SpecificationsI'd like to add that necessary port area is dependent on how much air you will be moving, so cone area alone is not enough information. If your talking 4kw and 50mm of xmax then you'll likely need more port than either of your options offer. However, in most scenarios 2 6"ers should be adequate.
It's for the RD HeavyweightV2do those numbers seem odd to anyone else? o/s? trying to picture it....