Hi there.
Hope I'm posting this in the correct area (if not, please feel free to move it)
My Usher speakers have a lower sealed cavity that can be filled to add weight and potentially improve the bass.
Has anyone had any experience with this - and, do you have any suggestions on what to fill it with?
Thanks........
I had the pleasure of spending some time with Paul Chen from Usher at RMAF 2006.

I told Paul that I had 25 pounds of led shot, in bags, in each of my CP-6391's.
In Paul’s opinion that is not enough. He recommends filling the compartments to capacity with
LOOSE led shot for optimum performance. He stressed the point that bagged shot is considerably less effective then loose shot.
The 6391’s should hold about 50 pounds of loose shot.
He recommends tilting the speaker forward when loading the shot.
This will allow you to get more shot into the compartment.
I considered using micro bearings but the delta in cost is significant so I went with led.
Obviously the best thing to do is experiment to see what sounds best to you.
Best of luck,
Jeff