The goal: make something that could shake the entire house, walls and floor.
Oh boy… We achieved that quite well.

Acquiring the subwoofer

3 years ago I bought a subwoofer from a local shop, a 12 inches JBL Stage 122D, 250W RMS and 1000W peak, for a very good price.

I had no way to use it at the time because I needed a proper enclosure, so I kept it in a cabinet… until a few months ago, when a friend suggested me to use this website to make a quick and easy ported enclosure design, without having to research anything super fancy or extraordinary.

Designing the box

We used the tool to make the design of this box, setting the resonant frequency to 28Hz, internal volume of 60 liters, and making a wide and slim design to be able to fit behind the sofa of the living room.

Making the box

What comes next is pretty straightforward, I went to buy the wood, got some really sturdy 28mm thick planks. Then we used a circular saw to cut the wood to the right size and carved the hole for the subwoofer using a jigsaw.
This thing immediately started to look enormous. With the width of 1 meter, this box is going to be quite unique and the biggest I’ve ever seen in person.

After gluing the wood and screwing it in place we also painted it producing a very nice and glossy finish.

Internal connections and subwoofer mounting

When the varnish was dry, I proceeded to mount the connectors for the audio input, then attach some foam all over the internal walls, connect the subwoofer to the audio connectors and it was almost done.
The subwoofer is dual coil, so I connected both coils to the input connector to later decide what to do with them (I ended up putting them in series).

Final look and results

The box turned out pretty well, the look doesn’t matter a lot considering it will be hidden behind the sofa, but a good result is always appreciated and the coating will make cleaning and dusting a lot easier.

After some testing I ended up using this 1000w Mosfet Amplifier I repaired and showed in this article to power the subwoofer and connect it to the existing 7.1 audio system of the living room and the TV.

The result is quite amazing, even at low power all the windows of the house start to vibrate.
Turning up the volume a little bit will also make the floor and walls to vibrate, causing the furniture to shake and producing the same result as a low magnitude earthquake.
At the time this article was written, many movie and music nights with friends have been done, and people really enjoyed them.