This is part 1 of the 'LLL'. I still need to finish the PCB that goes inside, that's why I'm doing the video in parts.
In this video you can see the basic design and mechanical construction of the speaker. More advanced acoustical and electrical design plus assembly will be in the next parts.
Download link for the CAD file can be found in the last step.
Step 1: WinISD
I choose the Dayton ND65 for its broad response, low weight and decent price. I calculated the needed airspace with a simulation program 'WinISD'. I went for a Q=1 sealed enclosure which is a good compromise between bass, size and a flat response. I'm designing a PCB with onboard DSP, which I can use to boost the response using PEQ when the excursion allows for it (lower volumes). If you want to use a regular non-DSP amp you can leave it as is, but bass will be lacking a bit. Especially when you also don't use a baffle step correction circuit.
You can download my excelsheet for calculating airspace here:
After you enter Width, Height, Wood thickness and Corner radius it will calculate the needed airspace plus the total amount of layers (including back and front) .
Step 2: Lasercutting File Design
With the parameters from the excel sheet in the previous step I designed a model in Fusion 360.
I usually start by defining the parameters, then building the model up step by step. Once it's finished I make a baseplate and lay out all the faces on the baseplate. Then use "project -> include" to make a new sketch on the baseplate face and export it as DXF. The DXF file can be perfected (line width, color, layout etc) in a 2D program (like InkScape).
Step 3: Realisation
The local FabLab has a lasercutter which can be used by students. Total setup time was only 25 minutes, of which only 7 minutes is actually cutting. I could get all parts from one 730x430mm sheet with room to spare.
Here is a download link to the Fusion360 CAD file:
In the next part I'll be assembling the parts and go more in depth on acoustical and electrical design. Make sure to subscribe :)