Android Passive Amplifier Speaker





Introduction: Android Passive Amplifier Speaker

I made this over the course of a couple of days, pretty easy, just be sure to measure twice and cut once!

Step 1: Getting Started

Cut 4 pieces of select pine (free of knots) to the same dimension. This will vary by phone size and cases etc. I measured with case as I have no plans to disassemble my case with each use.

Step 2: Making Holes

I used a 3 1/4" hole cutter on 3 of the pieces. After I cut one hole, I clamped to the next piece and drew down the drill press to mark the next piece. I then drilled that piece and did the same procedure with the third one. This help ensure the 3 holes line up when gluing and minimizes sanding of the sides later.

Step 3: Glue the 3 Hole Pieces

I next glued and clamped the 3 pieces with the holes and let set for the night.

Step 4: Routing the Sound Channel

Turning the 3 piece glued assembly face down I traced my phone to a depth I felt would hold it securely without it being too wobbly when inserted into the final project. I clamped the work piece down to my bench and slowly and carefull routed a depth equal to the thickness of my phone with case. I then, with a pencil, manually drew the channel from where my phones speaker was to the sound holes in the work piece. I then carefully routed that channel out. Before moving to the next step, I used a drum sander on my drill press to sand the cut circles smooth.

Step 5: Sanding and Gluing the Back Piece

The next step was to glue the back piece on the work piece. First I sanded the face to make it easier than trying to sand it after the glue up. I clamped and let sit for the night. Be sure to use a wet cloth to wipe out any glue in the speaker that squishes out. Afterwards, I palm sanded all sides smooth. I finished with several coats of spray polyurethane.

Step 6: Finished Speaker

The finished speaker amplifies sound quite well. Its a handsome looking block of wood with great pine graining. Serves the purpose when I use it to just play music for myself without a crowd or party. I have attached a video but it doesn't do justice to the sound amplification.

2 People Made This Project!


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I'm making one of these and these instructions were helpful.


Looks great, nice job!

Your welcome. Good luck!

Nice job and nice idea!
Why not attaching an audio file or YouTube video where you show the effect of the speaker? Is it actually amplifying?

Thank you! Im good with wood but not so much Youtube etc. I do have a video so maybe if I can upload to youtube, ill imbed it to my instructable.

If you can text the video to me I can upload it to youtube for you and you can imbed it :)

Thanks Jonathan. I actually looked for it on my phone but its on my computer at home. I did go to Youtube so I think I should be able to figure it out. If not Ill follow-up with you. BTW, there are example videos from others on youtube so you can hear the actual results of these type of speakers. This is the youtube link to a short video of the speaker in action.

Good suggestion! +1