Tonearm / Catridge matching?


I have a potentially stupid question about tonearm in general, and linear tracking arm in particular. I am using the Rockport 6000 tonearm, and in his reviews, Michael Fremer had repeatedly stated that the 6000 sounded excellent, but a little weak in the bass. He stated that “ The 6000’s relatively low vertical effective mass put its resonance frequency above the ideal 8-12 Hz region with moving coil cartridges of average weight and typically low compliance, causing the bass to begin rolling off prematurely”. He also stated that Rockport had solved this problem in the 7000, and the arm on the Sirius III, by using heavier armtubes.
Now, if the objective is to make the armtube heavier (so it has a higher effective mass), and assuming the armtube is already rigid enough on the 6000, can I simply add a little lead spacer between the cartridge and the headshell to increase the effective mass and achieve similar result. If this method is workable here, does it also apply to fix pivot arms. Am I missing something here?

Thanks in advance

Michael
thekong

Showing 2 responses by pittsflyer

While we have some expertise on the line, I'm trying to go the opposite direction. I have a Grado Reference Sonata on a Graham Robin with a resonant frequency of 8.5Hz. Two questions come up: Will reducing the tonearm mass help reduce the substantial infrasonic signal, and if so, does anyone manufacture a very lightweight headshell?
Thanks for the replies. I'd prefer not to replace either the arm or the cartridge, but the inescapable fact is, the combination produces a ridiculous amount of woofer pumping. The resulting IM distortion is so unpleasant that I inserted a couple of capacitors after the turntable to roll off the lowest frequencies. The problem, however, is a mechanical one, and I hope to solve it as such.