Portable Bluetooth Speaker | MKBoom DIY Kit

Hi everyone! So good to be back with yet another speaker project after a long break.

Since most of my builds require quite a few tools to complete, this time I decided to build a portable speaker using a kit that you can purchase easily. I thought it would be a great idea to share a high quality speaker kit that is easy to assemble on your own and sounds great just as well.

I was fortunate enough to have Parts Express provide me with an inexpensive MKBoom speaker kit that consists of the drivers, the KAB amp board with the necessary accessories, port tubes, crossover boards, and the knock-down cabinets which are of great quality. If you are wondering about building a speaker yourself, I highly encourage you take a look at this MKBoom speaker kit.

I have to say that I am very impressed with the overall quality of this speaker kit. From great packaging to high quality of the CNC'd panels, this kit provides all the needed instructions, bolts, screws etc. to help you build a one of a kind portable Bluetooth speaker that you can customise however you like and that also sounds amazing.

Producing clear highs, wide soundstage and punchy and submerging bass from 4 inch woofers is just incredible. It sounds even better knowing that this speaker has been built by yourself.

Since pretty much all that's needed to assemble the speaker is included in the kit, not many additional supplies are needed. I did, however decided to slap on a nice looking leather handle for easier portability of the speaker and screwed on some more robust rubber feet on the underside. Also, since I live in Europe, PartsExpress were unable to ship the 18650 batteries that are included in the kit, so I used my own, which I have purchased from the links below, along with other bits and pieces.

✅ MKBoom portable Bluetooth speaker kit (US/EU) - https://parts-express.sjv.io/NKgBEq / https://bit.ly/3Qk6gSb

✅ Kit without batteries (International Shipping 🌎) - https://parts-express.sjv.io/7m4eKY

🎁 $5 OFF your first App order on AliExpress - https://a.aliexpress.com/_mPN8FLo

Parts:

• 3 X 18650 batteries - https://bit.ly/3J3KCNl
• Leather handle - https://bit.ly/3VItXEE / https://geni.us/jPboqt
• Rubber feet - https://bit.ly/3IjqU2z / https://geni.us/E2PU4
• 16mm M4 screws - https://bit.ly/3v6OKER
• Heat shrink tubing - https://bit.ly/3YRsVsV / https://geni.us/WZeB
• Amplifier knob - https://bit.ly/3WPV0PQ / https://geni.us/TIJibdY
• MDF sealer - https://geni.us/9YyKv

Tools:

• TS101 soldering iron - https://bit.ly/3hQm4PP / https://geni.us/owyDm5G
• Cordless drill - https://bit.ly/2UiMSbL / https://geni.us/A5AZi
• Drill bit set - https://bit.ly/3S3i6zC / https://geni.us/ktAK1M
• Center punch - https://bit.ly/3xslc8u / https://geni.us/o5WBEwB
• Wire stripper - https://bit.ly/34kBgLn / https://geni.us/6epIs
• Orbital sander - https://bit.ly/3I4yBcP / https://geni.us/gHqu0W
• Wood router - https://bit.ly/3I7Aplm / https://geni.us/6okRl
• Router bits - https://bit.ly/3ig7sJv / https://geni.us/oBKry
• Tack cloth - https://bit.ly/3jIEL8m / https://geni.us/Bv64JV

Even though the speaker kit provides clear instructions on how to assemble the speaker enclosure, there are a few point I would like to point out to make the whole assembly process easier:

1. First of all, lay out the crossovers on the bottom panel (D) in the centers of each side. Make sure the speaker leads will be able to reach the front of the enclosure to connect the drivers. Use a small drill bit to pre-drill the holes for screwing down the crossovers. Don't drill all the way through the panel. I used the supplied Philips screws for mounting the crossovers in place. I do not recommend hot gluing them in place.
2. Now that you have the crossovers mounted in place, stretch and bend the leather handle where it feels as a nice grip for you. Then measure the distance across both ends where the bolts go through and mark them on the top panel from underneath. Mark the points with a center punch and using a 5mm drill bit, drill all the way through the panel. Now take one threaded insert and lightly tap it in place of the drilled hole. It will leave a mark of 4 points. Take a small drill bit and drill those point just so slightly to help the threaded insert sit in place. Using a hammer you can now tap the threaded inserts in place. Remember, that they must be on the inside of the speaker (opposite to where the handle is mounted).
3. Use plenty of glue when gluing the panels together and use a small brush to spread the glue evenly. My best advice is to use clamps if you have them. It will help align and tightly glue the pieces together. Unfortunately I did not have any clamps on hand so I used a bit of tape instead to hold the pieces together while the glue dries. Make sure you use a square.
4. Before gluing the top or back panel in place, make sure to connect the 4-conductor speaker wire harness from the amplifier package to the crossover inputs according to the instructions.

Now that we have the enclosure glued up, we need to sand down any rough edges. Since I did not have any clamps on hand to hold the panels in place while the glue was drying, a few gaps showed up after sanding. I highly recommend getting an orbital sander - they are real cheap nowadays and will save quite a few hours of sanding. I then used a bit of wood filler to fill any gaps that were left.

I them marked where the holes would be for the rubber feet on bottom of the speaker. Use a small drill bit to drill them out. I then took my wood router and using a 1/4 in roundover bit, I went around the whole enclosure, leaving the edges nice and round. Once that was done, I used 4 screws and screwed them in place where the rubber feet would go. These screws will act as stands while preparing and painting the enclosure.

Starting from the bottom, I used a MDF sealer to seal the pores of the panels. I purchased my MDF sealer at a local wood shop. Sealing MDF helps save paint and produces a much nicer finish when painting because the surface is no longer able to absorb the paint like a sponge.

Using a sanding sponge, I lightly go over every surface of the enclosure to knock down any dust that had stuck on the sealer while it was drying. It also helps the paint adhere to the surface better. Once the enclosure is lightly sanded, I use a bit of degreaser to remove any dirt and oil left on the surface.

I then covered the speaker holes using some tape and using a tack cloth, I removed any dust leftover on the bottom side of the enclosure.

I used white spray paint which I have applied in a few coats, letting them dry in between. I firstly sprayed the bottom side completely, flipped the enclosure over and finished the remaining sides.

Now that the paint is fully dry, all that's left is to finish the assembly of the speaker.

I begin by screwing down the rubber feet on the bottom and attaching the leather handle on the top. We can now assemble the control panel, which might look a bit messy, but is really simple using the provided instructions in the amplifier box. Using a few zip ties helps organize and tidy up the wire mess, making it look professional and neat. Make sure you take note of the polarity when making connections from the panel to the amplifier.

Don't forget to connect the Bluetooth antenna like I forgot!

Once you have the control panel assembled, slap it on the enclosure, mark the screw holes, drill them out and apply the provided gasket tape. You may need to trim it to fit it just right along the edges. Install the 18650 batteries in to the holder, connect the speaker wire going in to the crossovers and mountthe whole assembly in place using the provided bolts.

A bit of wood glue around the port holes holds them in place better.

Now for the most fun of the fun parts - mounting the woofers and tweeters in place! Put them in place, carefully align them and mark the screw holes using the trusty center punch. Drill the holes out, place the provided gaskets and make the connections to the speakers.

Make sure you double check the polarity of each wire going from the crossover to the speaker drivers.

All that's left is to slap on a volume control knob if you haven't done so and you are all set for a great and rewarding listening experience!

To my mind, this speaker has an incredible value - not only is it not pricey, it is also a one of a kind speaker that you won't be able to buy off-the-shelf at the store since it will be customised with a unique design.

I have this speaker playing some soft jazz tunes while writing this Instructable and can't get enough of the great sound quality it produces.

Hope you give this build a try!

See you on the next one!

- Donny