This is weird. A few years ago, I purchase a new front bass drum head. I wanted a white, ported head, so Aquarian seem to have what I needed. The head would not fit on any of my 3 Ludwig bass drums. One bass drum from the 60's and two from the 70's. Tried the Aquarian head on a Ludwig bass drum just a year old and....... same issue!! It was not a problem with the hoops, it was the Aquarian head !!