Here I am sharing my experiment with the result that lead to PK Hearts.
To replicate this You will need a few more tools and parts.
Part list is on the bottom.
The story:
I have experimented with the shell I showed in this post. After the second attemt to finish those damn mmxc connectors on the cable, and two broken front cover, I found my eyes pop open when I heard the driver in that. I have tried all my shells with the 14.8mm titanium driver, until I have just found out this particular driver likes open back, with very little damping. I have measured the vent on the blue metal shell, it is 6mm in diameter. So, this was my target vent area.
The driver is called "14.8mm 32 Ohm Speaker Unit Flat Earphones DIY Titanium Diaphragm Earbuds Drivers 116dB"
Link: here. If the link stops working, then search for the title above.
The cover will not fit PK shells! It needs a modified original PK shell.
If You have read my post about the blue metal shell, You already know that You can use that without replacing the cover. Just don't try to remove it.
I turn back to the PK shell, as I will rather direct solder new cable anytime than make those damn mmcx connectors again.
So, back to the PK shell.
I measured the vent holes, and calculated the vent hole area.
You see, the original vent is not sufficient enough, not even close.
But I did not want to drill a 6mm hole on the back, that would have been look dumb.
I had to find shapes, and calculate the total area to match the 28 sqmm hole.
Here are some expamples.
I wanted to have something "final" not just messing with a shell. So I drawn shapes on the shell with a pencil.
I also needed to be able to measure the area, so I started with circles and squares (rectangles).
On the last two You see how the heart shape came together with aproximated area.
There are other shapes You can draw, of course, until You follow the vent area numbers.
I am interested in Your ideas, if You have drawing skills, and able to measure the drawing area as well.
The vent cover / damping is thin felt glued in, I used black and red to mimic playing cards.
The audition result is very impressive. I have always heard "unheard" potential in this driver, but until this could not make sound it this good.
@rprodrigues
The cable I use is available with bending jack only in black.
I have asked the store for other colours, but no other is available than black.
These are the parts needed:
- 2pcs PK shells
- 2pcs 14.8mm Titanium drivers
- 2pcs salvaged PK or Docomo front covers
- light damping material
- semi finished cable (or You make it)
You can buy these on Aliexpress on the links above.
These parts may not sold in 1pcs quantity, so the total BOM would be ~€36 +VAT excl. shipping at the moment if You do not already have parts.
Tools I used:
- PCB drill or dremmel
- Various drills and routing heads around 0.8-1mm
- measuring caliper
- pencil
- calculator
- craft glue for the felt
final notes:
The PK shell in this article needs the cable tunnel and bass ports to be drilled as well.
The bass port is not open on the end, You need to drill it open, and the cable tunnel depending on Your cable diameter.
It is a good DIY project. Have fun!
It has seemed like a great job, in fact the way to approach it to achieve the desired result is outstanding, in the graph I see that it is superior to transparent film in the low range, and this for me is exceptional, since it is a controller that I like much.
Thank you very much for sharing your work.
