for example, you are not influencing the music signal too much. There are many possibilities.

So far, the differences in the measurements are small, because the record with the test signal is straight, the turntable cartridges, the turntable, the tonearm, are of good quality and are in good condition. The susceptibility of the cartridges to the effective mass gives a resonance peak around 10 Hz, so it is well matched.
This is not always the case.
 
The low frequency resonance screws up things when adjusting azimuth/crosstalk too. To get the best azimjuth adjustmet low pass filter should be on and preferably RIAA
disabled too

1728819046315.png

1728818987473.png


The plot below shows how the low frequenct resonance pollutes relative to some test signals on the same test record. 440Hz cross talk test, 1khz reference test, white noise track( not very even WN, cartridge is not that as bad ast it looks here). With RIAA engaged it gets even worse, by 20db!!!. Keep that rumble filter on!!
EDIT: Added Equalised CA TRS-100t test record sweep signal in red
1728823651679.png
 

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Balle Clorin said:
The low frequency resonance screws up things when adjusting azimuth/crosstalk too. To get the best azimjuth adjustmet low pass filter should be on and preferably RIAA
disabled too

View attachment 398577
View attachment 398576

The plot below shos how the low frequenct resonance pollutes relative to some test signals on the same test record. 440Hz cross talk test, 1khz reference test, white nouse track( not very even WN, cartridge is not that as bad ast it looks here). With RIAA engaged it gets even worse, by 20db!!!. Keep that rumble filter on!!
View attachment 398579
Click to expand...
given the frequencies concerned, it may be possible to intelligently observe the amplitude of movements/frequency using video captures on a dedicated sweep... without necessarily having to use high-speed cameras.
;-)
 
Different resonance for L/R comes because of 90deg difference in orientation of stereo vinyl modulation. Antitracking force might be wrong too.

How to pack a stereo signal in one record groove

phono, analog, vinyl, recorder, single, maxi, disc, dubplates, cut, dubrecord, record, directmastering, pressing, pressung, schallplatten, herstellung, einzelplatten, master, lathe, audiodiscs
www.vinylrecorder.com
 
Your thoughts are interesting and definitely worth reading.
However, until we measure the resonance level with the same test signal in the same way, this will be one big garbage dump.
 
Here with the Equalised CA TRS-1007 sweep signa in red..
1728823628664.png



Including the 1000hz pilot/reference tone in front, ruble filter probably active here
1728823801505.png

1728823850594.png



Another cartridge and arm, do not think low filter is active here, butt RIAA may cut off some below 20hz default. 1/48 smoothing for clarity
Effect of low freq/rumble filter is indicative even if it is not the same cartrideg

1728824478741.png


Very common cheap cartridge on a cheaply made DD from 70's
1728825632867.png
 

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morillon said:
you just want to repeat here what you did there...?
you should rather take advantage of this to look at antiskating, for a change....
hihi
;-)
Click to expand...
The problem is that on such forums, everyone knows better and everyone does it differently.
There is no point in wasting time just to create another garbage.

Besides, in the topic of measuring phonograph cartridges I was blocked because I wrote that the results of these measurements should not be taken seriously.
All you need to do is set the cartridge a little differently and you will get the correct result, but the measurement values will be different.
So these measurements should be treated solely as good fun.

The author of the program got offended :)
Funny.

Anti-skating is ok.
 
Quando said:
The problem is that on such forums, everyone knows better and everyone does it differently.
There is no point in wasting time just to create another garbage.

Besides, in the topic of measuring phonograph cartridges I was blocked because I wrote that the results of these measurements should not be taken seriously.
All you need to do is set the cartridge a little differently and you will get the correct result, but the measurement values will be different.
So these measurements should be treated solely as good fun.

The author of the program got offended :)
Funny.

Anti-skating is ok.
Click to expand...
you don't answer my question..and better...you seem to explain that it is stupid to "create another trash"....surprising I don't understand...
isn't it simpler to just invite those interested to dialogue with you to just join the discussions on the other forum?...

anti-skating side I don't think so...it's an important subject that your "dada" seems to have eclipsed....
;-)
(even if a real problem...without a real solution in real life...becomes more manageable and anticipable in our simplified measurement approaches...)
 
morillon said:
you don't answer my question..and better...you seem to explain that it is stupid to "create another trash"....surprising I don't understand...
isn't it simpler to just invite those interested to dialogue with you to just join the discussions on the other forum?...

anti-skating side I don't think so...it's an important subject that your "dada" seems to have eclipsed....
;-)
Click to expand...

I'll manage on my own ;)

I won't waste any more time here....
 
Quando said:
I'll manage on my own ;)

I won't waste any more time here....
Click to expand...
well no...you are already on another very busy forum...not alone therefore..or..questions arise at your level ;-)))
 
Quando said:
The author of the program got offended :)
Funny.
Click to expand...

The "author" of the program wasn't offended in the slightest and, further, had nothing to do with your thread time-out.
 
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