[sts9fan]

When I turn up the stereo to what I would call "medium high" the sub starts makin a mechanical "thuawacking" sound.  I do not think it should be too loud as I think I read Danny say it has pretty high output.  It's the servo 12 in the sealed box offered a bit ago as a package.
Thanks
kris

[Danny Richie]

Yeah it shouldn't be doing that. Is the driver reaching its X-max and bottoming out or is it something else?

[sts9fan]

How would I figure that out?  It does look like it is moving a ton.  What does bottoming out sound like? 

[Danny Richie]

I don't know for sure as I have never bottomed one out.

That package deal came with the 300 watt amp so chances are less that you are overdriving it but it could be the case.

I'd back off on the volume setting a little bit.

[sts9fan]

I will but does not seem like it should be too loud.  I will take a measurment of when it happens. 

[cujobob]

Is the driver wired correctly?  I had an OB servo sub that went nutso because of miswiring.  Just a thought, though not likely.

[zybar]

Is the driver wired correctly?  I had an OB servo sub that went nutso because of miswiring.  Just a thought, though not likely.

Same here.

Once wired correctly, no more thumping or whacking.

George

[sts9fan]

Pretty sure it's cool.  Mainly cuz it just started to happen.

[rythmik]

Pretty sure it's cool.  Mainly cuz it just started to happen.

check if there is any air leak. Air leak can cause the air spring to be insufficient.  If the driver has been damaged, it generates a noise even when you just tape on the dust cover.

[sts9fan]

Will do.  Do you just feel for them or listen?