@lewm, boy Lou to much coffee today?
First, as for removable head shells, you not only have the mass of the head shell but the mass of the contacts the socket and the retaining lock ring on the tonearm. A situation like an SME, Reed or Schroder is obviously much lighter. This unnecessary mass, there only for your convenience is at the end of the arm where it contributes more to the effective mass of the arm and the arms polar moment of inertia making more difficult to move. This is not my opinion Lou but obvious fact in pretty simple engineering term.
We seem to be confused on terms. A dynamic balanced arm has a counterweight that is set for balance then tracking force is added by a spring or similar mechanism. This has nothing to do with static vs neutral balance. A neutral balance arm which is the ideal has a line that goes through the center of mass of the counterweight through the vertical bearing and the center of mass of the cartridge. A neutral balance arm will not change VTA with elevation. When you position it anywhere vertically it will stay there. Examples are the Tri-Planar, the Reed 2G, the Schroder CB and some of the more expensive Origin Live arms.
Static balance or stable balance arms if you draw a line through the center of mass of the counter weight and the vertical bearing that line will go above the center of mass of the cartridge. These arms will change VTF with elevation and if you position them high and let go they will hunt up and down looking for the balance point and eventually they will stop at a "stable" balance point. Neutral balance arms simply follow the record much better. None of this is my opinion. Ed Villchur had this figured out when I was knee high to a grasshopper.
Why are you arguing about the vertical bearing being at record level? Warp wow is an obvious problem. If you don't think so take one of your test records and play a test tone with a nickel under the edge of the record. Pretty impressive! Not only can warps be a Nickle high but they are much more acute. Having vacuum clamping helps negate this problem. Raising the vertical bearing above the record surface makes warp wow worse. Again, not my opinion. The best tonearms pay homage to these design issues. The FR's may be nicely made but they are not good designs. Neither is the SAT arm for that matter. Go figure. I buy a tonearm for the best performance under all conditions. If that sacrifices convenience so be it. Heavy tonearms and stiff cartridges increase record wear and distortion during playback as the increased inertia causes the cantilever to move instead of the tonearm. I have seem oscilloscope traces showing this clearly. Some have hypothesized that this is the reason some tangential arm sound better because they are short, light and have much less inertia, following the record better, generating less distortion. Don't yell at me. Not my study and I have no idea. Makes sense though.
If you ask Mark Dohmann what is the best sub $20K turntable on the market he will immediately tell you the Sota. He is just as allergic to direct drive tables as I am. His main claim to fame is turntable isolation, isolating the cartridge from vibrations generated by anything other than the record. A suspension is essential for this purpose. I personally would never buy another turntable without an adequate suspension. But, that is me. People buy turntables for reasons other than their performance and stability.
Don't turn your turntable on and place the tonearm down on the record. Turn the volume up and have a look at your woofers or diaphragm in your case. A woofer will be not be motionless. Not sure about the diaphragm. Don't think I can see mine. Anyway, that woofer motion is environmental rumble. Some people call it room rumble but there are many causes outside of the room like the cement truck traveling down your street.
A properly suspended table will be dead silent. No environmental rumble.
I am all for spirited discussion lewm, and there have been occasions where I have been dead wrong and I do not mind at all learning that I am wrong. It is a great way to learn right. I hope we can avoid getting bitter about such trivial things.
First, as for removable head shells, you not only have the mass of the head shell but the mass of the contacts the socket and the retaining lock ring on the tonearm. A situation like an SME, Reed or Schroder is obviously much lighter. This unnecessary mass, there only for your convenience is at the end of the arm where it contributes more to the effective mass of the arm and the arms polar moment of inertia making more difficult to move. This is not my opinion Lou but obvious fact in pretty simple engineering term.
We seem to be confused on terms. A dynamic balanced arm has a counterweight that is set for balance then tracking force is added by a spring or similar mechanism. This has nothing to do with static vs neutral balance. A neutral balance arm which is the ideal has a line that goes through the center of mass of the counterweight through the vertical bearing and the center of mass of the cartridge. A neutral balance arm will not change VTA with elevation. When you position it anywhere vertically it will stay there. Examples are the Tri-Planar, the Reed 2G, the Schroder CB and some of the more expensive Origin Live arms.
Static balance or stable balance arms if you draw a line through the center of mass of the counter weight and the vertical bearing that line will go above the center of mass of the cartridge. These arms will change VTF with elevation and if you position them high and let go they will hunt up and down looking for the balance point and eventually they will stop at a "stable" balance point. Neutral balance arms simply follow the record much better. None of this is my opinion. Ed Villchur had this figured out when I was knee high to a grasshopper.
Why are you arguing about the vertical bearing being at record level? Warp wow is an obvious problem. If you don't think so take one of your test records and play a test tone with a nickel under the edge of the record. Pretty impressive! Not only can warps be a Nickle high but they are much more acute. Having vacuum clamping helps negate this problem. Raising the vertical bearing above the record surface makes warp wow worse. Again, not my opinion. The best tonearms pay homage to these design issues. The FR's may be nicely made but they are not good designs. Neither is the SAT arm for that matter. Go figure. I buy a tonearm for the best performance under all conditions. If that sacrifices convenience so be it. Heavy tonearms and stiff cartridges increase record wear and distortion during playback as the increased inertia causes the cantilever to move instead of the tonearm. I have seem oscilloscope traces showing this clearly. Some have hypothesized that this is the reason some tangential arm sound better because they are short, light and have much less inertia, following the record better, generating less distortion. Don't yell at me. Not my study and I have no idea. Makes sense though.
If you ask Mark Dohmann what is the best sub $20K turntable on the market he will immediately tell you the Sota. He is just as allergic to direct drive tables as I am. His main claim to fame is turntable isolation, isolating the cartridge from vibrations generated by anything other than the record. A suspension is essential for this purpose. I personally would never buy another turntable without an adequate suspension. But, that is me. People buy turntables for reasons other than their performance and stability.
Don't turn your turntable on and place the tonearm down on the record. Turn the volume up and have a look at your woofers or diaphragm in your case. A woofer will be not be motionless. Not sure about the diaphragm. Don't think I can see mine. Anyway, that woofer motion is environmental rumble. Some people call it room rumble but there are many causes outside of the room like the cement truck traveling down your street.
A properly suspended table will be dead silent. No environmental rumble.
I am all for spirited discussion lewm, and there have been occasions where I have been dead wrong and I do not mind at all learning that I am wrong. It is a great way to learn right. I hope we can avoid getting bitter about such trivial things.