I have my racks fabricated in my friend's offroad racing ship. Like yours they are 1" steel tube. I cut 4" heavy wood slats that I can place under each set of feet on each component so there is air under the equipment except for these stripes.
Picture in my biography.
I can't say it improves sound since I have always had it. My speakers have drivers all the way down to the floor. But I am very happy with it. I'm gettting a 3 chassis custom amp built so I'm going to have to design a 3 shelf version.
Jerry