Why are my woofers pumping?

@o_holter : problem is that you just noted it and could be many thing. Even that speakers can't reproduce the frequency the woofer movements are affecting the quality level performance of what you are listening.

Even a mistmatch impedances between phono stage and line stage could be ( for whatever reason. ) the source. The electronic very low bass oscilations are more frequently that what we can imagine.

You have to make several tests about because exist no rules to make a sure diagnosis about.

R.

o_holter

Thanks Cleeds, but I don't agree. Please prove the case. Why does the arm kill the cartridge?

The SME V is a terrific arm, but your woofer pumping problem simply suggests you've mounted the wrong phono cartridge to it. There's no reason to suffer such a problem, imo, and using a subsonic filter is treating the symptom rather than the disease.

Question for @o_holter : Did you buy this cartridge used?
If so, all bets are off. You can't be exactly sure of what you have.

@o_holter 

Raul's suggestion that the cantilever suspension is failing could be an explanation, but the problem I have with that is the cartridge must be pretty new so this seems really unlikely.

I looked at the specs of the ARC used in the review; it cuts off at 10Hz. Your preamp, if still the Io, is only specced to 20Hz (at which point its within 0.25db, suggesting that it can go down considerably further). So its an unknown as to whether that's an influence. Your amps are full power to 1 Hz. I use similar amps in my system at home, but I don't get the woofer pumping, although that was a problem when using the SME5 and has not come back while using the Triplanar (which I see was used in the article you linked, so this problem may not have shown up).

A filter will introduce phase shift, and in a full range system such as yours, will be audible as less bass impact. So its probably best to solve this with elegance rather than brute force.

@o_holter Does this happen when the woofer and other equipment is not in the sun?