Big problem with sub Klipsch R-112

Bought two years ago. The problem started six months after and still here while deep bass. Sub has been sent to sav but was returned with the same problem.
Is it normal ?
Denon x2600h
Volume 65
Cross over 80hz
Lpf to lfe 120hz
LFE only (not LFE+main)
I've tried a lot of settings whitout results...

[@kovacsmihalymihajlovics6510]

the cables (2) going to the membran ar somehow got free. Normally these are sticking to the back of the speaker and just a little piece of these are free to let the speaker moving. It seems in your sub these two cables arent with the membran anymore, they are fully free and they are touching the membran every time it moves big distances when low freqs comes. U can send it back and explain them what the problem really is.

[@B4evrtru-26]

that appears to be something loose inside the enclosure

[@ryanverwey2589]

had this with my r115, turned out to be a lose cable from the amp

[@PS4PROGAMER5456]

Somthing in the port

[@baconsausage4730]

So long story short your sub is fine yes but it's hitting the inside of the magnet because it was not center correctly

[@greyshadow7786]

Tinsel lead slap is what its called

[@SkittlesScott]

turn the gain down

[@luistexon5752]

No, no it normal :(