Do custom IEMs have to be hollow?

[thestevegraff]

Hello,
 
Long time lurker, first time poster.
 
I have a question about custom IEMs: I know that there are IEMs that are hollow shells, with drivers and electronics glued into place inside the shell after partial curing, but I wonder if that is necessary, and I haven't read anything either way here or on other IEM sites. So, is it possible to have an IEM that is solid, with the driver embedded in the acrylic or other material it's made of? I think it would be ok as long as the curing process didn't subject the driver or crossover components to damaging temperatures, or the driver wasn't deformed in the curing process.
 
I do have a custom IEM and I honestly can't tell if it's partially hollow or not. I do see seams in the material that would seem to indicate either hollowness or incremental pouring of resin, but I can't be positive. I guess the next step is to drill a tiny hole and find out. 

 
Thanks in advance.

 

[cravenz]

No, IEMs don't have to be hollow. I believe FitEar's CIEMs are filled in with acrylic. 

 

[Ivabign]

I imagine an acrylic CIEM that was completely filled would be hell to reshell - I can understand that some would like their drivers to be forever suspended in material - but I would imagine that any repair would likely destroy the BA drivers suspended in that material - so most companies don't - But they don't leave them bouncing around like a beans in a Maraca.

 There must be a happy medium between access and stability.

 

[darkdoorway]

Bit of a ghost thread..... I've felt for a while now that filling up ciems would help with isolation. A lot. Ciems are generally already very isolating, but I suspect with a filled ciem, you'd get to another dimension of isolation.