Help with Subs and Turntable

[Xenomorph]

Hey all,
Sub(s) acting strange when I crank up the music using my turntable. Everything's fine normally but I wanted to be able to hear the music in the next room. As soon as I turned it up the sub just played a solid note. I tried unplugging one of the subs and it still does it.
Turntable hooked up to a Schiit Mani preamp, then connected to an Onkyo TX-RZ800 but it still does it when I swap out the preamp.
I have the turntable connected to CD in on the Onkyo as the receiver's phono stage is pretty terrible.
There's no noise between tracks or when I lift the needle so it's not a hum or anything from the turntable.

Here's a quick vid of the sub..kind of hard to hear but it's a steady deep note and the driver keeps vibrating like that.

https://www.youtube.com/watch?v=Rv31...ature=youtu.be

[Xenomorph]

Problem solved please delete post.
Believe it or not the dust cover on the turntable being left open was causing a weird sort of feedback. Closing it fixed the problem. :O