Bothell Sphere Mini speaker

It requires a 330 uF cap inside as a high pass filter, to protect the small driver from lowest bass, so its effect applied at both graphs.

Port tuning is around 74 Hz.

EQ is next:

1. High shelf 800 Hz, -2.5 dB, 1.9 octaves.

2. Peaking at 7700 Hz, -7 dB, 0.39 octaves.

I will solder a hardware filter to apply this EQ

Modeled parametrically in Fusion360, you can adjust "User Variables".

BOM (for a single speaker):

1. Driver - Dayton ND65-8.

2. 330 uF non-polar electrolytic capacitor.

3. Optional - 0.1 uF film capacitor to compensate for the big cap ESR on high frequencies.

4. 2x binding posts.

5. 6x Ruthex M3 inserts

6. 1x Ruthex 1/4-20 insert.

7. 2x M3x8 screws.

8. 4x M3x6 screws.

9. ~500g of PLA filament for the body and posts bracket.

10. ~1g of TPU filamment for the posts gasket.

Next step would be to make it with a Tectonic TEBM65C20F-8 3-1/2" BMR driver.

Through for a small 2.5" driver, you still need a traditional ND65-8 driver, because its Xmax is pretty big at 3.5mm.