Due to drums not being able to be turned down, yes, it is necessary to rehease with high volume, the drummer in my band has a yamaha 10 peice road kit. with about 15 cymbals surrounding it. What we do with him was we made some big 5 foot wide by 5 foot long wooded blocks wrapped in carpet leaning against the sides of the kit. it may help to face the drum to a wall too..
I've had many problems you are having to, but I got around it!!
