What is a good way to measure resonance up to 20Hz

[narud]

This seems to be true.

Increasing the effective mass will reduce the amplitude of the unwanted resonance, as the measurements show.

It is best to measure your system yourself.

In my experience, increased effective mass reduces the amplitude of resonance, however, sometimes it reduces it a lot, and sometimes it reduces it minimally.

The question is whether increased effective mass will not affect, in the long run, faster wear of the suspension parameters of the bracket?

i dont have any heavier headshells, so i added 4 grams of modeling clay to the headshell of the ptg. resonant peak went from 7hz to 6hz and the amplitude increased by a db.

 

[Balle Clorin]

Do you notice anything else changed in sound or behaviour? Tracking, wow. Sound?

 

[morillon]

in real life...
to what extent is this situation of "resonance" encountered?
but also what proportion is the "level" rating...
(without considering "the particular case"...very particular... )
;-))

 

[Quando]

i dont have any heavier headshells, so i added 4 grams of modeling clay to the headshell of the ptg. resonant peak went from 7hz to 6hz and the amplitude increased by a db.

Therefore, as I always say, you should measure your own system, and not rely on information found on the Internet. Information found on the Internet is not always true.

A difference of 1 dB is small, within the margin of measurement error, but any increase in amplitude is undesirable.

I wonder if reducing the effective mass, i.e. shifting the resonance to a higher frequency, would lower the amplitude of the undesirable resonance?
But it is not always possible to reduce the effective mass
You can also shift the resonance peak to a higher frequency by using a damping system, mechanical, viscous, electronic........ etc.

 

[Quando]

in real life...
to what extent is this situation of "resonance" encountered?
but also what proportion is the "level" rating...
(without considering "the particular case"...very particular... )
;-))

The phenomenon of unwanted resonance always occurs, it is undesirable but inevitable. We can only try to reduce the amplitude of this undesirable phenomenon.

I suggest referring the amplitude of unwanted resonance to the average volume.

I measure it with a test signal, sweeping the entire 20Hz-20 kHz band. This is quite a demanding test, the amplitude of unwanted resonance is usually in the range of 20-30 dB, below the RMS of the test signal.
Music records are not as demanding as the test signal. The level of the amplitude of unwanted resonance will be lower in relation to the RMS, usually in the range of 30-40 dB below.
Demanding, very demanding, may be records with organ music recordings, where some sounds may have an amplitude of 20 Hz, and sometimes lower.
Demanding will also be records with a high sound level, e.g. records for DJs, records played at 45 rpm. In these cases, very high demands are placed on the mechanical tonearm-cartridge system.

A large amplitude will also be generated by any off-center, crooked records, and these are the majority.

 

[morillon]

ah... this resonance must not be generated? the classic fork "8-12"was an approach, at the bottom, to avoid catching on the noise of the turntables, and "at the top" to move away from frequency problems that could be encountered on the support side but above all, except in special cases on the disc side essentially...
"accrochages bf" in french ;-)

of what order of magnitude is the level that could generate this resonance?
in real life...

quantifying these sources of resonance, and their level, is perhaps the first thing to observe... "the generator"
(see at the most basic, the famous blank tracks of our old test records designed for these uses perhaps ;-) )

no?

 

[Quando]

ah... this resonance must not be generated? the classic fork "8-12"was an approach, at the bottom, to avoid catching on the noise of the turntables, and "at the top" to move away from frequency problems that could be encountered on the support side but above all, except in special cases on the disc side essentially...
of what order of magnitude is the level that could generate this resonance?
in real life...

quantifying these sources of resonance, and their level, is perhaps the first thing to observe... "the generator"
(see at the most basic, the famous blank tracks of our old test records designed for these uses perhaps ;-) )

no?

Note that 8Hz-12Hz, that's a difference, about, in an effective mass of 20 grams, increasing the effective mass is easy, decreasing the effective mass is difficult.
You don't know, until you measure it, at what frequency the resonance amplitude will be the smallest, at 8Hz? or 12Hz?, maybe 9Hz etc or maybe 14Hz - Shure produced cartridges that had a resonance peak on the SME III 14 Hz arm, without damping.

 

[morillon]

Note that 8Hz-12Hz, that's a difference, about, in an effective mass of 20 grams, increasing the effective mass is easy, decreasing the effective mass is difficult.
You don't know, until you measure it, at what frequency the resonance amplitude will be the smallest, at 8Hz? or 12Hz?, maybe 9Hz etc or maybe 14Hz - Shure produced cartridges that had a resonance peak on the SME III 14 Hz arm, without damping.

sme 3, light arm, adapted to its era and the typicals cartdriges this one... seems a bit too much for the shure you are referring to(?)
...
you just have to look elsewhere for cartridge or tonearm in this case

 

[Quando]

sme 3, light arm, adapted to its era and the typicals cartdriges this one... seems a bit too much for the shure you are referring to(?)
...
you just have to look elsewhere for cartridge or tonearm in this case

 

[morillon]

? i can t see images..... "not found"

 

[Quando]

? i can t see images..... "not found"

 

[Quando]