Hello everyone.
I learned a lot from this forum and made an IEM.
I am grateful to everyone who shared a lot of knowledge.
I'm not good at English, so I use google translate. I'm sorry if there is strange English.
I did a lot of experiments, tests, measurements and auditions to make an IEM.
The model version of the IEM is 12, and I'm finally proud of the IEM I like.
I made it as follows.
1) Create impressions.
2) 3D scan with iphone (Trnio).
3) Mold the 3D model with meshmixer.
4) Create a part to attach the face plate with FUSION 360 and convert it to STL.
5) Synthesize the impressions model and the face plate model with meshmixer.
6) Design the sound path part with FUSION 360 and subtract it from the external model.
7) Design the face plate with FUSION 360.
8) Print the model with a 3D printer (ELEGOO MARS 2 Pro).
9) Lacquer the printed material.
10) Adjust the network and damper while incorporating the unit and performing measurement (REW).
11) Make a face plate, cover the IEM and it's done!
model: IEM-012 is 10BA. All units are from langzhisheng (AliExpress).
EJ-30029 x 1 (≒ CI-22955 x 2) + Red Dumper (2200 ohm)
4.7uF + FWEK-31785 x 1 (≒ DWFK-31785 x 2) + Brown dumper (1000ohm) x 2
0.68uF + FWEK-31718 x 1 (≒ SWFK-31736 x 2)
I am using Rubycon PMLCAP for the capacitor. SMD type small film capacitor.
The sound is very clear. I have the illusion that my ears have improved. The treble (6kHz and above) is weak in the frequency response measurement, but it doesn't hurt because of that. I like the KZ ZAX and ZAS sounds, but the IEM-012 sounds better than them.
Since the impedance is low (10 ohm), a high-performance amplifier is required. A small amount of electrical noise becomes a sound. Also, the output impedance of the amplifier must be low enough. I am using the voltage follower circuit of THS4631.
The face plate can be replaced. I made different designs of faceplates using various techniques. I can exchange it depending on the mood of the day.
I have done a lot of experiments so I have gained experience and knowledge. I would like to share that experience with you.
Sunburst!
The Metal
Aurora
Racing
IEM-012 Frequency characteristic
IEM-012 Impedance characteristics
IEM-012 Sound path design
Inside IEM-012. I use a kneaded eraser.
Various IEMs(1DD+2BA,1DD+7BA,8BA,6BA etc...)
Replaceable face plate
Jigs and microphones for testing.