12" arms - VTA advantage?

We have all read the discussions about different distortion levels and tracking error between 9" and 12" arms. I have just spent some time readjusting the VTA on my SME V. As adjustment is not "on-the-fly" or easy like on some other arms, I have decided to set it for the thickness of the majority of the LPs I enjoy listening to most, thinner, classical music, in my case. For the thicker 180g reissues, the VTA ends up being a bit lower in the back than is ideal.

Would a 12" arm not reduce this VTA height difference more that a 9" arm? Leaving aside the disadvantages of the added mass of longer arms for the moment, is this not another advantage of the geometry of a longer arm? Why is this not discussed as much as the distortion/tracking issue.
It's not discussed because it will be in exactly the same place. The only advantage of a longer arm is, if you play a thicker, or thinner, record than your VTA/SRA is set for, the angle at which VTA is off is slightly decreased. Likewise, when tracking warped records, the angle that the SRA is off will be marginally less with a longer arm. The Dynavector arms really have a pronounced change in SRA, as well as having very different horizontal and vertical primary resonances, due to the extremely short arm.
Yes, Viridian. It is clear that the arm doesn't move up or down at the base. But because of the added length, the VTA/SRA should change less with different LP thicknesses. Is this less change great enough to be audible? I guess I should have written that the 9"/12" arm discussions usually address differences in the horizontal plane and not in the vertical plane.

I wonder if anyone has made a study of the SRA differences in percentage terms between different arm lengths like they have done with tracking distortions.
For a 12" arm a 1 degree change in SRA would need a raising/lowering of the arm by about 0.21". For a 9" arm this number is about 0.16"
Sorry, if this is not an answer to your post. I have not tried the mat either, so don't know how it sound. Here's the link and hope it help.


Thanks for the link. I have an SME table and prefer to use the SME damping material on the platter under the LP as I find their "record/platter interface" solution very effective.