Weird sound please help

I have a weird sound that happens while listening to records. the sound is a loud 'wump'. That is the best description I can give you for the sound itself. The equipment I am using is Manley neo classic 250s, Manley Steelhead, Genesis G5.3 speakers, a Brinkman Bardo turntable with a Origin Live Conqueror arm and I am currently using the ZYX 4d cartridge. I also use the steelhead as a preamp for my DAC if have never heard the 'wump' while listening to the DAC...

I have experienced the sound with my last speakers so I don't think it has anything to do with the speakers. I have a feeling it is the Steelhead but not sure why or what I should do.

the sound occurs most if I turn up the volume or if there is a loud musical passage. @ higher gain it happens more frequently. but it still happens at gain set at i am testing gain at 50 the lowest gain setting on the Steelhead.

If I turn up the volume using the Manley Remora (remote control) I will surely get the sound to take place within 30 seconds though not always...

What the hell is it and how do I correct it?

thanks for your imput; I appreciate it.

Sonic feedback from floor to cartridge.
You either have to isolate the TT better from the vibrations, or keep it turned down. It can kill your stuff.
Sounds like a feed back problem. Do you have a subsonic filter?
Just relocating your tt relative to your other gear can stop it. Or get yourself a linn. The old Aristons are probably the most imune tts ever made.
Sounds like a feedback issue.. I have my equipment on a Solidsteel stand the turntable is on an HRS stand then on the Solidsteel shelf. what else can i do to isolate this better?

thanks, JB
You simply need to break the acoustic cycle being set up by your cartridge and speakers. They happen to be located just right in relation to the walls and ceiling of the room.
Nice rig. If its feedback, consider yourself lucky b/c it can be easily cured. Try a wall shelf, sand box, relocation to a different location, or perhaps a subsonic filter-KAB is supposed o be excellent. If its your electronics, try to get a working phono stage in its place to see if you still get a noise. But I bet its feedback.