This was a lot of fun, I used this site to generate my lithophane, http://3dp.rocks/lithophane/ with the attached settings. CHANGE THE MAXIMUM SIZE TO 254mm.
This is the BlueTooth LED... https://www.amazon.com/gp/product/B075RXN74D/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1
Item Model Number: DT-42777
I used PhotoShop with the below settings, I made two strips that were 53.5mm high by 301.59mm wide with a 2mm gap separating them. After scaling, these sizes are a little different but they fit the BlueTooth perfectly.
I printed the lithophane at 0.1mm, using Cura and a Creality CR-10s. I used AutoCAD 2015 to make the files.
You'll have to file a couple of the holes for the inner top a little bit to make it fit perfectly.
You'll have to heat up the top part of the speaker (where the silver ring is at) with a hot-air blower or hair-dryer then lift it up with a spuder tool or a guitar pick and maybe a small flat-head screwdriver. Then snip the connecting wire that goes to the capacitive touch ring, remove four screws then remove the diffuser.
Print out your custom cylindrical lithophane, print out the three parts I made. Place the base part in the bottom (it has to be squeezed in a bit, but it fits and it is keyed at the back), insert your lithophane, then place the inner par near the speaker (with the long skinny part facing downward), place the outer part there with the alignment pegs fitting into the alignment holes. Once you know everything fits perfectly, glue the inner and outer top parts together, then glue them to the litho, then place a couple drops of glue on the printed bottom and insert a couple screws into the top. Let it set, then place a little more glue around the base and tighten everything (I used superglue, a 3d pen should work fine if your patient). I used some strong double-sided tape between each screw on the top and made the strips as wide as the bottom of the speaker grill and used a small amount of the tape to cover the screws (that way nothing vibrates). I soldered the wire to the touch ring and fit everything together. It takes a while but it's very rewarding. Other than print time (about 24 hours), the hardest part was drafting up the parts.
I hope someone has a chance to try this out! I love how it came out! I used PLA, I've tested some with PETG but I'm not good enough with it yet.
I added Bluetooth_Base_Holder, Bluetooth_Top_Holder and Support_Arms (print 3). Since the bluetooth was originally designed in a way that it could be held from the bottom, I thought that would look funny with a lithophane (everything would be upside down). So I designed the base/top/arms so that one could use a piece of 550 cord (slightly melt the end and press it down so that it flairs out a bit, then feed from the inside to the outside). Make sure that you flip all the parts to print properly, some are upside down. Also, I updated the litho maximum size to 254mm (I had the wrong settings from another Thingie previously).