Full build plans for a 2.1 home boombox

Here’s the deal! If you want to build a 2.1 home boombox, keep reading. Reading this article won’t be enough. You have to watch this YouTube video in conjunction with reading this article. In the video you will get all the visual queues on how to build the box. However, inside this article you will find all the numbers regarding the box size, and also all the items that you need. Furthermore, I will include some tips about this project that were maybe not mentioned in the video. As a result, I’m going to keep it concise, with just numbers and stuff that you need to actually build this DIY 2.1 home boombox. Maybe add some conclusions at the end.

Box dimensions

First of all, let’s talk about the material I used. It’s 10 mm thick MDF. 10-12 mm thickness I think is the sweet spot for this build. You don’t want to make it too thick, otherwise it would be too heavy (MDF is very dense). But also, you don’t want it too thin, otherwise the box will resonate to unpleasant levels. I do use some damping material, to stiffen up the box. I highly encourage you to do the same.

2.1 home boombox

Just above we have a mock up of the box. The box has 3 inside chambers. Two sealed chambers on the left and right, and one bass reflex chamber for the subwoofer in the middle. On top you can see 2 bass reflex ports and the handle. I feel that you might be concerned that the handle is not centered along the box. OCD is kicking in. Don’t worry. The handle must be closer to the subwoofer, where most of the weight is. Otherwise the box will teeter uncontrollably. Here are the panel dimensions:

  • Front / back: 487 x 222 x 10 mm (2 pcs)
  • Top / bottom:  487 x 190 x 10 mm (2 pcs)
  • Sides / Inside separators: 202 x 190 x 10 mm (4 pcs)

Besides the dimension of the overall box, here are some pics describing which things goes where, cutting diameters, position of the speakers, ports etc:

Back - amp cutout - 2.1 home boombox Front baffle Section - home speaker box

The images should be quite self explanatory on how everything goes together, even though it’s just a rough sketch up.

Sealing up the plate amplifier

Some plate amplifiers exhibit air leakage. This one is no exception. Air leakage is quite low. However, it’s not something I would brush off, as it’s noticeable in certain conditions. I might of gotten a bad example, but I would suggest not taking your chance with it.

How to design loudspeakers - video courses

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Acoustics 101 : Speaker design basics and enclosure design
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Acoustics 201 : Loudspeaker measurements
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Loudspeaker engineering : How to design speaker crossovers

If you watched the YouTube video, you saw that I tried to make some sort of enclosure for the amp, using some sound deadening material. However, results were not satisfactory. As a result, I encourage you to do some sort of enclosure using some 4 mm MDF.

amplifier enclosure Just above you have the exploded enclosure of the amp. The black rectangle is the back of the plate amp that goes inside the box. Anyway, you just put these panels together.

Dimenions:

  • 140 x 40 x 4 mm (2 pcs)
  • 130 x 40 x 4 mm (2 pcs)
  • 148 x 130 x 4 mm (1 pcs)

If you don’t have any 4 mm MDF and only have some 10 mm thick scraps. Here are the dimensions:

  • 145 x 40 x 10 mm (2 pcs)
  • 147 x 40 x 10 mm (2 pcs)
  • 165 x 147 x 10 mm (1 pcs)

Make 3 small indentations, for the wires to pass through to the speakers, and problem solved. No more leakage for sure.

Crossover design

Schematic on it’s way:

crossover design

Nothing much to comment here. This is the crossover design between the tweeter and the mid-bass driver.

Parts list

Up next, we have the parts list for the 2.1 home boombox. This is excluding the finish, of course. It’s your decision on how you want the speaker to look. I used some paint / veneer combo. The parts list contains affiliate links. This means that I make a small commission if you make the purchase, with no additional cost to you:

Even though the items are not exactly the same, from different suppliers, they are compatible. Some speakers will be hard to find. Like the HDS midbass driver. If you are asking if you can use some other drivers that looks the same, the answer is a sound no.

Final thoughts

My honest opinion is that this speaker is exactly what it is. A 2.1 home boombox. You want to throw a party at your house. This thing has got you covered. You can blast this thing to the max with no worries. Since the speakers are high impedance the amp will not get to carried away. But you will have trouble talking to someone else at full volume. Those HDS speaker are 4″ beasts. I like them so much. Shame that they aren’t easily found on stock. Let’s look at the frequency response:

frequency response

As you can see the response is super flat. It looks like the roll-off is kind of early at 100+ Hz. However, this is a home boombox. You will be playing it inside. And the bass will be boosted by the room, to even things out. A pair of those HDS Peerless drivers will easily outperform the single subwoofer. You can DSP the response and make it flat till 60 Hz, but at the expense of raw output. However, this is not a compromise you should make, since the speaker is meant to be played indoors. The bass will be balanced inside and the output is necessary for a successful party.