Since a long time I was confident that eliminating feedback from loudspeakers, my military box was terrible. Tried out crazy ideas like the Ikea lack, which is even worst. Played around with lifting, isolations, but no improvement. The last push was from Zsolt Bodnár (72 audio) to be not lazy and build a stand. (well was lazy to just borrow sizes from him, thx ) Here are some pics and guide for other lazy DIY-ers, who just need the last drop to build such. The result is very good for turntables or tube amps where microphony could be a problem.

2pcs 250mm, cut on both side in 45degree on the 40mm sides

2pcs 500mm, cut on both side in 45degree on the 40mm sides

2pcs 430mm, cut on one side to 45 degree one the 20mm side

1pcs 500mm cut on both side to 45 degree on the 20mm side

On 500mmx 445mm ~40mm hard wood table

4pcs ~6mm damping pod

Result: