[Jedrula1]

If you hadn't explained this, I would've thought that this is a demonstration of a damper of some sorts (maybe not a proper damper which has an effect starting from 1K). My guess is that you end up with less volume of air in the purple scenario that actually does have this effect. Perhaps using a slightly larger combined tube would work, maybe a 2.2-2.5mm ID 10mm long tube (which would change peaks in the end and might be even worse).

My second guess is that your bass driver went from 20mm 1ID tube to 10mm 1ID + 20mm 2ID which is obviously more air meaning a stronger treble from this driver (less damping). Because it reduced treble frequencies, it looks like your drivers are out of phase meaning that the increased treble from this driver actually reduces treble being put out from the other driver. - This is a wild guess and there is no way for me to know the kind of crossover and driver configuration you are using.

Someone please educate me if anything I've said isn't logical, I am just trying to help with pretty limited knowledge. Also @Jedrula1 , keep updating us - especially what ended up being the real reason that was causing this.

The drivers and crossover looks like:

-Sonion 3800 (connected in series) with lo pass 110ohm resistor in series and 10uF capacitor in parallel, 3300 ohm damper inside 1ID 20mm tube
-1723 Sonion Accupass module, 2ID no damper 20mm tube:
- Sonion 1700 with 20 ohm resistor in series
- Sonion 2300 with 10uF capacitor in series conected in reversed phase

The FR os each driver with two separate tubes (Pink is 3800, green is 1700, yellow is 2300 and blue is a complete FR.

EDIT: So there is not too much chance to have phase issues between 3800 and 2300. There are not in phase, but the roll of of 3800 starts at 300hz.

 

[vladstef]

The drivers and crossover looks like:

-Sonion 3800 (connected in series) with lo pass 110ohm resistor in series and 10uF capacitor in parallel, 3300 ohm damper inside 1ID 20mm tube
-1723 Sonion Accupass module, 2ID no damper 20mm tube:
- Sonion 1700 with 20 ohm resistor in series
- Sonion 2300 with 10uF capacitor in series conected in reversed phase

The FR os each driver with two separate tubes (Pink is 3800, green is 1700, yellow is 2300 and blue is a complete FR.

EDIT: So there is not too much chance to have phase issues between 3800 and 2300. There are not in phase, but the roll of of 3800 starts at 300hz.

This is quite weird because the treble got quite a bit reduced once you've changed tubing. There is a pretty consistent drop in treble in 4.5 - 11K region of around 4-5dB and a new dip @8K. This 8K might be an anomaly where 3800 driver creates a really strong peak in this region due to a horn like effect introduced by increasing the tubing size - I've seen this happening a couple of times, just not with this kind of crossover + damper combination. The consistent drop in treble is probably due to 2300 losing energy, are you sure that nothing is blocking the tubing?

Ultimately, you will probably have to meassure individual drivers with new tubing which will be painful but might be worth it as it will save you the time.

 

[Jedrula1]

Ultimately, you will probably have to meassure individual drivers with new tubing which will be painful but might be worth it as it will save you the time.

Vladstef, That is exactly what i am going to do tomorrow. Nice remarks by the way I will measure each driver individually with new, 2ID tubing - maybe this will give an answer where the problem is. I will post FR curves here as soon as possible

 

[Jedrula1]

Alright, got measurements. Each driver separate and all together.This is how the tubing looks like:

And here are FR curves:

So, the phase is not the problem - i think. The 2300 FR curve alone has the same issue - lower level between 2k and 8k, So the issue probably is in the tubing. But... why? The ID before and after in combined tube is the same (2ID).

 

[vladstef]

Alright, got measurements. Each driver separate and all together.This is how the tubing looks like:

And here are FR curves:

So, the phase is not the problem - i think. The 2300 FR curve alone has the same issue - lower level between 2k and 8k, So the issue probably is in the tubing. But... why? The ID before and after in combined tube is the same (2ID).

Very cool measurements and overall build. So now you know for sure that something is acting as a damper - it could be some glue inside tubing which I doubt. The more apprent thing would be that the short tube from 1723 is not really a 2ID tube because the tube might have reduced or elongated shape where it is pressured to fit inside the other 2ID tube. Small changes in shape can be more drastic than it looks.

Here is an idea that I had for a while now for my build (I've seen this done in a similar shape just more complex with more branches, I think it's one of Unique Melody IEMs). Tubing done in a form of tree branches, something like this:


You'd have a 15mm 2ID tube with a small hole on one side where you'd glue in the 10mm 1ID tube from 3800. I can't guarantee that it will fix your problem and it's probably not easy to do, but it would give your treble driver a completely unobstructed path. Having said this, you could probably modify your existing tubing to clear up the path a bit.

 

[Jedrula1]

Here is an idea that I had for a while now for my build (I've seen this done in a similar shape just more complex with more branches, I think it's one of Unique Melody IEMs). Tubing done in a form of tree branches, something like this:

Cool idea! How to make this connection permanent and reliable?

 

[vladstef]

Cool idea! How to make this connection permanent and reliable?

The only thing that comes to mind is making the surface of tubes very rough near the connection and using ample amounts of uv glue in a few layers. This could work in theory but I've yet to try it. Cutting the 1ID tube at an angle and then perfectly replicating it on the other side as well as making sure that no glue gets inside the tubes while creating a perfect seal - almost sounds impossible.

Maybe fully penetrate the 2ID tube with a 1ID tube, glue it and then remove the unwanted remains of the 1ID tube inside the 2ID. I've no idea how I'd do the second part of this.

This is professionally done by using some sort of injection moulding on a micro scale which is extremely expensive even for mass production compared to regular tubing, but it makes assembly easy and fast.

 

[Lucas Taboada]

I'm having trouble to cure this part of my shells:



I'm curing for around 32s in a LED chamber that I've made:



If I let for 40-45s it cures a thin layer, and my walls gets too thick, some parts around 4-5mm.

Anyone know what it could be? Bad transparency in my negative mold maybe? Here's both materials that I've tried:

Gelatin:


Hydrocolloid/Agar from a company that sells for Hearing Aid labs here in my country:

 

[alanwcruz]

I'm having trouble to cure this part of my shells:



I'm curing for around 32s in a LED chamber that I've made:



If I let for 40-45s it cures a thin layer, and my walls gets too thick, some parts around 4-5mm.

Anyone know what it could be? Bad transparency in my negative mold maybe? Here's both materials that I've tried:

Gelatin:


Hydrocolloid/Agar from a company that sells for Hearing Aid labs here in my country:

That used to happen to me too, now I do the following, I got a nail curing light with florescent bulbs, these bulbs cure much slower than LED's, so I place my gelatin mold on the bulb and cure for 30 seconds, then I place my led chamber on top of the bulb covering the sides of my mold and cure for another 20-30 seconds. So in total I get some 50-60 seconds of bottom up light from the bulb and 20-30 seconds of LED light from the sides.

Placing a mirror under your mold also helps if you can't get florescent bulbs.

 

[Jedrula1]

The only thing that comes to mind is making the surface of tubes very rough near the connection and using ample amounts of uv glue in a few layers. This could work in theory but I've yet to try it. Cutting the 1ID tube at an angle and then perfectly replicating it on the other side as well as making sure that no glue gets inside the tubes while creating a perfect seal - almost sounds impossible.

Maybe fully penetrate the 2ID tube with a 1ID tube, glue it and then remove the unwanted remains of the 1ID tube inside the 2ID. I've no idea how I'd do the second part of this.

This is professionally done by using some sort of injection moulding on a micro scale which is extremely expensive even for mass production compared to regular tubing, but it makes assembly easy and fast.

Doesn't seem to be reliable... But... gonna try and share results here!

 

[jbr1971]

I'm having trouble to cure this part of my shells......

I had that problem with the first couple sets I made. I placed a mirror flat on the table, then put my uv nail lamp on top so light would get reflected back up to that underside area. Worked great after that.

 

[JoyjeetPanday]

Hi, I am an audio dude from India and have just started digging down this rabbit hole and I just stumbled upon this website and the thread 2 days back.
So I made some custom sleeves for Shure SE series IEMs much like Sensaphonics.
Lately, I took a set of measurements using a DIY apparatus comprising of :

Test Subject ( Shure SE 425 + Comply Foam/ DIY Sleeves/ Sensaphonics Sleeves ) -> Silicone Tubing -> Beyerdynamic MM-1 -> RME BabyfacePro -> Smaart.

Trace Color Coding:
Pink - Shure SE 425 + Stock Comply Foam
Black - Shure SE 425 + Sensaphonics Sleeves
Blue - Shure SE 425 + DIY Sleeves

Solely judging by the data:
1. The coherence is insane and there's zero smoothing in either of the phase trace or FR plot. Am I measuring them too close such that I am only measuring the driver response?
2. The phase trace goes haywire beyond 7-8k. Starts taking place from 7k. Which again is being explained from the FR plot that there isn't enough data. Although while listening to them I can hear things beyond that zone but according to the measurement there isn't any significant data even-though the coherence is full. Is everything beyond 10k being absorbed by sleeves or anything in the measurement apparatus? Then again the SE 425s with comply foam are following the same trend. What am I doing wrong?
3. Is the data being affected by affected by the different attachments or am I nullifying them during measurement in someway?
4. Is there anyway to get colour options for soft shell mold? I am using Egger Flex A/B 40 Shore.

This thread is like the Bible for DIY IEMs and I'm lucky to have found this. This is my first post in the forum and I'd like to thank everyone who have contributed over the years in making such a comprehensive and vast amount of information.
Looking forward to a good start in an amazing community. Much love.

 

[michal1315]

Hi. I'm want to make my second diy iem and I'm need some advice. My first iem are based on ED29689 with red filter and for my taste it will by to much mid centric with lacking of bass and not as clean treble as I'm expected. In my second iem I'm want to use HE-31751 or GQ-30783 driver with universal shell and about them I'm have a few question.

1. How looks sound signature of HE-31751 is it as mid centric as driver in ER4P, I know that bass will be much better but peak at 2,5k scares me a little?
2. I'm want use HE driver with one sound tube,can it be possible with good results?
3. How HE will be work on mobile device like a smartphone with his 112 ohms impedance, my device is Xiaomi Mi6 with WCD9335 audio ic which has output 62.5mW at 16ohms?
4. How GQ sound compared to HE?

Thanks.

 

[vladstef]

@Jedrula1 , so I've been doing some research about your problem (and potentially mine in the future). There are all kinds of tube connectors, medical grade and aquarium grade, that could potentially with minimal modifications solve your problem. I have yet to find the perfect one, but here is what I googled and the connectors that could potentially work. I've tried - vynil/silicone/pvc/flexible tubing connector/fittings. All kinds of connectors will pop up, many of which are even smaller than what we need.

Here are some examples:

Spoiler

Number 4, 5, 6 is the type of connector that could work - would just need to cut the ribbed parts to reduce the size of connector. Finding the 2mm ID one might be problematic.


This type works with OD of tubes, this specific one is for 2.5mm OD tubes which is way to small for 2mm ID tubes.

 

[cjxj]

Got a problem to solve. I have to make an ciem with very small ear canal - so small that it is impossible to have two soundbores. I have to connect one 1ID and one 2ID tube earlier into one 2ID tube. The total lengths are the same - why the freq responce is so different between 5khz and 8khz? The blue graph shows two separate soundbores (2ID 15mm long, 1ID 20mm long). The purple graph was measured with a usage of adapter (2ID 5mm long and 1ID 10mm long into 2ID 10mm long) - so the total length is the same. Have no idea what causes such a cavity in mid-high area. Any suggestions ?

I recently made a set of CIEMs for someone with a very small canal. I was able to use some very thin walled stainless capillary tube from EBAY. Used 1mm id for dual bass drivers and 1.5mm id for the TWFK mid/high. Only had to use if for the last 1/2 inch or so. Tedious but worked out well.