Congratulations! That's exciting to read. I got a vicarious thrill. It's possible that you might hear the effects of other tweaks better now.

Doing everything you can to minimize resonance in your speakers is one of the best tweaks around. Try stacking some books on top of the cabinets and see if that does anything.

That sand, which frustrated you, has wonderful acoustic properties. Have fun. You deserve it.

Cheers,

That is a killer tale!

Your endorsement means more to me than a thousand full page advertisements!

Kudos.