Home-Made IEMs - Page 88

Originally Posted by piotrus-g 

Hmm I listened to XBA3 for a few minus and I liked the sound. I listened it from clip+ though from Samsung galaxy S it sounded very lacking

They are sensitive to output impedance which I tested.  They sound okay and some user preferences will like their new sound, however they're not free from faults, such as phase shift which you mentioned once before.  If you value laser-like precision and natural tones, they sound like VHS tape.  Still, if you've never heard an IEM before or you can get "into their zone", then they sound ok.

A silicone product called Silcoval MVE. It makes a good mould, but Its mixing ratio of adding 2% hardener is really tough to get right. So I'd suggest getting some easier silicone to work with.

Quote:

Originally Posted by NuckinFutz 


When I was looking into this a silicone mould made more sense to me, gotta be more comfortable! Are they a hollow shell, if so is this hard to do with silicone?

Oh, I thought you meant the negative mould material, which is this:

The shell i made from an epoxy called cold glaze. First I made a solid shell and hollowed it out with a dremel. Subsequent shells I cast hollow by using a "plug" made from a hot glue impression from the first shell. Like this:

Maybe the same method could be used  for casting hollow silicone shell as well. The problem would be sealing the shells afterward, as virtually nothing sticks to silicone, except maybe other silicone. You could try casting the shell with the drivers inside, if using silicone. Even though my epoxy shells are a hard material, I find them quite comfortable. I was positively surprised.

What did you make that casting mold from? I have now tried 2 things that did not work. Candle wax, and a pourable latex called  "mold builder." both ended up pulling away from the impression. the the latex mold builder was not it says you're supposed to paint on the mold one layer at a time until it gets built out.

Quote:

Originally Posted by wz2000 

 

Oh, I thought you meant the negative mould material, which is this:

 

 

 

Originally Posted by tony-pro 

What did you make that casting mold from?

 

The answer is just few post above.

Quote:

Originally Posted by wz2000 

A silicone product called Silcoval MVE. It makes a good mould, but Its mixing ratio of adding 2% hardener is really tough to get right. So I'd suggest getting some easier silicone to work with.

judging from the materials that has been used across this thread someone's going to get hurt finally. Don't use materials that are not compatibile with ISO 10993.

I know that making your own IEMs is tempting but remeber - safety first.

Quote:

Originally Posted by NuckinFutz 


Great, thanks for the info!
I did see a video on Youtube of how UE or Westone (can't remember which) make their customs and they mentioned a mixed casting with Silicone tips and acrylic body.....essentially best of both worlds. I was thinking just casting them solid with the drivers in place would be ideal but difficult...and a pain in the butt if it goes wrong!

If you cast the shells from silicone, it shouldn't be too hard to cut them open if something goes wrong. Not so with epoxy or acrylic.

Quote:

Originally Posted by piotrus-g 

judging from the materials that has been used across this thread someone's going to get hurt finally. Don't use materials that are not compatibile with ISO 10993.

 

I know that making your own IEMs is tempting but remeber - safety first.

Most of these casting and mould materials are toxic when still uncured(especially the hardeners), but should be chemically inert once fully cured. Doesn't hurt to be careful though.

I am looking for a crossover design for my next project.

The drivers will be:

one CI-22955 and one ED-29689.

Since the famous Etymotic ER-4s is using a single ED-29680 and the reviews are great,

I am thinking on adding a CI-22955 to compensate the known lack of bass.

Sugestions for the crossover and the filters are welcome!

Quote:

Originally Posted by kiteki 

I don't think the Sony XBA's have acoustic dampers, they diaphragm is specifically tuned to a different frequency in each driver.  Either way, they don't suffice, I can't listen to the XBA-3 or XBA-4 for more than 30 minutes, I can't stand them.

I don't see whats wrong with acoustic dampers. Ultimate Ears use them in almost all, if not all their custom IEMs to shape the sound. Other custom IEMs just have a capacitor or resistor just for the sake of having a "passive crossover" for marketing as well.

Overlapping frequencies doesn't seem like a desirable feature, and the Sony XBA has very hazy imaging / layering compared to a precision IEM like the UE700 or CK10, IME.

Quote:

Originally Posted by LaaG 

 

I don't see whats wrong with acoustic dampers. Ultimate Ears use them in almost all, if not all their custom IEMs to shape the sound. Other custom IEMs just have a capacitor or resistor just for the sake of having a "passive crossover" for marketing as well.

just like acoustic waveguides with speakers, they really arent enough all on their own. they are good for keeping the passive components in the XO to a minimum, but they cannot replace the XO entirely. for starters if the tweeter is sent the full signal including bass that is out of its operating range, you will kill the tweeter. there is nothing wrong with using them as a tool, but they simply cannot do the full job in a multidriver IEM, they can be used to filter the output frequencies, but they cannot filter the distortion and or damage caused by sending them audio and power outside of their SOA

Quote:

Originally Posted by wz2000 

 

Oh, I thought you meant the negative mould material, which is this:

 

 

 

 

The shell i made from an epoxy called cold glaze. First I made a solid shell and hollowed it out with a dremel. Subsequent shells I cast hollow by using a "plug" made from a hot glue impression from the first shell. Like this:

 

 

 

 

Maybe the same method could be used  for casting hollow silicone shell as well. The problem would be sealing the shells afterward, as virtually nothing sticks to silicone, except maybe other silicone. You could try casting the shell with the drivers inside, if using silicone. Even though my epoxy shells are a hard material, I find them quite comfortable. I was positively surprised.

some people are allergic to epoxy and it generally isnt considered safe to use internally