Woofers pumping

On two occasions I have noticed the woofers of one speaker moving 1/2 inch excursions. Both times the SPL was peaks of 93 dB.

System is CD player, preamp, amps.

This has happened with two different amplifiers.

I spoke with the tech at B&W and he didn't have an answer.

tomcarr07-17-2023 8:45pm

tomcarr OP Details Discussions Posts This discussion Message User 1,818 posts 07-18-2023 at 06:04pm Copy Comment URL Report Comment Edit Delete @erik_squires The woofer is just a slave... Doh! I should have known that. Good point. Even more embarrassing, I've been involved with this hobby since 1975...🙄
tomcarr OP Details Discussions Posts This discussion Message User 1,818 posts 07-18-2023 at 06:07pm Copy Comment URL Report Comment Edit Delete @mlsstl Good Point! Will listen to the two songs that it happened on again...
tomcarr OP Details Discussions Posts This discussion Message User 1,818 posts 11-07-2025 at 07:06pm Copy Comment URL Report Comment Edit Delete Finally got around to swapping L and R at the preamp outputs. Lo and behold the pumping motion also swapped from the R speaker to the L speaker. I always listen with grill covers off. If I left them on I would never have noticed. On the extremely rare occasion when it happens, I just turn the volume down.
bache Details Discussions Posts This discussion Message User 581 posts 11-07-2025 at 09:10pm Copy Comment URL Report Comment Edit Delete Check speakers wire connectors ,
atmasphere Details Discussions Posts This discussion Message User 12,422 posts 11-07-2025 at 10:27pm Copy Comment URL Report Comment Edit Delete @tomcarr Its very obvious the problem is either the preamp or your source.