Step 10: Notes and Disclaimers
This system is very heavy and will probably require two people to move it. I will probably mount handles on the front to make it easier to handle and create some kind of removable cover to protect the drivers while in transit or storage.
The room does not actually act as an enclosure for the woofers as much as it just keeps the front wave separated from the back wave, which is known as an infinite baffle arrangement. If there is some way for the rear wave to reach the front wave (e.g. mounting in the doorway of a room with multiple entrances), this system will not be very effective. The two waves will be 180 degrees out of phase and at least partially cancel each other.
This is effectively a 4 ohm system. Make sure the amplifier used is compatible with this impedance.
I have not yet fully tested the capabilities (or potential dangers) of this system. The heating and cold air return ducts in most rooms in a house should be enough to relieve the pressure induced by large woofer excursions. However, if there are no ducts in a room for some reason and there are windows, be aware of the effect of the pressure on the window(s).
Very low frequencies travel well and are not easily absorbed, so if you are using this system at full or nearly full capacity and have immediate neighbors, they will hear it and probably call the police. Use good judgement .