those cavities on the A7's

[main_street964]

GM ...

"though I recommend something more massive such as kitty litter".

i went to purchase kitty litter only to discover that there are dozens of different types from "soft timber" not very dense to "bentonite". the bentonite would require over 20 kgs per horn cavity.

is this the kitty litter that you were talking about GM?

and do you need to fill to the very top of the cavity?

thanking you for your help

[GM]

Hmm, people and their pets....... when I was buying it was a nice smelling bag of Oil-Dri, so maybe the latter will be the cheapest nowadays.

Yes, you fill it all the way, tapping the cab sides to settle it as you go and yes, the cabs will gain a lot of weight, just not as much as with sand, Portland cement, crushed rock, etc.. Truth be told, I actually filled cavities with used Oil-Dri when I had enough and only used fresh when necessary, so don't know how much is required.

Also, to maximize the effectiveness of this tweak you need to stiffen the top and bottom of the horn till they ring at a frequency above 500 Hz where they can't be audibly energized. Scrap pieces of 1x3 or wider boards or similar widths of 3/4" plywood strips glued on edge for the bottom and bonding a 3/4" thick plate of void free plywood such as 11-13 ply Baltic Birch or Appleply to the top of the cab suffices.

GM