[Xymordos]

 
OK, thanks for the update.
Is it possible that you've soldered one of the wire to the housing of the driver? some overlaying solder or litz touching the case? The problem here could be related to such issue on ED driver.

It doesn't appear so. But is the problem definitely due to the ED/DTEC drivers? Could a loose seal in one of the tubes cause this too?
 
The phase of the ED driver should be correct, since when you listen to it the center image is perfectly fine. In fact, listening to it you can't actually tell anything is wrong! I'm suspecting it is the DTEC driver...unless reversing the polarity doesn't actually affect the center image?

 

[tranhieu]

Try reversing the polarity of drivers on the side that's having problem one by one with the earpiece attached to the coupler thoughout the process and see how its response changes. 
 
If it doesn't work, check if tube length is the same on both sides. It's just phase cancelling, nothing major.

 

[Xymordos]

Thanks! Reversing the polarity on the DTEC resolved the issue...weird. It was wired correctly before!  

 

[CMOS1138]

I switched from green dampers to brown on my GQ build, I like the sound much better this way. There is still plenty of base but now the overall tone is brighter. Next up, GQ + DTEC.

 

[tomtomtom]

  Try reversing the polarity of drivers on the side that's having problem one by one with the earpiece attached to the coupler thoughout the process and see how its response changes. 
 
If it doesn't work, check if tube length is the same on both sides. It's just phase cancelling, nothing major.

How were you able to tell that it is phase cancelling? Just trying to understand in case I run into the same issue.

 

[tranhieu]

  How were you able to tell that it is phase cancelling? Just trying to understand in case I run into the same issue.

The sharp dip @ 1khz. If they were all in phase acoustically there would have been no such dips at all.

 

[piotrus-g]

  Thanks! Reversing the polarity on the DTEC resolved the issue...weird. It was wired correctly before!  

Great now you have to rework your crossover to fix the deep at ~3kHz - move ED crossing point to the lower frequencies or use it as full range.

 

[Xymordos]

I'll have to do that for the next one I make (should be before the end of the week). I had to fix this one too many times so the drivers and components were really weak already :\ Good practice though! 
 
Custom shells are really hard to use, since tube length takes forever to measure and adjust on each ear piece. Usually one ear piece comes out perfectly and the other one screws up...

 

[piotrus-g]

Custom shells are really hard to use, since tube length takes forever to measure and adjust on each ear piece. Usually one ear piece comes out perfectly and the other one screws up...

That's why customs are this expensive - it takes time to make.

 

[Xymordos]

Yup, once you try making one you realize how long and how much effort it takes to make one. Especially the testing part.

 

[tranhieu]

Time consuming as it is, you will get use to it later on. The process is very straight forward anyway. At the end of the day tuning is always the toughest part.

 

[wjp007]

Anyone try making a deep insertion custom shell, some of the companies call them Musician fit?  I'm looking for ways to improve isolation.  I've also seen silicone filled IEMs, anyone try that?  

 

[Mython]

  Anyone try making a deep insertion custom shell, some of the companies call them Musician fit?  I'm looking for ways to improve isolation.  I've also seen silicone filled IEMs, anyone try that?  

 
 
Some (fitear being one, I believe) even fill the CIEM shell with solid acrylic.
 
But that's not for the feint-hearted, since there's not much chance of extracting the components without damaging them, if you decide to destroy the CIEM shell.
 
And, of course, it's pretty-much a no-go if your BA's are of the vented type.

 

[Xymordos]

Last time with one case of phase cancelling you can fix it by reversing a driver. This time when I'm testing something new I got two phase cancelling at 4/5k and 10k. I tried reversing all drivers and the cancelling is still there. Could it be phase incoherent between all drivers?!

 

[MuZo2]

Can you post new measurement.