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

Driver Selection
I picked the Dayton Designer Series 4 inch woofer for the specific power requirement, good linear excursion, and the very exact specifications for the box size that were provided. To compliment it I went with the Phenolic Ring tweeter. I really just wanted a different look for this build and no fancy dome tweeter plus it had strong reviews.

Enclosure Design
Fifty plus years ago my grand-daddy started toying with speaker building. After a search of the old attic we found out that he did his work through trial and error to get the box just the way he wanted it. He knew from the beginning what the design was going to be but not the ratios. The design was for a box that has an L shaped vent port that is open at the top inside the box and exits at the bottom front. The vent is the full width of the box and does not taper or expand towards the exit. He eventually came up with a ratio for the thickness/height of the vent to the size of the box. My first build using his design was incorrect on the ratio because it wasn’t until much later that I learned about it. As a result the boxes weren’t tuned as low as I would’ve liked. Also, as a result of the vent port I’m forced to mount the binding posts on the side of the box. A word on the wood that I constructed the boxes out of; it’s called Osage. It’s naturally yellow in color. It’s also a very dense hardwood, perfect for speaker building. With the help of a friend I made it into .5-inch boards. Then put a simple clear spray coat on the boxes.

Amplifier/Crossover Configuration
The amp is a Dayton DTA-100A. I bought it in conjunction with my driver selection in a perfect marriage of amp to speaker specs. The speakers are crossed-over at 4.5kHz due to the exceptional mid-bass quality of the 4-inch woofers.

Conclusion
These speakers are tuned to the maximum potential (to my ear) of the bass of the woofers. The box design allows for the resonance you would expect from a closed box, but when the bass is pushing the woofer to its max you get the compression and reflex you would expect in a ported box. Yet the punchy bass retains its quality and tone due to the resonance chamber.

Project Parts List