Exhaust Quiet Baffles

Anyone out there have any experience with quiet baffles for slip-ons? I recently purchased and installed cocktail shaker slip-ons for my 82 KZ550C LTD that I am working on. They come with a baffle installed but the high pitch ping is way too high. I am looking to quiet them down as much as possible. The preinstalled baffles are 2"x7-1/4" long. Any help would be greatly appreciated.

How does the fiberglass packing look? If it is deteriorated or missing, replacing it might solve the problem.

If they were made by a major manufacturer, an optional baffle may be available.

A third option wold be to modify the present baffles or fabricate entirely new ones that suit your goals.