藍(lán)牙低音反射揚(yáng)聲器

This started as a remix from
Edit 2021/02/15:
Check out veion 2. It prints much easier and sounds just as good:
I added STEP files.
There is also an STL for a redesigned front panel. This one can be used in case you want to screw the speaker to the outside of the cabinet.
Edit 2021/02/01:
This tiny speaker is quite amazing with an that can boost the bass! The bass-reflex design works very well.
I added some photos of the speaker. Please bear in mind that I use this one for engineering and testing, not for cool looks. With a little more effort you can make it coiderably more pleasing to the eye :)
Original description:
The original back horn speaker design by guppyk is very good looking but the sound was quite a letdown. The horn amplifies the mids as well and the reflective surfaces sounded like a reverb effect to my ea. I preferred the sound while completely covering the horn with my hand. After a bit of research I think hor need a much larger volume. The desig for this speaker are mostly 70-90cm tall (!) like this one:
So I redesigned the speaker with
a bass-reflex enclosure using BoxSim (fb=96Hz for 1.83l enclosure volume)
M3 thread ierts for the speaker and side panels
curved surfaces to get rid of reverb and standing wave effects
The sound is a lot better, although you have to keep in mind this speaker will never have a lot of bass - at least in such small enclosures. The bass-reflex pipe does its job as expected without amplifying the mids. With a sine-wave-test-sound it works well down to 60-70Hz. Lower frequencies are present but attenuated.
Looking at professional bluetooth speaker desig there are a lot of electronics iide to make small speake sound bigger than they are.
I attached the speaker and 8mm MDF wood side panels with M3 screws and self-adhesive EPDM foam strips to get a good seal all around. Tight seal is crucial. This way I can easily experiment with wool fillings.
A handful of polyester wool iide the speaker improves the sound as well.
The wood side panels only slightly vibrate in the bass range, while the PLA surfaces tramit higher frequencies, too. Perhaps more infill or greater wall thickness would be better. I'm not planning on testing this, it is a long print already.