sub is randomly thumping?

[MrSo0h0o]

hey guys i was wondering if anyone had an idea whats going on. lately my sub has been making random single thump noises. obviously i can only tell its going on when the volume is low. i made sure the RCA's werent touching any metal, and i moved my amp around a little to see if it made a difference but still the same. could this be something to do with my voice coils?

here is basic specs on my setup:
sub- RF Punch HE2 10" old school.. 300w rms.. dont remember the VC config
amp- Xtant A3001 300w rms @ 2ohm, 150w rms @ 4ohm

what is some basic troubleshooting i can do?

TIA

[Black95Cam]

try grounding your RCAs termal on the HU itself and see if that helps.

[ZerocooL]

that might help, i know that sometimes disconnecting the battery blows the ground on some HU's the way to fix that is actually like Black95Cam said, grounding the RCA outputs to the chassis of the HU.