Changing phase makes subwoofer rattle - why?

[bunshi]

Extensively searched google, this forum and htguide, couldn't figure this out.

I bought an old sony subwoofer and replaced the driver it with a peerless sls 830667 8".

Sub rattles when set to "normal" phase.

It's certainly not xmax, because I turn the volume to about as low as it can go, so I can only hear it when I put my ear right next to the cone, and when phase is normal, it rattles, when I switch phase, not only does it not rattle at this low volume, but it doesn't rattle when I crank it to about 30 watts playing a solid 20 hz sound. ( I know what xmax sounds like because beyone 30 watts, you start hitting that xmax).

I've read that the phase button on some cheap sub amps just controls the polarity of the current. It's weird, because the connectors for the woofer terminals are sized to fit the wires, unless the original sub was wacky and reversed.

I'm not really worried about it, because obviously I'm using the "non-rattle setting".

Just curious.

[sregor]

Piques my curiosity too. 1 - Try reversing the speaker lead connections at the speaker and see if it still does it in the same switch positions. 2 - look at the woofer and see if perhaps there is a small amount of DC causing it to move in or out when the switch is moved. 3 - if you have access to a scope - see if there is anything funny going on with the wave form.

[dannyjmf]

Are u certain after u have replaced the Subwoofer the driver is screwed on firmly onto the enclosure? Also check for Large panels on the enclosure to amke sure they are properly braced and also considering add some damping material.

I hope this will help you. Good luck