I've always had a question about how people measure room size to determine which sub would be a good fit, especially for those rooms where the actal listening area is pretty small but opens up to other parts for the house. For example, my listening area is about 14'x12', with the TV on the 14' wall. However, opposite of this wall, beyond the 12' listening area, it continues in to a dining area and the kitchen, which is another 15' or so feet beyond. Which dimensions should I use to gauge what sub to get? Ceiling is 8' tall by the way and wood floors throughout. Thanks.