Phasemation Cartridge Compliance or Alignment Issue?

"Distortion on only the outer record groves and not the inner groves is normally an alignment issue or an anti-skating issue."  First, the problem is woofer pumping, which can be a cause of distortion due to a controversial form of Doppler distortion, but not other kinds of distortion. Second, even when an overhung pivoted tonearm is perfectly aligned, there are only two null points on the LP surface. Everywhere else there is tracking angle error, but it is worst in the space between the innermost null point and the runout grooves. Misalignment is likely to worsen the alignment in that region more so than at the outer grooves. So I don't see why misalignment would necessarily make for outer groove distortion while inner grooves are relatively unaffected (but again, I am not sure the OP is hearing much distortion, just woofer pumping). Anti-skate is always a crap shoot, but by what mechanism does it cause woofer pumping? Anyway, we agree that rumble filters are to be avoided when possible, but in this case if you take a pragmatic approach, perhaps the rumble filter will alleviate the problem.

Thanks for the ideas everyone.

I am experiencing a few different types of distortion. In the outer grooves of some records, I've noticed some midrange tones struggling to hold their pitch. For example a guitar string pluck wavering back and forth.

Another form of distortion I've come across is a strange scratching high frequency sound almost like an aggressive tape hiss that occurs rhythmically with each platter rotation. This behavior occurred several times on one record I was listening to in more central grooves as well as the edge of the record. 

I've probably listened to a dozen records over the last few days - each seems to have different sonic behavior and cause differing amounts of woofer pumping. Some records don't cause my woofers to pump at all.

@bill_k  interestingly enough, a few warped records that listened to last night exhibited the least amount of woofer pumping. They actually played better on the side with the edges cupped upwards. I have a record weight that flattens them out on the other side.

@jsalerno277 I want to go through your list here:

1. Warped Records - as stated above, some of my warped records actually exhibited the least amount of woofer pumping. The cupped side exhibited different behavior from the flattened size. I'm confident that I nailed the alignment with my recent reinstallation.
2. Turntable Rumble - I have a 3 year old MoFi Ultradeck. I recently cleaned and relubricated my inverted bearing. I would think there has been no change with my setup here.
3. Turntable Isolation - I have my turntable between my speakers which are about 7 ft apart. The turntable is sitting on a custom steel and wood shelf that I designed. Heavy butcher block shelves are supported on black and blue heavy duty equipment vibration pads you might install under an industrial fan or refrigerator. I don't have any issues with footfall due to this shelf. I don't really have the ability to move my turntable elsewhere. I know that I have a pretty serious hum somewhere in my system that is audible if I don't ground the turntable but absolutely fine otherwise. I have a combined HT and 2 channel setup with a HT bypass integrated amp, processor, TV with eARC, and sub. Sometimes if my cables shift around, I need to position my right channel phono cable just right for the right channel to play. There are plenty of places I could be getting feedback from.
4. Speaker to Stylus Feedback Loop - I never had the distortion or woofer pumping issues with my previous factory fitted MoFi master tracker cartridge. Perhaps the phasemation is more sensitive to feedback?
5. Tonearm Mass/Compliance Mismatch - The online calculator I used has my system resonance at 6.4hz assuming the 25.14g tonearm mass. I have reached out to MoFi to confirm this assumption. I think this is likely what I'm dealing with. Unfortunately I think I will need to swap out the Phasemation cartridge. I don't love the idea of the rumble filter as I doubt it will solve the high frequency distortion I was hearing.

@lewm I hate the antiskate mechanism on my turntable, its inaccurate and unverifiable. You set an O-ring and counter weight on various notches that are supposed to pair with different cartridge weights. I have tried to play records with the setting at each end of the possible spectrum without any noticeable change in behavior.

I'm to the point of searching for a low compliance cart that will work with my current stage phono preamp. I'd rather not abandon the Sutherland if I don't have to. I'm thinking the Ultragold MC could be a good match. It has a proven compliance match and its 12 ohm resistance should function with the Sutherland. The only specification I'm missing is the inductance of the cartridge. Another option I was considering is the Miyajima Shilabe but this is a much more expensive option. I don't really want to go down this rabbit hole again and find I still have mismatch issues.

Instead of wasting all the time and money on cartridges why not sell that table for one that has an arm that is more compatible with most cartridges? Just my opinion!

Regarding the possibility of the problem being feedback from the speakers to stylus, I don't believe that's what you're experiencing. When such a feedback loop is encountered it's experienced as a growl that increases in intensity until you turn the volume down.