Home-Made IEMs
Jun 17, 2014 at 9:18 AM Post #1,816 of 16,075
  Where is the nozle on shell? Is there enough space for crossover components?  Also you can skip the tubing and integrate them into shell , just the Westone4 or shure iems.

Here you go, the latest iteration of my design.
 
I tested it out with a 0.75mm wall thickness and it's nice and transparent!
 
The no tubing idea was already in the works, and you can note the "boot" fitting into a smaller notch, and the drivers held in place inside. The CI is offset about 3mm behind the WBFKs and 2mm behind the DTECs so I can push a red filter in there if I want.
 
I'm using tiny tiny resistors/capacitors (1206 SMD) size which are about 3mm long, so no worries about fitting a whole crossover network inside if i want to. There's plenty of space behind the WBFK on the opposite side.
 
I need to ask, what happens if the metal cases of the drivers are in direct contact? There's no electrical interference/grounding going on right? Also, what diameter nozzle should I choose? I'm currently using a 3mm nozzle with 1mm inner diameter for extra strength. Which is most compatible with shure olives?
 
I'll try to get some photos of the semi completed IEMs tomorrow when I print this copy.

 
Jun 17, 2014 at 4:03 PM Post #1,818 of 16,075
That's some really nice work there dude!
I envy your CAD skills.
 
Have you seen the new connector/cable offered by Linum?
It might be worth looking at for a couple of reasons:
 
1.It's smaller, and may give you a tiny bit more room, or a smaller 'hood' to house the connector, or more material round the connector for strength.
 
2.Linum's claims for the mechanical performance/robustness are truly exceptional compared to existing connectors.
 
Oh, and since it's so tiny, it looks great, almost like a fixed cable! ( exactly like a fixed cable when the socket is recessed )
 
I don't mean to suggest that there's anything wrong with your design as is though!
I'm just 'that guy' who can't help flapping his gums about how he'd improve that lilly if only he had access to some gilding facilities 
biggrin.gif

 
Well done!
Looking forward to seeing your posts on the rest of the process.
 
Jun 17, 2014 at 9:03 PM Post #1,820 of 16,075
   
Quote:
  That's some really nice work there dude!
I envy your CAD skills.
 
Have you seen the new connector/cable offered by Linum?
It might be worth looking at for a couple of reasons:
 
1.It's smaller, and may give you a tiny bit more room, or a smaller 'hood' to house the connector, or more material round the connector for strength.
 
2.Linum's claims for the mechanical performance/robustness are truly exceptional compared to existing connectors.
 
Oh, and since it's so tiny, it looks great, almost like a fixed cable! ( exactly like a fixed cable when the socket is recessed )
 
I don't mean to suggest that there's anything wrong with your design as is though!
I'm just 'that guy' who can't help flapping his gums about how he'd improve that lilly if only he had access to some gilding facilities 
biggrin.gif

 
Well done!
Looking forward to seeing your posts on the rest of the process.

I'm an engineering student hence such skills are hard not to come by :).
 
While that Linum connector looks great, I've already purchased a local made cable for mmcx connector. After this project, if I decide to go down the custom IEM route I might consider upgrading again!
 
I wanted to standardize on an easy to find cable which is why I chose the MMCX style connector even if it's slightly large. I'm sure you're agree that my shells are already quite small compared to the commercial ones, especially for a CI/DTEC/WBFK combo.
 
Certainly I'm happy to take onboard all suggestions as this is my first time making IEMs, and I'm happy that this community exists! Please keep up the feedback :).
 
MuZo, will having a 1mm inner diameter for the nozzle impact the sound greatly? I'm more concerned about the nozzle breaking off, which is why I've set a 1mm thickness for the walls.
 
Does anyone know what is the maximum outer diameter of nozzle that will fit shure olives well?
 
My first round of printing. Note some imperfections (not glossy) on the underside of the right-most nozzle which might cause it to fail, plus some broken supports (increased size already) but the size and fit are roughly correct! I'm currently doing another run, this time with the boot to fit drivers in!
 

 
Jun 18, 2014 at 12:03 AM Post #1,822 of 16,075
   
Generally, BA mounting is done with a type of UV-cured acrylic.
 
I suppose epoxy resin might be viable, though.
 
I would avoid using superglue, if possible, because of the fumes it gives-off, which may, potentially, cause damage to components.
 
Superglue fumes are even used in forensics, for the purpose of 'fixing' invisible fingerprints - cyanoacrylate fumes should not be underestimated and although some may disagree with me, I would personally never use superglue anywhere near balanced armatures; not for fixing them in place, nor for affixing tubing to the BA nozzles.

How about mounting of the tubes? Would you recommend the same UV curing acrylic?
 
Jun 19, 2014 at 11:30 AM Post #1,826 of 16,075
I saw that Knowles announced new drivers that are more efficient: HODVTEC and SWFK. Anyone know when will they be out?
 
Jun 19, 2014 at 11:40 AM Post #1,828 of 16,075
Sadly, I have killed one of my WBFKs in testing when I managed to rip off the solder pad and break the wires underneath, most likely due to excessive flexing.
 
I'll keep testing with the other one, and order whatever I break/need after I'm done because of the $30 shipping cost unless I have an order more than $135 :frowning2:.
 
Lesson learnt, make sure wires have stress relief, especially when testing.
 
Also. I have this bad feeling that the CI and DTEC combo is too strong in the bass when combined. CI is overwhelmingly loud and muddies up the mid range if unfiltered.
 
Using a 2nd order 100uF/4ohm lowpass (x2) I managed to tame down the CI till it's just a thumping at the bottom frequency range.
 
Just having the bandpass filter in place seems to affect the DTEC frequency response, which is puzzling since I thought having the DTEC unfiltered should give the same response. Is there some interactions between the filter and driver that I'm not considering?
 
On the other hand, having the filtered CI, unfiltered DTEC and a 0.1uF cap on the WBFK seems to yield a reasonable sound.
 
Jun 19, 2014 at 3:03 PM Post #1,829 of 16,075
But they're not for retail sale anywhere?
 
I was planning to make one with the typical CI as lows, ED29689 as Mids and another ED29689 as highs. I only want to use a high frequency cross over and try to use other things to tune the bottom and the mids. Wonder if it'll work. Are the frequency outputs of the two drivers around the same loudness? CI seems to give off 120db of bass on the graphs while ED only gives 100db of mid/high. 
 
Jun 19, 2014 at 3:25 PM Post #1,830 of 16,075
which drivers? if you are talking about the hodvtec, it only has one sound port. if you are talking hodvtec and swfk, no they are not the same but really no diff than using an ed and ci. You just gotta get your xover system right
 

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