Rumble from Turntable Bearing?

[Thomas_A]

If anyone wants to read a bit more about low frequency effects,

Billie Jean dance

I found a video on AK regarding arm/cartridge ”dance” while playing the highly modulated Billie Jean on M Jacksons album Thriller. I checked my own and it does the same. My guess is that this would be fixed if the horizontal Rf would be low, as would be expected if you use an arm with much...

www.audiosciencereview.com

And you don't need Michael Jackson to see the dance; it happens with classical music as well.

Recommendations for digitizing vinyl

I really do not understand the point of using time money and effort to digitise hundreds or thousands or records. Get Tidal and stream the music if you want it digital,you can even burn a USB/CD from steaming and use it in the car. Play the vinyl records when you want to listen to vinyl. Vinyl...

www.audiosciencereview.com

 

[Thomas_A]

It is a function of the way any cartridge works so is unavoidable with any arm.

The principle yes, but arms can show quite different results in exciting those resonances.

RB330:

Moerch DP-8:

 

[EJ3]

It is a function of the way any cartridge works so is unavoidable with any arm.

Thank you.
I wasn't thinking that it might be totally unavoidable but I was thinking that it might be minimized.

 

[Waveform Fidelity]

The picture in my original post shows it at around -30db

And no practical speaker will create, nor any human ear detect these sub-sonic sounds, but nevertheless its been an interesting intellectual debate. BTW have you every thought about the engineering challenges of getting the stylus to stay inside the record groove? Not to mention how that hard stylus wears down the soft vinyl grooves over time? As a young engineer at the time, me and my friends could not wait to see the back of Vinyl records to be replaced by the superior sounds of CD’s.

 

[NTK]

And no practical speaker will create, nor any human ear detect these sub-sonic sounds, but nevertheless its been an interesting intellectual debate. BTW have you every thought about the engineering challenges of getting the stylus to stay inside the record groove? Not to mention how that hard stylus wears down the soft vinyl grooves over time? As a young engineer at the time, me and my friends could not wait to see the back of Vinyl records to be replaced by the superior sounds of CD’s.

Shure did 50 years ago.
The 2 curves showed the trackabilities of V 15 III and V 15 IV mounted on an SME 3009 arm. The dips in the curves were the effects from the resonance of the spring-mass system due to the cartridge compliance and tone arm effective mass.

Source: https://service.shure.com/s/article...technical-seminar?language=en_US&region=en-US

 

[Frank Dernie]

Thank you.
I wasn't thinking that it might be totally unavoidable but I was thinking that it might be minimized.

Tracking error is eliminated by a parallel tracker but inaccurate low bass is inherent because it only starts "measuring the groove" accurately once the cartridge body becomes effectively a stator and that is at around 2x Fn - but varies slightly depending on damping.

 

[Frank Dernie]

The principle yes, but arms can show quite different results in exciting those resonances.

RB330:

Moerch DP-8:

Yes both arm mass and damping and cartridge compliance and damping influence the frequency, amplitude and decay of the resonance, but it is still results spurious output from the cartridge related to those parameters NOT music on the disc.

One can change the nature of the spurious output but not prevent it.

It is an inevitable side effect of the way the transducer works and is inherent there is no "solution".

A high pass filter is needed for accurate reproduction since the flank of the resonance is usually in the audible frequency range yet not accurate.

 

[AndyMorris]

And no practical speaker will create, nor any human ear detect these sub-sonic sounds, but nevertheless its been an interesting intellectual debate. BTW have you every thought about the engineering challenges of getting the stylus to stay inside the record groove? Not to mention how that hard stylus wears down the soft vinyl grooves over time? As a young engineer at the time, me and my friends could not wait to see the back of Vinyl records to be replaced by the superior sounds of CD’s.

While we cannot hear these sounds, getting rid of them 'up-stream' has advantages, especially in an audio restoration framework:

• It reduces visual noise in editing software
• It may remove signals that would damage loudspeakers

I tend to agree that CD's can produce superior sounds. They can also be remastered to be compressed, have spurious stereo added or just messed around with. They tend to have artwork that is cramped, often unreadable and lack the intent of the artist who worked for a 12" or gatefold sleave.

I love the idea that my recording is as close as possible to the experience the artists had when they said 'that'll do".

Personally, the process of find some treasure in a record fair, bringing it home, capturing and restoring the sound has a massive Ikea Effect. That might not be rational, but the reason I do all that is that I enjoy my emotional connection to the music. Anything that adds to that connection is good for me,

 

[Thomas_A]

Yes both arm mass and damping and cartridge compliance and damping influence the frequency, amplitude and decay of the resonance, but it is still results spurious output from the cartridge related to those parameters NOT music on the disc.

One can change the nature of the spurious output but not prevent it.

It is an inevitable side effect of the way the transducer works and is inherent there is no "solution".

A high pass filter is needed for accurate reproduction since the flank of the resonance is usually in the audible frequency range yet not accurate.

Problem is that the high pass filter in the preamp does not change anything happening at the cartridge/stylus. It is quite evident that cartridge/arm move around to music beats and excite LF resonances; the ideal is to remain steady. One can just look at the cartridge body moving to the beats as well as measure it.

 

[Frank Dernie]

Problem is that the high pass filter in the preamp does not change anything happening at the cartridge/stylus. It is quite evident that cartridge/arm move around to music beats and excite LF resonances; the ideal is to remain steady. One can just look at the cartridge body moving to the beats as well as measure it.

Yes but this is inevitable. All impact type excitations are wideband so excite resonance, it is one of the bits of physics that allows us to do modal analysis in vibration research using an instrumented hammer and a handful of sensors.
It is real, explained by the physics, and is one of the most serious weaknesses of the whole concept of the disc playing music system which has come our way and was hard wired into it over a century ago.
Using a damped arm pivot (one of my arms has a pivot damper capability built in) or a Townshend trough may help in as much as the amplitude will be reduced which will have the benefit of keeping the transducer in the more linear part of its magnetic circuit. But the cartridge will still not be in the frequency range where it is dynamically static.
Analogue tape has problems with linearity in the bass too. If you want accurate bass you need CDs

 

[Frank Dernie]

I love the idea that my recording is as close as possible to the experience the artists had when they said 'that'll do".

You realise you are less likely to get that from an LP than a CD don't you?

 

[AndyMorris]

You realise you are less likely to get that from an LP than a CD don't you?

True if no one has messed with the mastering.

I still get a thrill from listening to the same grooves that my late father did, as a teenager, 78 years ago.

 

[Frank Dernie]

True if no one has messed with the mastering.

I still get a thrill from listening to the same grooves that my late father did, as a teenager, 78 years ago. View attachment 492994

The sad thing is the compressing of dynamic range and raising average level gives the impression of more dynamics and punch, not less, because it is louder and is almost always exactly "when the artist said that'll do" nowadays.

Old discs had also had to be manipulated by reducing dynamic range in order for them to be able to be cut (I worked in the industry 50 years ago). The one you illustrate too, probably, by the disc lathe operator riding the volume control.

Certainly I also believe a minimum of manipulation is good but most - if maybe not all - 78s and LPs were manipulated by the cutting engineer.
Probably the least manipulated recordings one could ever buy were early CDs before much electronic dickery became possible/easy.

OTOH if you want to digitise old 78s or LPs you are stuck with the shortcomings of the record playing device which was imperfect in concept from day one, I'm afraid.

FWIW I gave up digitising my LPs, firstly I had hundreds of them and it was horrendously time consuming to do well - so now I just play the record whenever I want to listen to it

I still have 4 record decks - bonkers.

 

[Balle Clorin]

That's interesting. I'm thinking of ways to see if that is so.

Just record any silent part of A record or A steady tone, and look at the waveform vs time in an audio software. , see what Thomas_A did , zoom in enough and you can se the resonance.

 

[Thomas_A]

Yes but this is inevitable. All impact type excitations are wideband so excite resonance, it is one of the bits of physics that allows us to do modal analysis in vibration research using an instrumented hammer and a handful of sensors.
It is real, explained by the physics, and is one of the most serious weaknesses of the whole concept of the disc playing music system which has come our way and was hard wired into it over a century ago.
Using a damped arm pivot (one of my arms has a pivot damper capability built in) or a Townshend trough may help in as much as the amplitude will be reduced which will have the benefit of keeping the transducer in the more linear part of its magnetic circuit. But the cartridge will still not be in the frequency range where it is dynamically static.
Analogue tape has problems with linearity in the bass too. If you want accurate bass you need CDs

Not only damping but mass would help laterally where the bass is recorded. Lateral disturbance from records are mostly 0.55-2.2 Hz so keeping the fundamental tonearm/cart resonance at say 5-7 Hz would give 2xRf at 10-14 Hz. Still far from Redbook having down to DC but good down to 20 Hz.

 

[DVDdoug]

I love the idea that my recording is as close as possible to the experience the artists had when they said 'that'll do".

The artist doesn't usually get much say in the matter. ...Unless they are a "bedroom artist/producer", or someone with many years of success behind them so they can produce their own recordings or dictate the terms of their contract.

"Traditionally" the producer is responsible for the overall production and sound but I'm not sure who gives the final approval of the master... Somebody at the record company. The artists may not be around for the final mixing and they are rarely present during mastering. I don't believe the producer is normally involved in mastering either.

I read about The Doors being surprised when the song Riders On The Storm was released with storm/rain sound effects. And Waylon Jennings was unhappy when Violins were added (after he was finished in the studio and no longer around) to "sweeten" his recordings. He liked the "raw" sound.

 

[Frank Dernie]

Not only damping but mass would help laterally where the bass is recorded. Lateral disturbance from records are mostly 0.55-2.2 Hz so keeping the fundamental tonearm/cart resonance at say 5-7 Hz would give 2xRf at 10-14 Hz. Still far from Redbook having down to DC but good down to 20 Hz.

But liable to be excited more by off centre and warp.
The normal recommendation for a least problematic arm/cartridge resonance is to aim for around 12Hz.
Basically record players are pretty poor at bass due to the conceptual design and we are stuck with it.

This has been a point of discussion for about 55 years of my experience and younger enthusiasts re-discover it from time to time. There is a great tendency to apply static reasoning to a dynamic system which leads to misunderstanding and this is even amongst some well marketed manufacturers...

I realise it is hard to get ones head round. My old boss who was head of R&D when I was head of the Noise and Vibration research section always said I see the maths but I can't get my head round it, dynamics isn't something many people have much of a feel for IME.

 

[Doodski]

But liable to be excited more by off centre and warp.
The normal recommendation for a least problematic arm/cartridge resonance is to aim for around 12Hz.
Basically record players are pretty poor at bass due to the conceptual design and we are stuck with it.

This has been a point of discussion for about 55 years of my experience and younger enthusiasts re-discover it from time to time. There is a great tendency to apply static reasoning to a dynamic system which leads to misunderstanding and this is even amongst some well marketed manufacturers...

I realise it is hard to get ones head round. My old boss who was head of R&D when I was head of the Noise and Vibration research section always said I see the maths but I can't get my head round it, dynamics isn't something many people have much of a feel for IME.

The voice of reason and experience. Thanks Frank.

 

[Thomas_A]

But liable to be excited more by off centre and warp.
The normal recommendation for a least problematic arm/cartridge resonance is to aim for around 12Hz.
Basically record players are pretty poor at bass due to the conceptual design and we are stuck with it.

This has been a point of discussion for about 55 years of my experience and younger enthusiasts re-discover it from time to time. There is a great tendency to apply static reasoning to a dynamic system which leads to misunderstanding and this is even amongst some well marketed manufacturers...

I realise it is hard to get ones head round. My old boss who was head of R&D when I was head of the Noise and Vibration research section always said I see the maths but I can't get my head round it, dynamics isn't something many people have much of a feel for IME.

I would say that the usual 8-12 Hz is based on a conventional tonearm and the warp f. In reality it is not so. Warp and record eccentricity numbers are different, which make the placement of resonance accordingly, laterally and vertically. A vertical Rf of 15 Hz and lateral of 8 Hz more ideal than having it at 11 Hz both ways.

 

[Balle Clorin]

The thing many are not aware of is that you do not need a warp of the same frequency as the resonance to trigger the resonance. A disturbance like a sudden drop or bump is like an impulse it “contains “ many frequencies… this will be enough to trigger the resonance.