Simplified compact and easy to print 40mm back horn speaker (backhorn)

thingiverse

I used the really useful customisable SCAD file by Chris Hill to make a compact backhorn enclosure for a 40mm speaker and then basically just used the outline it created in SolidWorks to create a new model and simplified/shrink it down as much as possible. You can see from my video that the sound is clearly far better than just the speakers on their own when I hold the side-panels in place compared to without them. https://www.youtube.com/watch?v=UcD5SGdQ0Ug I wanted it to be easy to print without any supports needed so I added in a hex pattern speaker grill and made it so you can easily mount a standard cheap 40mm 3W speaker in there with hotglue. You may need to scrape the inside of the hole a bit or file/sand the outside of the speaker if it's a little tight. I'm using a simple tiny PAM 8430 class D amplifier board with no volume knob powered by a 5V USB cable and simple headphone input jack so it didn't need much space for electronics etc inside. I just epoxied a micro-USB socket in the back and screwed in the headphone port. I added a heatsink to the amp, but it's probably overkill! I wanted a stereo setup so I designed it to have a left and right speaker with a 2x0.8mm sides that prints on the bed and glues together with epoxy. This also makes it REALLY easy to print. There is a hole behind each speaker for the two wires with built-in supports that you cut away with an exacto knife. After passing the wires through the provided holes to the speakers I used hotglue to seal them. There's a larger hole to pass wires through and join the electronics in the back section that doesn't need sealing as it's already isolated from the speakers. The actual backhorn shape is 2mm thick for strength, but the side panels used in my make are 1.6mm thick. I included other versions if people want them to be thicker or without holes when joining them up. I haven't bothered producing different thicknesses of side panels as that's easy to adjust in your slicer. Please note that the one with the hole in it is if you wanted to stack more than two of these together. There are loads of photos in my posted make to show how it all goes together. I redesigned the connector panel and removed any holes joining the speakers after my first print, but didn't want to waste filament reprinting so the backs don't match in the photos. Don't worry, the ones posted here have the improved, simplified back panels and only holes joining the electronics compartment. After testing it all to make sure it worked I just used epoxy to glue the side and back panels on as I have no intention of dismantling this! Removing screw-holes makes it much more compact. It's very easy to print with no supports/rafts/brims needed - but make sure you use layer view in your slicer and experiment with changing the line width to ensure there are no gaps in your walls. I print with anything from 0.44mm to 0.6mm with my 0.4mm nozzle and 0.2mm layer height and I'm always adjusting it depending on the model (I like to get as close to 0.6mm as possible for speed and also improved side/top print smoothness).