where to put rack

I like to put the rack at the bass null along the sidewall to minimize airborne vibrations transmitted to the sensitive equipment. But if you have to put it in between, try to put it as far back against the front wall as possible. And if possible, choose a short rack such that the top shlef is below the mid-range driver.

you mean behind the speakers,,unfortunatly my rack is 4 feet high & my suspentionless T/T sits on the top shelf.

....a question rife with double entendre possibilites, but I shan't go there.