Subwoofer rumble issue


I’m having a hard time solving a problem that seems to come and go. My subwoofer will rumble uncontrollably when playing records at a higher volume. If I turn the volume down sharply it goes away but when I creep the volume back up it comes back. I’ve tried isolating my turntable as much as possible with diy books, isolation feet, etc. (I don’t want to buy an expensive isolation platform unless that really is the issue.) Any thoughts on what I can do to fix this? Thx!
paulgardner

Showing 18 responses by geoffkait

Surely you must believe most other people are as backward and incapable of real progress as you. I’m considering putting you on the payroll nevertheless in view of your excellent job of getting the word out. 
The airborne feedback is not the issue, it’s the structureborne feedback. That’s what the fuss over isolation is all about. Wake up and smell the coffee! ☕️
He already told us what brand and model the subwoofer is, a REL T9i.

wolf_garcia
Note that Dylan does NOT say "best of luck to you" at the end of his records.

>>>>Dylan said he does. He said so in an interview in San Francisco. He even has a song about it.

https://youtu.be/uWaKrLLtQPg
Georgie Porgie and misogyny, are you dudes high or just forget to take your smart pills? 💊 💊
You lost me. What do you mean, all hell broke loose? Is that a variable phase knob?
It was in the correct phase when - before you switched the cables or after? When your sub is in correct phase is the turntable problem worse, better or the same as when the sub is out of phase? 
Wouldn’t that mean the subwoofer is in correct phase. If it’s out of phase (polarity) the bass would be reduced, right?
And what’s causing the problem with the table? The subwoofer. The REL is driving the room. It’s the structureborne vibration, seismic plus Rel. The resonant frequencies Fr of the cartridge and tonearm are circa 8-12 Hz, the platter can be even higher. Some rooms are incredibly microphonic, especially the upper floors of buildings. Some racks/stands amplify the vibration. The REL weighs only 42 lb so my cryo’d Baby Prometheans would be sufficient to properly isolate the REL. $48 free shipping, cannot beat with stick!
Paul, as Bob Dylan says at the end of his records, best of luck to you.
Hint: don’t tap the plinth whilst music is playing. Hint #2: that’s exactly what isolation is - a subsonic filter! Problem solved! 🤗
My bad! 🤗. P.T. Barnum says if something is not promoted something terrible happens. Nothing. 
I have Springs for Subwoofers on sale on Audiogon as we speak. Wink wink 😉 By the way, Even if you didn’t have an audible problem with the sub’s woofer the springs improve the sub’s performance per se by allowing it to operate with less distortion. It’s a win-win! 🤗

All the problems lying dormant in the system spring to life, as it were, when the volume is turned up. - old audiophile axiom
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.🔄
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! 🤗