[imbeaujp]

REW was useful to me to verify the cross point between my subs and my mains. Make a mesurment with your subs, then add the mains. You will then see if the mains interfers with the subs, sometimes they are not in phase and they cancell or boost each other. In my case, I adjust the sub distance (delay) by one feet increments and look at the graphs. Just one feet delay could add or remove some dips. Here are some examples :