[threedprof]

Hey everyone. I've been lurking around for several years trying to get my head wrapped around the immense brain-dump of information. So, let's just say this project was spawned thanks to this forum.

Parts used:
Knowles GV 32380 bundles
1500A Tweeters @ 5mm from the end of the snout and useing #16 NEAL tube with #13 bushing.
2200A mids/subs @ 7mm from the end of the snout and using #13 NEAL tube with a tiny piece of #16 to hold onto the snout.

Now time for the pics.

It all started with the ear impressions


Since I didn't really know what i needed from the audiologist, he trimmed way too much off but then it was too late to go back and get them redone. So I improvised with a clay buildup


First shell didn't turn out so great. Won't bore you with the details of the other few failed shells BUT valuable lessons were learned during this process. I learned that I could simply add UV resin to certain areas and basically "Sculpt" the final product.


Once I was happy with the design, the Knox Gelatin/Vegetable Glycerin mold making process could begin


After seeing so many of you seal your IEMs in (likely because you all know what you're doing) I opt'ed to keep mine hollow and parts accessible. Here is the lid created with the bolt/nut standoff molded into place. Fastened together with micro stainless steel cap screws/nuts. Worked out first whack!





Since i didn't have the cable yet, I may have to excavate the MMCX sockets and remake the lids. We'll see once it arrives from china.

Thanks for taking a peek at the build. Feel free to comment and let me know if there's something glaringly incorrect.

 

[threedprof]

Yay! cable arrived from china after a couple of weeks being stuck in customs..boooo. The detail of the hi resolution tracks blow me away, when A/B'ing them against my standard earbuds they're excellent! My only real issue is the bass seems to be fairly anemic. Is this a known trait of the GV-32380 bundle? if so, what's a good solution to put some punch and bass into these customs? using a Galaxy S7 (soon to get the LG V30 when it hits the streets)

 

[threedprof]

Final product

 

[chef8489]

OK so you are not using a crossover? How are you testing to see if each driver is actually working and not just one? How ate you making sure they are using proper frequency seperation per driver? Have you ever listened to proper multi driver iems?

 

[threedprof]

Thank you for the reply, Chef.

To answer your questions, my testing was very rudimentary. Because of the two piece shell, I was able to experiment with a few damper values and pre-setup tubes. I made sure they all had sound coming from each bank of speakers by blocking each tube and listening.

From there, I read the knowles GV-32380 bundle has a crossover built in so I took it on blind trust that it would all just work. So far, these are the only multiple driver headphones I've ever tried. Since i have no clue about the science of audio i had to rely heavily on the deep information of this forum, Youtube, and articles on what makes for a great listening experience.

Outside of that, I'd like to try making other sets and experimenting with driver combinations or even a hybrid set. I'm all ears if you have any advice for a super novice

 

[chef8489]

Truthfully my advice would have been have experienced ear with different iems as and headphones before attempting this. Knowing what a propper sealing iem, custom iem, and multi ciem sounds like as you really dont. You are just guessing at if you have a propper seal or if the drivers sound correct.

Now thats out of the way. Lets say if you are getting a perfect seal and both drivers are working perfectly. Only way to get more low end is add a second low driver and a custom two way crossover or a larger double low driver and a three way crossover.

 

[threedprof]

Yeah that sounds great! unfortunately, I don't have the luxury of testing IEMs nor the funds to invest in buying highend CIEMs. This is as good as it gets for me.

As for seal, I'm experimenting with hollowed memory foam earplugs surrounding the snout. Seems to help tremendously but its very uncomfortable. So back to finding a suitable material. I might try fusing a very soft silicone layer around the snout.

I did make sure the speakers are in-phase, though. I could here the difference, as descibed by others on what it would sound like. It'd be awesome to have some proper testing equipment

 

[chef8489]

YOu can add more uv acrylic a thin layer at a time to build it up till you get a good seal. Should be a good 26db sound reduction. Like good earplugs or like being underwater if that makes sense.

 

[threedprof]

Now thats out of the way. Lets say if you are getting a perfect seal and both drivers are working perfectly. Only way to get more low end is add a second low driver and a custom two way crossover or a larger double low driver and a three way crossover.

Ok cool. According to the specs of the GV-32380, the lowest it goes is 70hz. What would you recommend as a subwoofer to pair with it? Or should i try redesigning the shell to accomodate a dynamic driver?

 

[chef8489]

Not a dynamic. I would choose a dynamic that went down to 5hz. Probably one like westone or ultimate ears uses that is a double. Depends how much bass you want. A singgeissele le will make it fairly balanced while the double will make it hit hard and a bit warm.