build to the larger rec box specs per kickers website, a friend of mine ran these and they handled a good deal over rated in a very large box.
i wanna say we had 7.5-8 cubes tuned to 34hz. They did very well on 600rms each
yup bout 7cubes mid 30s freq....that's what i have mine at...check mah sig...gets pretty loud off a hifonics txi1508d i haven't metered my new box yet but the prefab i had them before was about 2.5-3cubes each high 30s freq hit a 140.2 bassrace.