Are you into unusual subwoofer box design? Keep reading!

If you like cramming a bunch of drivers into a small box, then you are going to love this cube of speakers subwoofer box. It’s basically a passive radiator design using Dayton Audio drivers. Now I’m going to cut directly to the chase. If you want to learn more about passive radiators you can check out this or this article. Also, if you haven’t stumble upon this article through YouTube, then you should probably watch that video first.

Box dimensions

The box was made using 18 mm thick MDF, but you can use plywood if you have it readily available. The overall external dimensions are 340 x 355 x 376 mm (W x H x D). And here are the panel dimensions:

  • Front / Back : 355 x 340 mm (4 pcs)
  • Top / Bottom 340 x 340 mm (2 pcs)
  • Sides : 340 x 319 mm (4 pcs)

As you can see, front/ back and side panels are in double the quantity. That’s because I want to double the thickness of the panels where speakers are placed.

Even though this is a perfectly balanced subwoofer by design, I want to add a bit of mass to it. Having so many large cutouts in the box will reduce it’s strength and rigidity. Double thickness panels in these spot, will help with this issue.

Parts list

There aren’t many parts, since this is a subwoofer, but here is the list with links for both Parts Express and Sound Imports. If you are either from US or Europe, you can choose which one suits you better. The links are affiliate paid links (I get a small commission for no additional cost to you):

Remember that this is a cube of speakers. Make sure you buy 2 active speakers and 2 passive speakers.

Building instructions

There is nothing special about building this subwoofer box. It’s pretty straightforward. The only things that may present some difficulties are the binding posts. Since we stack 2 panels together, there is not enough thread on the binding posts to reach the other side with adequate clearance. In that case make a recess, where the binding posts will go using a large drill bit.

Binding posts recess

Cube of speakers tuning frequency

Changing the tuning frequency of the box is as simple as taking the passive radiators out and changing the number of discs on the back. More discs means higher moving mass, therefore lower tuning frequency. I made 2 measurements: one with 2 discs and one with 0 discs. Tuning frequency is as follows:

  • 2 Discs -> 31 Hz
  • 0 Discs -> 43 Hz

Since there is no other way to reduce the moving mass, 43 Hz is the highest tuning frequency available for this design. Unless you add another passive radiator, but I don’t know why you would want that.

Passive radiator tuning frequency

Here are the frequency responses for both cases. As you expect, better low-end performance for 2 discs versus increased output in the higher frequencies for 0 discs variant.

Conclusion

This cube of speaker is an interesting project. It packs quite a punch in a small package. The power handling is 500W at 4 Ohm. While it’s not a monster of any sorts, it does impress as you might underestimate it judging by its size.

cube of speakers passive radiator

As you can see, I used some veneer to finish the box. However, you can choose whatever finish you like. That’s about it, have fun with it if you plan to build it.