Boom Box: Sound Engineering a Better Speaker

December 1, 2017 @Technicavolous Tinkering, Tutorial 0
Boombox: Building a Better Stereo Boom Bonnet

To improve the sound of Hardkernel’s Stereo Boom Bonnet (https://goo.gl/TrDU8u), I went to my local hobby shop and got an “assortment pack” of styrene which happened to have some .080mil sheets and some tubing in it. I also purchased a little styrene solvent for welding. I did everything by eye, so some of the corners are not square, but this is intended to go into another cabinet, with only the face plate showing through. When it's complete, I'll glue a piece of cloth over the front and remount the speaker with hex head screws exposed. The boxes will be for acoustics and vibration control. If I were to make the boom box a standalone cabinet, I would probably make it about half as deep, but I chose this size because of the depth of the housing cabinet. I don't think there would be much sound difference with a longer tube.

One thing not shown in the pictures is shredded cotton balls. When the project is complete, I'll have the wires extend to a connector on the back, and the entire box will be loosely stuffed with pulled cotton to make a baffle, in order to prevent a “hollow box” sound.

I am deliberately leaving out measurements, since they don't matter much. I think it would be better to replace the tube with a simple flat sheet spaced up from the bottom about a quarter diameter of the speaker and spaced from the back about the same length. You can find designs all over the Internet for various chamber designs and ideas if you want to go more in-depth.

Boom Box : Sound Engineering a Better Speaker Figure 1 - I just set the little board over my cut panel and marked it with a sharpie
Figure 1 - I just set the little board over my cut panel and marked it with a sharpie

Boom Box : Sound Engineering a Better Speaker Figure 2 - Closeup of the tube attached
Figure 2 - Closeup of the tube attached

Boom Box : Sound Engineering a Better Speaker Figure 3 - Another view
Figure 3 - Another view

Boom Box : Sound Engineering a Better Speaker Figure 4 - Top view with the front panel in the almost complete box
Figure 4 - Top view with the front panel in the almost complete box

Boom Box : Sound Engineering a Better Speaker Figure 5 - The project ends up a sweet looking and great sounding box
Figure 5 - The project ends up a sweet looking and great sounding box

Do something like this with any speaker, including the Stereo Boom Bonnet, and it will instantly sound better. To experiment with the sound, I inserted the front panel in backwards since I haven't extended the wires yet, and the sound was amazing. It tries to do a little bass, not much below 100Hz,but if I put my finger over the tube most of the bass goes away, so the chamber appears to be working like it should. Once the wires are extended out the back and the tube is in the box properly, it should give a tiny bit more bass.

Boom Box : Sound Engineering a Better Speaker Figure 6 - Inserting the front panel backwards improved the bass response
Figure 6 - Inserting the front panel backwards improved the bass response

For comments, questions and suggestions, please visit the original post at https://goo.gl/yyp22n.

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