DIY in-ear monitors

[ignotus]

Hi there,

This is isn't strictly edrum-related, but I thought it might be of interest as it's a piece of gear many of us use with our kits and elsewhere.

I found an incredible thread where they describe in detail how to make your own custom IEMs; shells, driver combinations, crossovers, the works: http://www.head-fi.org/t/430688/home-made-iems. As it was my first go at it, I decided to keep it simple by buying a universal shell that's a Shure replica, and a driver combination that's used in commercially available IEMs (the Westone UM Pro 30 among others), and comes with its own crossover circuit. All you need to know is how to use a soldering iron; other than that it's really quite simple.

This is the driver, the GK-31732, a triple driver with its ready-made crossover circuit:
IEM_1.jpg

First, I fitted a small (about 3 mm) length of tubing to each nozzle on the drivers to clear the way for the sound through a small piece of poron foam used to seal the drivers against the shell sound chamber/tube:

IEM_2.jpg
The tubing came as a gift with the drivers so it came in pretty handy. It slips tightly over the nozzles and doesn't require adhesive. I punched a couple of tiny holes in the foam with a multimeter lead, threaded the tubing through, attached it to the nozzles and then trimmed it flush with the foam.

Next, I soldered a couple of wires (scavenged from a broken pair of cheap earphones) from the little solder pads on the crossover circuit to female mmcx connectors. Positive to centre pin and negative to outer pin:
IEM_3.jpg
Then, I squeezed everything into place. It's pretty tight and no glue or adhesives were required:
IEM_4.jpg
In order to adapt the sound signature to your taste, there are these little sound dampers that go in the earphone nozzle. They come in different colour-coded values and are used to tame the high frequencies (and let through lower frequencies), as BA drivers apparently tend to have strong highs. I looked at what others were using and bought white and green dampers, and after some testing decided to use the green ones:
IEM_5.jpg
http://es.aliexpress.com/store/product/High-quality-C0-Repair-DIY-Unit-Housing-Shell-SE535-se425-se315-se215-W40-Earphone/333670_32499329423.html?spm=2114.30011108.3.27.LkI lSt&ws_ab_test=searchweb201556_0,searchweb201602_4 _10037_10017_10044_10043_507_10032_10042,searchweb 201603_2&btsid=832b0778-a57f-430c-86cf-2249bc0bfa32http://es.aliexpress.com/item/Free-Shipping-2pcs-pair-DIY-Earphones-GK-31732-Experience-Balance-Armature-Speaker-Receiver-Earphone-Accessories-from/1000001308317.html?spm=2114.13010608.0.81.kNzP49http://es.aliexpress.com/item/NEW-MM...08.0.89.kNzP49http://es.aliexpress.com/item/Unidad...08.0.57.kNzP49http://es.aliexpress.com/item/Earpho...08.0.65.kNzP49
IEM_6.jpg

[JmanWord]

Great job, those look completely professional!

Not sure what kind of ear tips you are using with your IEMs but I saw a post on another forum about making custom DIY molds, and did that for my Westone UM2 IEMs and the molds made a huge dif for me. I would never have gone through the process or price of getting the custom molds built for these. But that inexpensive DIY was well worth it. I ended up adding the flanged rubber tips to mine later and they don't fall out of the ear and seal all the sound in quite nicely. https://www.vdrums.com/forum/advance...tone-um-2-iems

[ignotus]

Hi Jman,

Thanks. Yes, I remember reading your thread and I probably will look into doing something like that. That said, I do get a pretty good seal with my IEMs (I'm using comply memory foam tips) and they stay put no matter what. Was there also a significant difference in sound quality using the molds? Or is it mainly for the sound isolation? Anyway, thanks for the link, I'll have a look at it again.

[JmanWord]

Hi Jman,

Thanks. Yes, I remember reading your thread and I probably will look into doing something like that. That said, I do get a pretty good seal with my IEMs (I'm using comply memory foam tips) and they stay put no matter what. Was there also a significant difference in sound quality using the molds? Or is it mainly for the sound isolation? Anyway, thanks for the link, I'll have a look at it again.

As far as the tips, that really is what works best for you. I originally was using the foam, later tried the silicon triple flange type and those are what worked for me. Even with a good seal with standard tips like the foam or those silicon flanged I do believe the custom molds makes quite a difference. I don't think you really notice how much sound is leaking until you try the custom molds that basically seal the entire IEM into the ear. One thing that is a tiny pita is it takes a second or two longer to put the IEMs in the ear with the custom molds, because they are formed and copy your ear inside. So you pretty much place them in and make sure you get them seated correctly. I have the IEMs and some great headphones sitting at my drums ..... If I am just going to test a trigger or new sound for a minute or 2 I just stick the headphones on, but if I am going to sit down and play for a while I normally stick the IEMs in. J

[Viperr]

Those look very professional. If only I had more time.... One more thing to put on my to do list. I hope we get lots of bad weather this winter.

[ignotus]

Those look very professional. If only I had more time.... One more thing to put on my to do list. I hope we get lots of bad weather this winter.

They look professional because in reality all I had to do was assemble a few parts - other than the piece of foam all the other components are ready-made, so at the end of the day, unless you really mess something up you have guaranteed professional results .

All it takes is about half an hour. It took me more time to find the parts and buy them than to put them together... What made me hesitate before taking the plunge was actually the cost of the materials; it's a hefty sum that can go up in a puff of smoke (literally) if you're careless, but anyone handy with a soldering iron should have no problems whatsoever.

Just a couple of comments after the first few days using them:

- It turns out the shells are ever so slightly too small for the drivers - they initially snapped shut, but after a couple of days the side of the shell closest to the nozzle and furthest from the screw opened by about 1/2 mm due to pressure from the big driver. I applied a tiny drop of loctite and now it seems to be ok. I think these shells: https://es.aliexpress.com/store/prod...5-4618e2b029ef have more space inside them as they don't have the screw. The downside is you have to glue them together and repairs will be more difficult. I'd still stick to the ones I have.

- The hole where the screw goes in has a slightly pointy edge that needs sanding off. Nothing major but it could make it uncomfortable it left there.

Other than that couple of minor issues I couldn't be happier with them.

[ignotus]

Hi,

I decided to re-shell the drivers in another housing as the ones above had a couple of rough edges and I also wanted to experiment a bit with a different setup to see if it made a difference. I bought a pair of dirt cheap IEMs on Aliexpress, gutted them and replaced the internals with my triple BA driver setup. This time, I used separate tubes for the high/mid drivers and the low frequency driver, each tube with its own acoustic damper. I also separated them (they come epoxied together) and placed the mid/high close to the nozzle, and the LF driver with a 4 cm tube to enhance bass. It was a nightmare to fit everything in and I almost ruined one of the drivers, but the end result sounds spectacular, significantly better than before, and I haven't even got some proper foam tips for them yet. Although they did sound pretty good before, the highs could be a bit too harsh sometimes and the bass lacked some of the oomph that dynamic drivers have. Now they just sound astounding across all ranges. I have some Shure 215s for comparison, and while the previous DIY version surpassed them in everything except bass, now the Shures sound like pound shop buds in a side to side comparison. Yeah, you can tell I'm happy with them
IMG_20170616_181703~01.jpg

[ska]

Hi! Love the post and I'm about to dive in. Really appreciate your documentation, especially the links and pics. Some quick questions regarding your last post with where you used a different case and separate tubes for each driver.

• Did you use the same green acoustic damper for both the woofer and mid/hi drivers?
• It looks like the two pieces of tubing are different colors. Is the tubing colored (if yes, can you provide some details) or is that the color of the acoustic dampers transmitting through the clear plastic tubing, or...?
• Did you use the same MMCX connectors or did you use the connectors that came with the dirt cheap IEMs?
• What 's the translucent white compound around the sound tubes?
• Do you have a link to the dirt cheap IEMs on Aliexpress or have a suggestion on an alternative that might avoid the fit challenge you mention.

Thanks again for posting this!

[ignotus]

Hi,

Sorry, I seem to have missed your post. It's been a couple of years since I made these IEMs but I'll answer to the best of my recollection:

- I *think* I used a green damper for the woofer and a red one for the mid/hi drivers. I definitely used a different one in each tube.
- The two tubes are the same - I reckon it's just how the photo came out. The dampers are down inside, near the spouts of the drivers. I later used the little metal mesh that came with the cheap earphones to cover the tube openings and prevent earwax from getting into them.
- I used the MMCX connectors that came with the cheap earphones. I still regularly use these IEMs and they're holding up fine.
- That white stuff is just hot glue. With the tubes protruding out through the spout, I filled in the gap around them with hot glue and then trimmed them. It made a huge difference to the sound, because otherwise I think the sound was getting reflected back down the gap and they didn't sound good at all.
- The ones I bought aren't there any more - these seem to be similar. As they come with a dynamic driver, you have to cut out the circular plastic chamber the driver is embedded in, otherwise the BAs won't fit. As I haven't tried out other shells I couldn't say which one might be more suitable... It's tight with these but doable if done with care.

Best of luck anyway and fire away if you have any more questions!

[ignotus]

BTW, I've been following the thread I posted at the top, and I've been reading very good reviews of this 6-way driver, using the zobel circuit (which the seller actually took from that same thread). If I were to start again I'd probably give this a try, though it might be a challenge to fit it all in a universal shell.