Designer:
TITMAS

Project Category:
Portable Speakers

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
Under $100

Project Description:
The Macanudo is a 15 watt battery powered Bluetooth speaker box housed in an authentic Dominican cigar box.

Design Goals:
With this project i wanted to incorporate as many re-purposed items as possible, aside from the electronics.
Small form factor with an appropriate audio quality with good battery life/portability.

Driver Selection:
Part # 292-634
Visaton FR 58-4 2.3″ Full Range Speaker 4 Ohm

Enclosure Design:
Being that the enclosure was an existing cigar box limited in size all of the design elements were mostly related to selecting and laying out the internal electronic components to work within its predetermined size.

Enclosure Assembly:
The cigar box was constructed of 5/32″ (4mm) hardwood plywood laminated with a paper logo. (typical cigar box materials) which doesn’t lend itself to good audio quality or solid construction/modifications. So my first step was to build a box within a box out of of 1/2″(12mm) and 1/4″ (6mm) MDF. This would deaden the box as well as give me something to attach the components to by way of screws and PC standoffs thereby eliminating the hot glue method of construction. Since the new combined thickness of the box was greater than the reach of the threaded shafts of the volume pot, push buttons and LED lights i decided to re-purpose some old PC board scraps as control /mounting panels. This made the assembly much simpler and efficient as well as adding an interesting design feature.
The two different speaker grills were made from a scrap of 1/4″(6mm) chicken wire and soldered copper wire.
Foam gasket tape makes the lid as airtight (despite the gaping hole where the 5v USB power port penetrates the box) as possible while still being accessible.
I used a length of automotive fuel line hose with a length of 2AWG copper wire inside to make the handle and secured it with 1/2″(12mm) copper pipe nipples that were flattened over the ends of the hose and drilled and screwed to the box.
I chose the DTA-2 amplifier mostly due to its size to power ratio as well as the integrated yet remote volume pot.
The BT connectivity was provided by a Tinysine 5v BT receiver. Chosen for its small form-factor, reliable operation (up to 40′) and 5v power requirement. To eliminate the audible noise due to using a cheap noisy buck converter and having a shared ground between the amplifier and BT module i used a 5v to 5v isolated converter in line after the buck converter but before the BT module. Im not sure if that the correct application for it but it completely eliminated any noise in this particular application.
The LBB-3 battery board was chosen because of its efficiency/safety/all in one convenience features and accessory LED’s.

Crossover Design:
No crossover was used as the only two drivers used were full range.

Tips & Tricks:
On a project this limited and pre determined in size it was very important to know exactly how all the parts and pieces would fit and function together before i started drilling holes and installing the components. To that end i took lots of measurements and did quite a few mock-ups with all the parts to ensure a successful project.

Conclusion:
This was an interesting and fun and somewhat challenging project to build. Much effort went into getting the layout figured out so that everything worked together and within the size constraints. I think i did and feel like i accomplished my goal.
The final project looks and sounds quite acceptable for the nature of this project.
Room for improvement? Yes.
Seeing how the paper exterior is quite fragile and susceptible to damage i should of laminated the entire exterior with some clear vinyl adhesive sheet before modification and assembly.
As an aside, i should really invest in a better camera than the cheap POS cell phone camera that i used and take more progress photos.

About the Designer:
48 year old carpenter/cabinet maker/tinkerer/music lover. I love building stuff. Be it a huge custom house or a humble little wooden keepsake box. Throw in some electronics or anything that plays music and i’m a happy guy.

Project Parts List: