Confused about compliance matching with airbearing


Chrome doesn't let me post more than a paragraph, so let's try again.

I am ordering a Soundsmith Voice. I currently use a 20cu Grado with no issues, 10hz vertical resonance, on an MG1 airbearing.

Petere advised against the 28cu model which confuses me because Trans-Fi owners are use 32cu carts with what seems to be much more lateral mass.

Should the horizontal effective mass be high in order to use high compliance?

"Keeping the wand short reduces resonances within the arm which typically colours the music. It is probably one of the major influences contributing to the overall sound of a tonearm. Manufacturers of conventional pivoted arms go to great lengths to try to eliminate resonances. They have a hard job!
Together with a lightweight slider, Terminator has the lowest lateral inertia of ANY airbearing tonearm on the market weighing in at just over 80g including the saddle, counterweight & cartridge, allowing safe tracking of the fussiest high compliant cartridge."
doctorcilantro
Its high compliance=low mass and low compliance =high mass in all the arms I have used. The higher the compliance the lower the mass of the arm should be, I don't see why air bearing arms would be different but I have not used them.
Airbearings have a much higher lateral mass than fixed pivot. Seems Trans-Fi is about 80g (stock), MG1 appears to be about 65g with Grado. More worried about stressing the ruby cantilever with a really high comp. cart.
Lots of info on an earlier string around this subject. Heavier cartridges and heavier arms will result in more stress however my polling of people who actually own linear arms (air bearing arms) does indicate that the better quality arms do not show a significant track record on causing damage. I currently use a zyx universe cartridge with Silver base, Airy 3 with silver base, and have used a VDH frog with no problems. My Maplenoll apollo has a very short arm that is ceramic and the air spindle is a light weight material. I did upgrade my ariadne reference and signature with a carbon fiber wand and spindle with fantasitic results and those modifications dramatically lowered the mass. I have used my universe cartridge many hours with no deflections or damage to date. That being said, lots of feedback from some very passionate and knowledgeable people who prefer pivots strongly advised about the potential damage you are refering to. In addition, there is a basic mechanical fact in that the stylus does carry the horizontal vector force resulting from the lateral movement of the arm.
However, 6 years of linear arm use and several thousands of hours (i listen to a lot of music)of use has never resulted in a problem.
I am not at all clear on the significance of lateral mass. There are posts on the internet to indicate that ADDING lateral effective mass, e.g., by fixing weights to either side of the pivot (in a pivoted tonearm, of course) has a beneficial effect. Persons who comment on this mod do not mention a differential effect for low vs high compliance cartridges. Indeed, there are several classic Japanese tonearms that incorporate the same idea, e.g., SAEC. The Dynavector tonearms (old and new) are designed deliberately to have a high mass in the lateral plane, and this is touted in their brochure as a benefit of their design without regard to cartridge compliance. On the other hand Fremer often comments that a disadvantage of most linear tracking arms is their inherently very high mass in the lateral plane. The equation for resonant frequency does not contain a term for lateral effective mass, only vertical (if memory serves; I did not check this), so I don't see that lateral mass will affect resonance. Yet, it is not hard to see why a high lateral effective mass might place undo stress on the cantilever of a high compliance cartridge as compared to a low compliance one, just as high bearing friction in the lateral plane could also do. As far as I am concerned this issue is very muddy.
With cartridges of high 30-50 compliance it has been easy to see cantilever deflection in action, to hear the associated distortions, and to compensate by releveling the manifold to "center" the cantilever. I can't measure level accurately enough to know precisely where the optimal position is relative to true level, but I think it is with the manifold tilted slightly down toward the spindle to invoke gravity as compensation for lateral inertia. Then one should readjust azimuth...

With Trans-Fi a lightened sled improves the sound of a high-compliance cartridge, but this may also owe to superior damping properties of the low-mass carbon/foam construction of my lightened sled. I need to experiment with weighting this sled in order to separate these variables.

At the opposite extreme, Vic of Trans-Fi mentioned that with a low-compliance Denon 103 cartridge he tried weighting the sled with up to 100gm additional, and heard little difference.

Finally there is the impact on performance and wear of bearing friction-- which is presumably lower on an air bearing than on a pivot arm. This is a small force in either case, yet one more variable to add to the murk.

I can't comment on stylus wear, since of a half-dozen high-compliance cartridges in my possession none has exceeded several hundred hours.