Subwoofer rumble issue

paulgardner OP3 posts11-17-2019 2:11pmGeorge- I’ll give that a try when I get home tomorrow. Thank you

Yep air-born feedback.
I bet nearly 100% it’s your problem.

1: Remember system all on including sub (not in standby auto switching mode).
2: Stylus on a record but not spinning,
3: Turn volume up to your normal loud position.
4: One hand on the volume control, with the other hand solidly tap the turntable plinth with end of your finger .

And watch your "finger donk" on the TT plinth turn into an ever increasing earthquake with airborn-feedback and continue to get louder and louder as it starts to run away and if not stopped will take out your amp and speakers.

Cheers George

The sub is driving the room. Some room are incredibly microphonic. Isolate the sub from the rest of the system by putting it on short stiff springs. You know, like Super Stiff Springs. Trademark. Problem solved! 🤗

Thanks for all the reply’s and ideas, awesome! I’m running a Clear Audio Concept table and the sub is a REL T9i. They’re both very good products so the lack of quality materials in the turntable build is likely not the issue. I will do the stylus down on a still record/finger tap on platter test later today and report back on the weather conditions - earthquake or other! I’m not sure how I feel about a subsonic filter. Maybe as a last resort but moving the table to another room is not really an option - I live in a 2 bedroom condo loft with 20 foot ceilings so it’s essentially one big open space with 8 foot half walls for bedrooms and a bathroom and furnace/washroom being the only closed off rooms. I will report back on my findings! 

I had the same problem after moving my table from a sand-filled platform to a new wife friendly cabinet. 

A Ginko cloud platform solved it for me.

I should add all (rpt all) components including front end electronics should be isolated. Not only because of subwoofer mechanical feedback but also structure borne vibration. It’s a vicious cycle.🔄