Making a custom in-ear monitor

Intro
Instead of spending $500 - $1000++ on brand name Custom IEMs, I've decided to embark upon a journey to creating my own Custom IEMs.
It's probably going to result in many failures and in the end the cost savings may not even be worth it anymore, but at least it'll be a fun learning experience as well as satisfying for my inner DIY fanatic.

PLAN
1) Prototype Epoxy IEMs, using universal IEM as driver.----------[DONE]
2) Explore making moulds and eventually cast a resin cast.--- [DONE]
3) Prototype Resin IEMs, using universal IEM as driver.--------- [DONE]
4) Explore creating own driver setup. --------------------------------- [Nil]
5) Resin IEMs, using DIY drivers. -------------------------------------  [Nil]

Thats my plan, tentatively of course :)

I plan to build upon this instructable until I reach the final goal.

Step 1: Stage 1: Materials

Materials:
- Epoxy putty (Not the steel variety)
- Vaseline
- Any cheap dremel or drill (Epoxy isn't that hard to drill, I think...)
- A cheap pair of universal IEMs

Optional Materials:
- Acrylic Paint (I used nail polish, would not recommend it for the fact that it worries me to put the result into my ears -.-)
- Clear coat spray paint
- Hot glue for securing IEM to Epoxy shells (I used some gummy yellow shoe repair glue thingy)

Comments

[djjoec]

any type of glue i can use that wont irritate the skin around my ears? Wedding DJ Melbourne Im thinking of using these inside my headphones when i DJ

[jstevewhite]

Great stuff; I can offer a few hints and a caution or two. First, a caution: when pressing stuff in your ears, use a stop. A stop is a small bit of foam or cotton that has a thread threaded through it and dangling outside your ear. This will keep you from inadvertently bonding something to your eardrum and yanking it out with the mold. Maybe. I recommend finding someone to make your impressions for you - I found that I could get a local audiologist to do mine professionally for $40 total ($20/side).

Now - I've been going down the same road you are in various ways. I've discovered something you may find useful: Search youtube for Ultimate Ears, and watch their factory process. They make a mold from your impression, then cast an intermediate positive, which they "clean up" and polish. Then they dip it in some sort of wax or polymer that adds a thickened, shiny smooth layer. THEN they make the final mold. This step seems to be crucial in achieving the isolation you're (we're) looking for.

When you go to make your own drivers, check the Knowles GQ series of drivers. It's a dual -driver balanced armature; I'd almost bet money it's what's in Apple's BA in-ear. I'm working on re-molding my Apple in-ear (balanced armature ones) into a custom IEM. I'll report back when I'm done. if it works well, it gets you a $250-600 set of IEMS (dual balanced armature) for $70 and some materials - and a lot of fun. :)

[TheJoshinator]

Oogoo actually works quite well for the IEM material in my experience. Before you had tried the Oogoo for the mold, I saw this 'ible and was inspired by my lack of epoxy resin to make it from Oogoo. I put small pieces of a plastic drinking straw on my pair of Skullcandy earbuds instead of the rubber tips, cut them to length to make a sound tunnel, encased each earbud in a large blob of Oogoo and squished it into my ear until it was cured. Remove the straw (Oogoo won't stick to polycarbonate or polyethylene plastics, including straws, plastic bags, and most cheap earbud bodies) and there you are. They sound much sharper overall, bass is better, sound isolation is excellent, and they feel wonderful - very little ear fatigue after wearing them for hours.

See if you can find the really cheap, clear silicone caulk rather than the opaque stuff; it seems to be thinner and easier to work with, and you can color it with acrylic paint. Putting less cornstarch in will make it take longer to cure, allowing you more working time with the Oogoo, but it will still cure all the way through if mixed thoroughly.

Also, I may try your method of making a cast of my ear and then making a mold from that, but making the cast with Oogoo rather than epoxy (doesn't rip out as many ear hairs...). With the direct approach I used, it was difficult to get the earbuds placed right, but I suspect that would be remedied with the external-mold approach.

I should note that the Oogoo stung a bit while it was in my ears, but it really wasn't bad. It felt like having hot water in my ear. The silicone caulk used in Oogoo releases acetic acid as it cures, which is essentially concentrated vinegar, so it's not toxic or anything. It started to feel hot after a couple minutes, but that can be reduced by lubricating one's ear with oil or Vaseline because the acid won't get through the lube as much. I wouldn't recommend doing it often, but you should only have to do it once or twice.

Again, great Instructable - I look forward to seeing your continued progress!

[daemon ulf]

wouldst kids clay work, Good Sir? or dost thou think latex of some kind, wouldst work, or mayhap even rubber caulking wouldst work,, but all-in-all 'tis verily a mighty fine 'ible

[ilovegm]

Haha, art thou referring to the impression material or the mould material?

[daemon ulf]

both in fact, good sir..

[PSPerson]

you can get "mold your own earplug" kits at walgreens. I bought one of those and stuck my skullcandy in-ear headphones into it when i was making the mold. This could easily be used in your project..

heres a kit i found on amazon for $9
http://www.amazon.com/Radians-CEP001-T-Custom-Molded-Earplugs/dp/B002E6T7ZM/ref=sr_1_1?s=hi&ie=UTF8&qid=1312867469&sr=1-1

[kretzlord]

there's some good diy sugru (or "oogoo") instructables on the site, for the cost of a tube of silicone (~$2 @ walmart). just a thought. Good luck in your Experimentations!

[Retro Correct]

You wouldn't want to use oogoo, seeing that it is irritating to human flesh.

[kretzlord]

food grade silicon perhaps?

[Retro Correct]

Perhaps, I'm know expert, but that sounds like a reasonable idea; provided that that will still make oogoo. I believe that oogoo requires a specific sillicon (would someone investigate this furthur? I have little experience with oogoo)

[Kaelessin]

i wonder if this could be modified (read: simplified) to create custom fitted earplugs. . . .I've been wanting a pair for when i'm riding my motorcycle to help cut back on wind noise but the commercial ones are outrageously expensive . . .

[ilovegm]

Hmm, without drilling the holes, these are already custom earplugs, but the epoxy material does not isolate well enough to serve that purpose.

Maybe create a silicone cast version?
Probably should make it slightly thicker than the actual impressions to ensure a tight fit and seal...

It'd be way easier to get those DIY earplug kits from Radians though...

[Kaelessin]

Ha! i guess I haven't searched hard enough! those look perfect, thanks man!

[ilovegm]

Glad I could help!

I would have gotten those too, but unfortunately i'm in sad sad singapore, don't get much cool stuff here...

[mrdovie]

I have not tried this, yet, but mixing the Oogoo in a small zip top bag with all the air squeezed out may help with the bubbles and extend cure time. Just cut a corner off the bag to squeeze out?

[ilovegm]

Sounds very feasible...
I'll be trying that out, thanks :)

[sageserver]

Sugru?!?

[ilovegm]

I was thinking of using Sugru too, but epoxy putty was more readily available.