So Weird- No Stylus Contact Woofer Pumping with Hana ML and Elac PPA-2

A few questions;

1. Isn’t woofer pumping caused by infrasonic frequencies (below 20hz)? A John Atkinson quote from 2009 Stereophile seems to support this, though he was referring to record warps in that quote;

https://www.stereophile.com/content/bass-cone-flap-1

2. The PPA-2 has a rumble filter and I believe that I saw it turned on when the woofer pumping is occurring - doesn’t a rumble filter filter out these frequencies precisely for this reason - to prevent large woofer excursions? If so, it would seem the rumble filter is not working on this phono stage - you may want to look into a warranty repair if we can assume the woofer pumping is being caused by infrasonic frequency.

3. Not sure how static would cause the cartridge to output signal in the infrasonic range. Even so, the Funk Firm mat claims to be static free, yet with just that mat on the platter still exposed this issue; so if not static, then what?

OP - Thanks for your indulgence. Think I may be developing ADD in my old age (turned 70 in Jan). Totally missed your original post.

As for the problem, damn that's weird! Got to have something to do with static elec/low humidity.

Thanks again. 

Attention Deficit Disorder? You’re probably just noticing it because you weren’t paying attention before.

@ejb14

1. Isn’t woofer pumping caused by infrasonic frequencies (below 20hz)?

Yes it is

2. The PPA-2 has a rumble filter and I believe that I saw it turned on when the woofer pumping is occurring - doesn’t a rumble filter filter out these frequencies precisely for this reason - to prevent large woofer excursions?

The weird thing is that the hi pass filter works, I have some real nasty LP’s that rumble and the filter knocks it out. So your guess is as good as mine. Also the pumping was worse with the filter off- real audible bottoming out stuff.

3. Not sure how static would cause the cartridge to output signal in the infrasonic range. Even so, the Funk Firm mat claims to be static free, yet with just that mat on the platter still exposed this issue; so if not static, then what?

I’m still all in with team static, until a more likely explanation is revealed or Peter Madnick see’s this and can explain it.

70% of people are stupid. Fortunately, I'm in the other 40%.