Had a very similar sound and mine turned out to be the sway bar.
It had gotten torqued in the bushings and the corner would catch on the rib of the control arm. When I loosened the sway bar bushings it srang back with a loud twang.
If it has been doing it for a while it will have some scuffs on the corner of the sway bar and control arm.
please oh please post a picture of this, I think I have that problem but can't picture what you are describing. New Bilsteins going in this weekend as PM and thinking it may help, but now I'm thinking about sway-bar bushings too.
TIA,