Effective Mass of SME 3009 S2 Improved, anyone tested it?

[Blue Shadow]

The mass of the removable headshell (S2) version of the improved 3009 is listed all over the world as 9.5 grams. OK, but wait there is more.

The SME sales sheet for the 3009 Improved tonearms shows both the 3009 Series II Improved (the non-detachable headshell version) and the S2. The first two paragraphs talking about the arms state that the S2 Improved is a 12.5 gram effective mass arm and the Series II Improved is a 9.5 gram effective mass tonearm.
Side One: http://www.vinyl-lebt.de/SME/Technical/SME_Imp.jpg
Side Two: http://www.vinyl-lebt.de/SME/Technical/SME_Imprueck.jpg

For this reason, I'm looking for someone that has verified the effective mass of one of these tonearms with a proper test record and a cartridge of known compliance, generating an output peak at a frequency that would allow determination of the effective mass of the arm.

Is the Entire Planet using the wrong effective mass for the Improved SME arms or did SME produce a misprinted sales sheet? It is even shown on the site where the sales sheet is that the effective mass is the lower 6.5/9.5 numbers. http://www.analogue-classics.com/html/sme_3009___3012.html

It sure would be very helpful to know the truth as these are very popular and for separate components, ubiquitous tonearms. I know that the Improved meant lower mass as that was the popular way to go back then and even SME went there with the 3009 Seires III.

 

[bob06]

I believe the 3009 improved non removable headshell 6.5 The 3009 improved with removable headshell 9.5 Then the older style 3009 SII is 12.5

 

[KentTeffeteller]

Which is correct.

 

[fiddlefye]

I believe the 3009 improved non removable headshell 6.5 The 3009 improved with removable headshell 9.5 Then the older style 3009 SII is 12.5

My understanding as well.

 

[Blue Shadow]

I not looking for an understanding, as there is an error in either the sales sheet or all the other listings all over the web. That is my reason for looking for an actual test result. My understanding is 6.5/9.5 but the sales sheet shows 9.5/12.5 and the earlier units are 12.7/12.8, not much lower and we all thought that SME was making a move to lower mass with the Improved versions.

Which is correct.

That is the question.

 

[KentTeffeteller]

6.5/9.5 is the correct values for the Series II/S2 Improved. Verified with the CBS STR 101 test record.

 

[marcmorin]

The mass of the removable headshell (S2) version of the improved 3009 is listed all over the world as 9.5 grams. OK, but wait there is more.

The mass of the headshell, arm tube, etc. is really only half the formula to find "effective". Mass of the C/W, and its distance from the vertical pivot
is pretty much the other half to "effective". You are correct in using a known compliance, and frequency test bands to determine how much "effective" mass the suspension is seeing. The problem with "effective" mass, and going strictly by a calculated number is that it is a calc of MOI.
Once the "moment" is passed from static, the mass is now kinetic. It's the swing in kinetic force(s) of the arm mass in motion that pretty much determines the amplitude of the resonate frequency, and the band width of the frequency. ie does it only resonate at 10hz, or is there onset at 8hz climbing some at 9 hz, maxing at 10 hz and dropping rapidly at 11hz, gone at 12hz.

 

[bobins08]

The mass of the headshell, arm tube, etc. is really only half the formula to find "effective". Mass of the C/W, and its distance from the vertical pivot
is pretty much the other half to "effective". You are correct in using a known compliance, and frequency test bands to determine how much "effective" mass the suspension is seeing. The problem with "effective" mass, and going strictly by a calculated number is that it is a calc of MOI.
Once the "moment" is passed from static, the mass is now kinetic. It's the swing in kinetic force(s) of the arm mass in motion that pretty much determines the amplitude of the resonate frequency, and the band width of the frequency. ie does it only resonate at 10hz, or is there onset at 8hz climbing some at 9 hz, maxing at 10 hz and dropping rapidly at 11hz, gone at 12hz.

Marc thanks for explaining the laws of physics

I use SME's published numbers for effective mass are 6.5g fixed/ 9.5g removable. If you can select a cartridge/stylus that gets you to 10Hz res freq, you can ride out the moment of inertia swing (moving from static to kinetic) as you describe it.

Also, with damping, this will help reduce the effect you describe. Correct?

Bob

 

[gusten]

The mass of the headshell, arm tube, etc. is really only half the formula to find "effective". Mass of the C/W, and its distance from the vertical pivot
is pretty much the other half to "effective". You are correct in using a known compliance, and frequency test bands to determine how much "effective" mass the suspension is seeing. The problem with "effective" mass, and going strictly by a calculated number is that it is a calc of MOI.
Once the "moment" is passed from static, the mass is now kinetic. It's the swing in kinetic force(s) of the arm mass in motion that pretty much determines the amplitude of the resonate frequency, and the band width of the frequency. ie does it only resonate at 10hz, or is there onset at 8hz climbing some at 9 hz, maxing at 10 hz and dropping rapidly at 11hz, gone at 12hz.

The effective mass is just a mass, nothing else. The effect of each mass on an arm is transported as a mass right above the needle tip. The res is just=1/(2piSQR(CxM)) where C is the compliance and M is the total eff mass.

 

[Blue Shadow]

Marc thanks for explaining the laws of physics

I use SME's published numbers for effective mass are 6.5g fixed/ 9.5g removable. If you can select a cartridge/stylus that gets you to 10Hz res freq, you can ride out the moment of inertia swing (moving from static to kinetic) as you describe it.

Also, with damping, this will help reduce the effect you describe. Correct?

Bob

Where do you find the SME published specs? I know the 3009 is the most documented tonearm in the world so if you could point me...it could save me a lot of time looking. Thanks,

Thanks, Kent.

 

[marcmorin]

The effective mass is just a mass, nothing else. The effect of each mass on an arm is transported as a mass right above the needle tip. The res is just=1/(2piSQR(CxM)) where C is the compliance and M is the total eff mass.

I understand the formula......however, the question was about how the headshell can weight a certain amount in grams which is above the "effective mass" of the arm. The "effective mass" is a formula to find how much energy is needed to move a given mass from static to kinetic (moment of inertia) in essentially zero gravity. All of the weights of parts in front of the vertical pivots are offset by the weights behind the vertical pivots to create the effects of "zero gravity" upon the mass. My "effective mass" to the bottom of a pool while standing up to the top of my head in water is 1/6th my effective mass while standing on dry land.....my weight hasn't changed.

 

[gusten]

I understand the formula......however, the question was about how the headshell can weight a certain amount in grams which is above the "effective mass" of the arm. The "effective mass" is a formula to find how much energy is needed to move a given mass from static to kinetic (moment of inertia) in essentially zero gravity. All of the weights of parts in front of the vertical pivots are offset by the weights behind the vertical pivots to create the effects of "zero gravity" upon the mass. My "effective mass" to the bottom of a pool while standing up to the top of my head in water is 1/6th my effective mass while standing on dry land.....my weight hasn't changed.

I really have no clue what You mean. If the mass is in front of the pivot or behind the pivot doesn´t matter whatsoever, all different masses must be transferred to the needle tip using Euler´s equations. And a headshell can never weigh more than the arm´s eff mass, it´s not possible, it weighs always much less.

 

[dvdr]

It's the swing in kinetic force(s) of the arm mass in motion that pretty much determines the amplitude of the resonate frequency, and the band width of the frequency. ie does it only resonate at 10hz, or is there onset at 8hz climbing some at 9 hz, maxing at 10 hz and dropping rapidly at 11hz, gone at 12hz.

that’s exactly the problem I’m facing: how can I make sure, that the width (“Q”) of the resonance and the amplitude are as small/low as possible? And why do they differ extremely horizontally and vertically?
In my case, a SME 3009 S2 improved (I know, light effective mass!) with a heavy headshell and an appropriate counterweight plus a DENON DL103R produce a peak at 9Hz, resonance visibly starts at 6 Hz and goes up to 11 Hz. Horizontally, the amplitude at 9Hz is so big, that at times the needle jumps the groove, whereas vertical amplitude is nicely small. Tested with two copies, one new, one 20 years old. (Btw.: haven’t seen that happen in other arms like a Linn Ekos).
How comes?
Are there any differences to ”Q” and amplitude, when using lighter or heavier counterweights, that would result in different positions related to the pivot/bearings?

 

[CrSens]

Q

that’s exactly the problem I’m facing: how can I make sure, that the width (“Q”) of the resonance and the amplitude are as small/low as possible? And why do they differ extremely horizontally and vertically?
In my case, a SME 3009 S2 improved (I know, light effective mass!) with a heavy headshell and an appropriate counterweight plus a DENON DL103R produce a peak at 9Hz, resonance visibly starts at 6 Hz and goes up to 11 Hz. Horizontally, the amplitude at 9Hz is so big, that at times the needle jumps the groove, whereas vertical amplitude is nicely small. Tested with two copies, one new, one 20 years old. (Btw.: haven’t seen that happen in other arms like a Linn Ekos).
How comes?
Are there any differences to ”Q” and amplitude, when using lighter or heavier counterweights, that would result in different positions related to the pivot/bearings?

that’s exactly the problem I’m facing: how can I make sure, that the width (“Q”) of the resonance and the amplitude are as small/low as possible? And why do they differ extremely horizontally and vertically?
In my case, a SME 3009 S2 improved (I know, light effective mass!) with a heavy headshell and an appropriate counterweight plus a DENON DL103R produce a peak at 9Hz, resonance visibly starts at 6 Hz and goes up to 11 Hz. Horizontally, the amplitude at 9Hz is so big, that at times the needle jumps the groove, whereas vertical amplitude is nicely small. Tested with two copies, one new, one 20 years old. (Btw.: haven’t seen that happen in other arms like a Linn Ekos).
How comes?
Are there any differences to ”Q” and amplitude, when using lighter or heavier counterweights, that would result in different positions related to the pivot/bearings?

Q and amplitude difference on a particular tonearm will depend on stylus suspension (how well damped). Lighter counterweight away from the pivot produces more effective mass than heavier one closer to the pivot.

 

[dvdr]

Q and amplitude difference on a particular tonearm will depend on stylus suspension (how well damped).

Thanks for the answer! That's why I was so surprised with my results:
1. Is stylus suspension (damping) different horizontally and vertically?
2. Why was amplitude at the same "main" resonance frequency (=equal or closely similar effective mass of the tonearm) so different with the very same DL103R on the SME and the EKOS? The EKOS seemed to have a really good "grip" on the DL103R...

 

[CrSens]

Thanks for the answer! That's why I was so surprised with my results:
1. Is stylus suspension (damping) different horizontally and vertically?
2. Why was amplitude at the same "main" resonance frequency (=equal or closely similar effective mass of the tonearm) so different with the very same DL103R on the SME and the EKOS? The EKOS seemed to have a really good "grip" on the DL103R...

The tonearm has some damping which can affect resonance amplitude. Also the mounting on the turntable. There are many factors to consider.