Help deciding which TT

Thank you everyone for your ideas.

It's an odd thing.

As I mentioned, just having the needle dropped on a stationary record and turning up the volume level is enough to kick in the rumble. The room is perfectly silent while doing these test.

What's interesting is that I can actually dial the volume up louder when the patter is spinning and music is playing.

If I turn up the volume with the tonearm in it's resting place, I get zero rumble/woofer flapping. I use a zero dust to clean my stylus. If I lower the stylus onto the zero dust, and then increase the volume I also get no rumble/woofer flapping.

The subwoofer is connected to my Anthem MRX HT receiver via LFE connector. No issues with digital sources of course. My phono preamp is a Rega Mini Fono A2D.

I created a custom grounding wire awhile back that connects the bearing well on the Rega to the Mini Fono A2D. I found that it eliminated some HUM I get in the Winter when the air is very dry. Connecting and disconnecting the wire makes zero difference.

If the issue is a grounding problem, it seems like the source is the tonearm itself. The RP1 doesn't have a separate ground wire for the arm. It's supposedly grounded through the RCA connector.

"It is acoustic feedback from the sub into the turntable body...bearing...platter...stylus. Put a slab of granite under the TT on the wall shelf."

I have a 30lb two inch thick slab of Maple between the wall shelf and the Rega. The rega sits on top of four Herbies tenderfeet instead of it's normal three stock feet.

The Martin Logan Grotto i subwoofer is the only thing connected to the LFE output on the receiver. The phono preamp is connected to the receivers analog (AUX) input. The only time I've ever used the USB is to connect the preamp to a computer for recording.

I don't think the Rega Mini Fono has the ability to lower the gain on the analog connections. I think the gain control only works with the usb port.

"Your sub is to loud, turn the volume down."

Your probably on to something there. I have it set where I like it for digital sources. I can decrease the volume on the AUX input so I'm going to play with that.

The wall shelf I purchase is not the Rega brand one with the cups that line up with the feet. That shelf wouldn't work for me due to how it's built with the bracing. With the shelf I have now, I was able to slide my buffet directly under the table. I did try a lightweight bamboo cutting board before the maple slab. The maple slab seemed to reduce the flapping better.

I'm at the point where I feel like I have three options.

1) Purchase a new TT (one of the tables I mentioned in the original post). I probably going to do that anyway. I purchased the RP1 to see if Vinyl was something I wanted to get into, and now I have over 500 LPs. I'm here to stay.

2) Pickup a Phono preamp w/subsonic filter, or purchase a KAB RF1. The RF1 just seems expensive at $179 when I can pickup a Pro-Ject Phono Box DS for a little more money. I'd Consider the Cabridge Audio 651P as well, but I don't know the specs of it's subsonic filter (where it starts to filter and how steep of a slope).

3) Forget using the subwoofer with Vinyl. It might come down to this in the end.

A quick update. I had the stylus sitting on a stationary record, and turned the volume up to the point where the subwoofer started to slightly pump and the sound (low level rumble) was just audible. I gently put my hands under each side and exerted a slight lift upwards. The rumble went away. I didn't have the TT completely lifted off the maple shelf, but I was in essence making the TT lighter.

Now all I need to do is create an forced air cushion that would suspend a TT in the air. Or a device that modifies the higgs field around the TT to lower it's mass.

Seems a better built TT might be an easier option? :)

"As I said above, bicycle inner tube. But you seem to prefer anti-gravity guns and new turntables."

I'm willing to give an inner tube a shot. I did try some packing air pockets under each of the three feet, and it really didn't seem to make much difference. They are the things that they use in shipping instead of packing peanuts.

Would a 12" diameter work? The RP1 has a footprint of 17.5x15. I can also get a 14" tube as well.