Project Time: 8-20 hours
Project Complexity: Novice
Project Cost: $100-$500

Design Goals
To create a Bluetooth player significantly better sounding and less expensive than those available in department stores.

Driver Selection
This project is based on the “Overnight Sensations” speaker kit from Parts Express. The 2-way system uses the HIVI B4N 4” midbass and the Dayton Audio ND20FA-6 ¾” neodymium dome tweeter.

Enclosure Design
Ported box supplied with the kit.

Dimensions: 9″ H x 6″ W x 8-3/8″ D, with a volume of roughly 0.16 cubic feet (4.5 liters) and is tuned to 53 Hz using a 1-3/8″ diameter port that is 6″ long. Enclosure designed by Paul Carmody.

Enclosure Assembly
Precut wood components were dry-fitted then assembled with Gorilla Glue. The backs were screwed on to provide access for the drivers and crossovers.

Crossover Design
The crossover was built with the components furnished with the kit, and according to the design included. For this version, the circuit was built on 1/8” G-10 stock and fastened to the inside floor of the enclosure using screws and standoffs.

Integration
The LePai LP7498E amp was sandwiched between the two speaker assemblies and secured with industrial Velcro. By placing the power supply at the bottom, there was space in between to store the power cord. The speaker assemblies were also secured together by bolts under the amp and the (drawer pull) handle at the top, resulting in a robust unit with no tendency to rattle or misbehave. Total weight of the finished Boom Box is slightly over 14 lb.

We considered battery power as some of the players have, but our listening is always near a 120v. source and the added cost and weight of a battery system were soon rejected.

Conclusion
Awesome sound!

I am enjoying using the Better Boom Box very much, and I believe the design goals have been easily attained. The cost to build was $228.00, which does put it in the high range for the commercial players, but still way under the Bose Soundlink II system which comes close, but does not sound as good.

The Overnight Sensations are great performers, and the LePai amp with the integrated Bluetooth is a great choice for this application. To sum up, we wouldn’t change a thing, except possibly to get a little wilder with the cosmetics.

About The Designer
A lifetime electronics hobbyist and professional. Graduate Electrical Engineer recently retired from a major aerospace corporation. My current interests are with vintage and tube type electronics. I enjoy helping our local musicians keep their amps sounding great, and build amps myself as time permits.