Equipment rack with hollow tubes.

lostbears...Oh ok so it is for vibration more so for TTs... Thanks

@elizabeth  Would it be worth adding the sand even though i dont use a TT. ? I dont have anything special as far as racks that i have. In fact they were very cheap. But i did go to a granite wholesaler and got 5 pieces of 2 in thick granite cut and using them as platforms for my ARC Ref 6 on one rack , another granite platform for my Rega Isis cdp on the other rack, a granite platform for my Krell FPB 600 that sits on the floor. And 2 granite platforms to put under my B&W 800 Matrix speakers. Also using for now Vibra cones and pucks for my preamp and cdp. 

@elizabeth @geoffkait .....Thanks...... I just did the test with a small hammer while i had my ear on the tube. I did not hear any ringing. I just heard a little bang from the hammer. Maybe it depends on how thin or thick the tubes are. If i did hear a ringing i would of filled them with sand also. But since i did not hear a ringing i will just leave as is.