Designer:
Ohaple

Project Category:
Home Theater

Project Level:
Beginner

Project Time:
8-20 Hours

Project Cost:
Under $100

Project Description:
This project is a pair of small surround speakers for home theater utilizing Dayton Audio drivers, plywood, maple, and walnut.

The drivers will be the Dayton Audio RS100*4 4″ Reference Full*Range Driver 4 Ohm. These will be driven with a 5.1 receiver. Full range was chosen to keep cost down (one less driver and no crossover parts) and to allow the boxes to be very small for surrounds.

Since we have a laser cutter and CNC available, I was not going to be satisfied with a plain box with rounded corners. This design can definitely be made without CNC assistance, but the CNC helped save us the effort of creating jigs and templates. Even simple cuts will be made on the CNC just to simplify the tools and process. I decided that a 3D-carved baffle and rotational feet would give the impression of more complexity but still only requires 90 degree joints. The initial mock-up reminded me of a TIE fighter, which is why I am naming the system the IONs (TIE = Twin ION Engine).

The full build log can be found here:

http://techtalk.parts-express.com/forum/speaker-project-gallery/1372828-ion-micro-full-range-surrounds-dayton-audio

Design Goals:
To create a pair of great sounding and great looking surround speakers for under $100.

Driver Selection:
The drivers will be the Dayton Audio RS100*4 4″ Part # 295-378 Reference Full Range Driver 4 Ohm. These will be driven with a 5.1 receiver. Full range was chosen to keep cost down (one less driver and no crossover parts) and to allow the boxes to be very small for surrounds.

Enclosure Design:
This project is built using half inch birch ply for the five sides, 3/4″ solid maple for the front, and 1/2″ solid walnut for the wings. Vivvid+ automotive vinyl was used to finish the plywood.

The side panels are each 4.5″x 3.6″. The baffle and back plate are both 5″x5″ to cap off the square created by the sides. Wings are approximately 6″ tall and can be whatever shape you would like as long as the speakers don’t topple over.

Enclosure Assembly:
The wings are attached using threaded inserts and machine screws. The rest of the box is assembled simply by using wood glue and clamps.

Crossover Design:
No crossover is needed since these are full range drivers. The drivers do not perform well under 200hz in such a small sealed enclosure so eq may be beneficial.

Conclusion:
These sound great in the 200hz-2000hz range. Outside of that range the low bass output and poor off-axis response mean that these benefit from a smile-shaped eq. Many will not find this necessary since they are to be used as surrounds rather than the primary speakers in the system. They will look great in most living spaces.

About the Designer:
I am fairly new to speaker design but have recently built 4 pair of speakers with my father. Most of our speakers are 2 way and 3 way designs intended for stereo music listening but these surrounds will form the start of a 5.1 system we are designing.

Project Parts List: