@atmasphere I absolutely agree, if you are crossing over at 40 Hz. If you are trying to "unload" the main speakers from having to make bass which is particularly important for speakers with smaller woofers, full range drivers and ESLs you have to cross up around 100 Hz . For over a decade I was crossing at 120. The wavelength at 100 Hz is about 10 feet depending on your altitude. Worse even if you are using a steep slope there can be useful output up to 200 Hz. These wavelengths fit into all residential rooms except closets. A lot of the detail in bass and slam comes from this range. I can show you in an instant playing a repetitive bass drum kick switching the delays on and off. I do have a special situation as I designed the house and this room was purpose designed to be a media room. All the speakers and subs form linear arrays and are very directive. There is very little room interference. I essentially have no back wall. It is all broken up opening into other rooms and hallways.
Hoping to order my MA2s in a month or so. I'd say we are 95% of the way there.
Mike

