Stereo Speakers for TV

Eddie Fermanian, Theatrical Design/Technology

INTRODUCTION

Eddie Fermanian
Theatrical Design/Technology and Recording Arts
efermanian@elon.edu
Mentor: Professor Jeremy Hohertz

THE PROBLEM

I noticed that the audio quality of my TV wasn't nearly as good as I wanted it to be. Since it's small, it can't get an audio quality depth that I want when I watch TV, and I wanted to change that. I was looking to buy some speakers, but then I realized I could just make them. I've always wanted to build speakers, and I thought this would be the perfect opportunity to do so.

PROTYPES

First Iteration

I first built a cardboard prototype to map out sizing compared to my TV and driver placement. This helped me physically visualize how the speakers would fit in my space.

Second Iteration

For this version, using the dimensions from my first prototype, I built a version using scrap 3/4" plywood to make a mock-up cabinet. In this version, I built an opening at the bottom to be able to access the inside of the speaker. This prototype was mainly to test crossover frequencies and make sure my parts were working. The biggest issue with this prototype was that, because of the way it was built with an open bottom, it didn't have as nice a sound as it could have. I also tested the frequency response and used crossover components to try to make it as flat as possible.

Speaker frequency response from both tweeter and woofer

Testing Second Prototype using audio-grade inductors, resistors, and capacitors.

Third Iteration

I made another prototype with plywood to test my speakers in stereo. In this version, I made the bottom and the back part removable in order to access the inside. This one change made a huge difference in the way the speakers sounded. This version is most similar to how the finalized version would look and sound.

Circuit diagram of the inside of the speaker

Final Build

For the final cuts, I used the CNC machine in Elon University's Scenic Shop. This cut all of my pieces for me to make sure everything was precise. I then stained my wood with a dark wood stain, and use wood glue and clamps to put it together.

Challenges

I originally planned to have part of the wood cut out so that my drivers would lie parallel with the surface. However, the cuts I made were slightly off so the drivers didn't fit in. I ended up having to scrap this idea, but I had made the cuts with one of my final pieces of wood. I ended up just using the other side of the piece and having the drivers stick out of the wood a little bit.

Left: The offset cuts on the front of my speaker cabinet. Right: The other side of the speaker used for the final cabinet

MATERIALS AND TOOLS

Hi-Vi Woofer
Peerless Tweeter
16 gauge speakerwire
Audio grade resistors
Audio grade capacitors

For the cabinet:

3/4" plywood
Titebond Wood Glue
Silicone latex
Woodstain
Walrus Oil (for a finishing coat)

For this project I learned how to use:

CNC Machine
Router
Soldering
Table Saw

RESOURCES

I mainly based my build off of speaker kits, and watched other people build them to get a general idea of how to build as a beginner.

I wanted to personally thank my sponsor, Jeremy Hohertz, for being an incredibly helpful resource to me as I was very new to speaker building. I also wanted to thank Elon University Scenic Shop, Luis Silva, and Anthony Cacchione for all their help with building my cabinets.

What's next?

I hope that these speakers will last me for a while. However, the main purpose of this project for me was to learn the process of speaker building, without expecting a perfect project at the end of it all. I am now more confident in my abilities in speaker building, and hope to build more in the future. I would love to, in the future, revisit these speakers and revamp them as I gain more knowledge and experience.

CREATED BY

Eddie Fermanian