I have also been experiencing this issue for a few months. Removing and reinstalling applications does not resolve the issue. I also receive this behavior in TV (antenna) audio as my TV passes it through to the soundbar.
I have powered down for >5 minutes and powered back up. I have reseated and replaced my TOSLINK cable from the TV, I have reseated and replaced my HDMI cable from the TV. The only workaround I have seen is disabling bass on the soundbar entirely, which was the point of purchasing the product to begin with. The rattle seems to be more of an issue with defective physical woofers than software as the issue has gotten progressively worse. I'd also note the remote lag is significantly more noticable than the Roku 3 HD I bought this to replace for both my poor TV audio and my older Roku hardware.
Software 10.0.0 build 4209-95
Uptime 6 hours 15 minutes