The Encore

The Encore
Design Goals
Driver Selection
Enclosure Design
Enclosure Assembly
Crossover Design
Conclusion
Parts List
About the Designer
- Enclosure Design -

Since one of the main goals of this speaker was compactness, a single woofer two-way design was chosen to help keep the enclosure size to a minimum. Believe it or not, a single 5-1/4" or 6" woofer can produce some fairly substantial bass and can really surprise a person with its full range capabilities. I've built and heard many DIY and commercial high-end 5-1/4" two-ways that really impressed me with their bass and overall output capabilities.

The RS150S-8 has parameters that make it suitable for both sealed and vented enclosures, and for the purposes of this article, I will outline both options. The speakers as built use a small, sealed enclosure of .25 cu. ft. This sealed alignment produces an F3 of approximately 80 Hz-perfect for use with a subwoofer. The Dayton TW-0.25 .25 cu. ft. speaker cabinets are an excellent choice for this alignment, or you could build your own 12" H x 7.5" W x 10" D cabinets.

The vented alignment with this woofer would be the more suit able option for stand alone use in a bedroom or similar situation. In my opinion, one of the tricks to getting "solid" bass out of a smaller driver like the RS150S-8 is to use a vented enclosure that is not tuned overly low. For whatever reason, most of the 5-1/4" two-ways that I have liked best in the bass area have F3s around 60 Hz with tunings around 50 Hz. This helps to create tight, punchy bass that sounds like the bass one would expect from a small speaker.

To get a tuning in this range with the RS150S-8, we need an enclosure of approximately .35 cu. ft., with a 1-1/2" x 4" port. It just so happens that the Dayton TW-0.38 .38 cu. ft. cabinet nearly matches the desired cabinet volume, and would be an excellent choice. For those that want to build their own cabinet, the external dimensions are 14" H x 8" W x 12" D.


Diagram #1