[Slater]

That is my lifelong dream - making CIEMs from custom shells and individual drivers. It is a bit of an an upfront investment to get all of the proper mold and proper shell materials and equipment, which has held me back for the moment (in addition to lack of space and free time). However, once that investment is made, it is a fairly low cost to make individual CIEMs (not including the drivers).

2 very useful guides I found on the actual process are these 2. There are obviously more than 1 way to do anything, but after reviewing these 2 guides, I have a pretty good idea of how to proceed with a very basic set (that doesn't require laser scanning, 3D printing, etc):

1. https://www.head-fi.org/threads/how-a-custom-in-ear-monitor-is-made-photo-journal.885128/
2. Spoiler: Youtube video

 

[Takeanidea]

 

[Takeanidea]

Sometimes when it comes to the perfect fit to achieve the best sound possible, less is more. Introducing the £25 **** EN900 IEMs and note just how little is needed to achieve a custom fit

 

[Slater]

I decided to experiment with the colored thermoplastic dye pellets, which allow you to color the thermoplastic from its default milky white color. They're easy to use - you just use knead 1-2 colored pellets into the thermoplastic until the color is uniform. The basic color kit includes primary colors, black, and brown. So with the basic color kit, you could theoretically make any color thermoplastic you want (including custom swirled effects, rainbow tie dye, etc).

Anyways, for this mod, I used a pair of Estron earpods (sold under their Timmkoo brand).

https://www.amazon.com/gp/product/B07BKQLMTS

They are cheap, have an iOS-compatible 3 button remote, and sound good thanks to their large 14mm drivers.

I like the way earpod style earphones sound, but I hate how they fit. They fall out much too easily.

You can buy small silicone 'skins with wings', designed for Apple Earpods and Airpods. In addition to fitting Apple pods, they also fit on all 3rd party earpods (such as the MEMT T5, these Timmkoos, generic wireless Airpods, etc). And while the silicone wings do help stabilize the earpod in the ear, they really don't keep the earpod pressed into the ear canal opening. Earpods sound their best when they are making a slight seal with the ear canal. When the earpod sound nozzle falls away from the ear canal opening, the sound suffers greatly.

What's needed to solve this problem is a custom-fit 'wing'. This is the perfect application for thermoplastic

Unfortunately, the typical earpod body is too angled and slippery for anything to stick to it without falling off. So I added a small screw to give something for the thermoplastic to anchor to:



(Once the thermoplastic is applied, the screw is completely covered up and can't be seen).

Here's the final product:



The whole process took about 30 minutes, not including the time waiting for the thermoplastic to cool completely. Normally it takes about an hour to fully cool down, but I cheated and went for a short walk outside which cooled the plastic in ~15 minutes thanks to the temperature of 2°C/35°F and falling snow.

 

[gringosteve]

Sorry for the thread revival but wanted to say thanks for all the info on this. I took the plunge and modified my Shure SE215 with thermoplastic. Isolation and fit is now amazing and i actually like the look.

 

[gringosteve]

Key learning:

1. You need way less material than you first expect. Especially if you have small ears like me
2. You need a lot of dye to get black to be black as opposed to grey
3. Get a nice thin piece on the iem and mood gently to the shape by hand. Allow it to cool.. then reheat with hairdryer before fitting into ear
4. This stuff is warm when in boiling water.. but skin meltingly hot when using a hairdryer. Please let it cool a bit before sticking it into your ear. My ear wasn’t burnt but must have been close
5. Coat MMCX cable posts in Vaseline to help stop the molten plastic from sticking to them

 

[Takeanidea]

I like the last point, that's well worth trying, all the other points are valid too, of course, but I've not tried that. Your molds look good, well done

 

[gringosteve]

Thanks for the kind words. New MMCX usb-c cable turned up today too to complete the work on these.

Nor sure if I should do the same to my sennhieser Momentum Free next!?

 

[Slater]

Thanks for the kind words. New MMCX usb-c cable turned up today too to complete the work on these.

Nor sure if I should do the same to my sennhieser Momentum Free next!?

Did you get the Amazon usb C mmcx cable I posted a few weeks ago?

 

[gringosteve]

Did you get the Amazon usb C mmcx cable I posted a few weeks ago?

No this is an AliExpress one. Sounds awesome. I just swapped the tips for Shure comply and they are now perfect.

 

[herrbbiiee]

Sorry for the thread revival, but this looks like a great idea and well worth trying.

I'd like to try this with my sennheiser ie300's, but will try on some cheaper ones first.

Can the mould be removed, ie is the process reversible? I've read that polymorph is extremely hard, can't be smashed with a hammer.

 

[Takeanidea]

Correct. But, with heat, it can be reversed. It needs skill to do it, bit it can be done