This project is the design and construction of a high-fidelity Bluetooth speaker. There are lots of cheap Bluetooth speakers available to purchase, but very few that have decent sound and those are very expensive.

This speaker is designed to be attractive and also have great acoustics. High quality drivers were used and the enclosure was designed to minimize internal reflections and provide adequate internal volume to get a low resonance frequency. A bass reflex design was used to maximize the bass response from the small drivers.

The speaker was designed using 3D CAD software in order to get the angles correct. The enclosure is an octagon and the main drivers are angled at 45 degrees. This allows for maximum stereo separation in the minimum enclosure size.

Here are the donor Mission speakers and the BT amp.

Supplies

3/8" Birch plywood

Mission speakers (purchased used at a low cost)

Bluetooth amplifier: https://www.aliexpress.com/item/33052630279.html?...

Sound insulation: https://www.amazon.ca/gp/product/B07RWWQ3GG/ref=p...

Oak veneer: https://www.amazon.ca/gp/product/B001B1AR6E/ref=p...

Step 1: Donor Mission Speakers and BT Amplifier

The amp was connected to the Mission speakers in their original enclosure to test the volume and quality of the sound.

Step 2: Faceplate

A Circle cutter was used to cut out the space for the tweeter in the faceplate and a jigsaw cut out the ports for the bass reflex.

Step 3: Fitting and Bracing the Enclosure

Each piece of the enclosure was cut at the correct angles and glued and screwed together using braces. A centre support divides the enclosure into two cavities - one for each stereo channel.

Step 4: Adding the End Faces and the Bass Reflex Baffles

Two sets of baffles were made for the bass reflex system. One set is fastened to the back of the enclosure and one set to the front. They are spaced to allow about a 2cm gap between them, and each set is about 2cm shorter than the width of the enclosure. This provides a long labyrinth path for the low frequencies to exit the ports. The bass sound of the finished speaker is excellent, much better than could be expected from drivers of this size.

Step 5: Mounting the Amplifier and Adding Sound Insulation

A crossover network from each of the Mission speakers is mounted on each side of the new enclosure and the Bluetooth amplifier is mounted above one of the crossover networks. A small metal panel was made to mount the power cable plug, and on-off switch, and the volume control. Then sticky-backed sound insulation was added to each enclosure to minimize reflections.

Step 6: Video of the Speaker Playing

The sound quality from this speaker is excellent. I have NAD/Adcom/Magnaplanar components in my main stereo and this is not quite at that level, but it is still far beyond the commercial speakers that are readily available.

I finished the speaker in oak veneer (still in progress at this time) and will add edging to it. Supplies have been delayed in shipment due to Covid-19. But I enjoy listening to the speaker every day.

Good luck with your projects.

Step 7: All Done

The red leather edging came in finally so I finished the speaker. I think it looks quite good and I can tell you it sounds fantastic. Played some Dire Straits through it today and am amazed at the clarity, bass and separation.