Home-Made IEMs
Jul 24, 2021 at 11:59 PM Post #13,082 of 14,363

Wgibson

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I would try venting the CI and use something between 0.2 and 0.6mm ID.

This sonion 20x53 is big, like a CI but has some internal damper already so it has good rolloff by itself, smaller tube helps even more.

Check out these two graphs, I assume venting the CI would have similar results as the 20x53. Vented CI with small diameter tube should give you a good rising slope down to 25hz or so if I were to guess.


Sonion 20x53 vented test.jpg

CI-30120 brass tube.jpg
 
Jul 25, 2021 at 8:11 AM Post #13,084 of 14,363

musmecca

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I would try venting the CI and use something between 0.2 and 0.6mm ID.

This sonion 20x53 is big, like a CI but has some internal damper already so it has good rolloff by itself, smaller tube helps even more.

Check out these two graphs, I assume venting the CI would have similar results as the 20x53. Vented CI with small diameter tube should give you a good rising slope down to 25hz or so if I were to guess.


Sonion 20x53 vented test.jpg

CI-30120 brass tube.jpg
Thanks! That was the graphs I remember seeing and I thought the analysis was solid. I went with the 1mm diameter as it was readily available and I recall you hinting at decreased marginal returns on tubes smaller than 1MM....i.e. didn't really add much to the game below 1MM. Was i wrong in that assumption? I have not tried venting a CI in this application.....I may try that on my next retrofit.
 
Jul 25, 2021 at 10:34 AM Post #13,085 of 14,363

mattmatt

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Looking at your sound bores... Instead of extruding parts then creating pipe then creating lofts between pipe and extrudes. Do the extrudes then open sketch, select 3D sketch and do multi point spline - start by snapping end points to extruded profiles then add few more spline points, then go to loft - select profiles of the extrudes and add rails - select spline (for some lofts you might need two splines for perfect loft), adjust computing options to achieve smoother transitions. The effect is smooth single line that you can later easily adjust by moving splines on the sketch.
Holy crap, game changer! Thanks for this. Definitely a game changer. Making some plugs for my girlfriend right now and wanted to play with it before printing. Tho this is imported to meshmixer for better viewing! :D
1627223574382.png
 
Jul 25, 2021 at 12:12 PM Post #13,086 of 14,363

dhruvmeena96

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I would try venting the CI and use something between 0.2 and 0.6mm ID.

This sonion 20x53 is big, like a CI but has some internal damper already so it has good rolloff by itself, smaller tube helps even more.

Check out these two graphs, I assume venting the CI would have similar results as the 20x53. Vented CI with small diameter tube should give you a good rising slope down to 25hz or so if I were to guess.


Sonion 20x53 vented test.jpg

CI-30120 brass tube.jpg
i guess its the CI with vent(sonion 20x53) or i maybe wrong, but there is a CI like driver with back vent in sonion catalouge which does take bass gods DD down to its knees
 
Jul 25, 2021 at 2:33 PM Post #13,088 of 14,363

Wgibson

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Thanks! That was the graphs I remember seeing and I thought the analysis was solid. I went with the 1mm diameter as it was readily available and I recall you hinting at decreased marginal returns on tubes smaller than 1MM....i.e. didn't really add much to the game below 1MM. Was i wrong in that assumption? I have not tried venting a CI in this application.....I may try that on my next retrofit.

I'd say 0.4mm ID is a realistic minimum, or use a short piece of 0.2mm inserted at the end kind of like a filter, but just using 0.2mm tube with any appreciable length starts to have db loss even at 20hz.

(Edit: haven't made a hybrid yet so if you couldn't tell, I'm very interested in getting BAs to do sub bass.)
 
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Jul 26, 2021 at 10:23 AM Post #13,089 of 14,363

swtnate

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First post but MAN, this has been an INVALUABLE resource. Ohhhhh, the amount of learning and investment to learning this industry. Im all in! From lab equipment, to drivers, and beyond. So, I thought Id pay a little bit of it back. Theres been many posts about hydrocolloid. One thing that I love about is how replaceable it is. One thing I hate about it is how EXPENSIVE it can be. 6kg of Egger is over $200 and Krystalloid is a bit better but not as forgiving and the dreve lacks tinsel strength upon impression removal. Ive gone through countless hours figuring this out and gave up no less than 5 times. Until, I read the Krystalloid MSDS. While this doesnt give the recipe, upon further reading on the effects Agar reacting with ethylene glycol, I had another starting point. I finally recreated, in my opinion, an improved Krystalloid. This is still reversable. All the items can be purchased from Amazon or from a chemistry supply house. One thing is imperative to have, and that is a reliable food/ gram scale.

this is the recipe for a 500g batch.
125g - propylene gycol
125g- ethylene glycol
15g - vegetable glycerine
5g - Agar Agar Powder (NOT THE FLAKES)
1g - Borax (not essential but seems to help with mold strength)
230g - filtered water

1) mix all the liquids together at room temperature.
2) add the Agar Agar. Using a whisk, stir in the Agar to the mixture. Let soak in solution for minimum of ten minutes. I like to use a stand-up mixer during the entirety of the soak time. HOWEVER, BE CAREFUL! ETHYLENE GLYCOL IS WHAT MAKES ANTI-FREEZE AND SHOULD NOT EVER BE INGESTED. Clean-up well with dish soap and water. I wash everything 3 times. Lol.
3) pour solution into a small cooking pot. Set the cooking temperature to LOW or 1. Allow to come to temperature. Stirring often.
4) increase cooking temperature to MEDIUM. Monitor temperature very closely with an infrared thermometer. Solution should NEVER come to a boil. Continue stirring as often as possible. The agar is not into solution YET. The mixture should be very cloudy when you stir.
5) This process can take up to 20-30 minutes, if not longer. Once you are able to stir the mixture and the cloudiness doesnt reappear then the agar has been absorbed into solution. Leave on stable heat (90-95°C) for an additional 15 minutes.
6. Pour i to separate container and allow to cool at room temperature. You will notice that it will stay rather thinly viscous even at lower temperature. Once it is at about room temperature, place into the refrigerator for one hour. Then you are ready to GO!

FOR REHEATING:
1) Cut/ chop the solidfied agar into small squares. The finer the chop the easier it will melt. Place into a small glass bowl that is microwave safe.
2) heat in the microwave for 2 minutes at 10-20% power. Monitor through the window during the melting process.
3) once complete, stirr the colloid slowly for 30 seconds to evenly dosperse the hotter and cooler liquids in the mixture. Allow the rest a total of 90 seconds while stirring. Repeat steps 2-3 until mixture is completely liquified and there are no lumps.
Optional: after the melting process is complete, I dont stir the solution. My microwave has a “warm and hold” setting. I press the warm and hold button and allow it to warm/ equalize for 5-10 minutes, depending on the amount of colloid. Also, if you go TOO long a film/skin will form on the top of the colloid (kinda like queso). You can easily remove it with a large spoon.
4) let cool to 115F and then slowly pour with the stream no wider than a pencil and the container as close to the investment form as possible.

this recipe is a little thinner than most (almost Dreve fotogel viscosity but WAY thinner than the nicefit). Small bubbles will NORMALLY escape no problem. I use a chemistry plastic disposable pipette to remove large bubbles.
UPDATE:
1) This formulation will not cause bacteria growth and mold like some agar recipes. So, it is VERY stable
2) This formulation wheeps (the watery discharge from all colloid negative molds) WAAAAY less than all the colloids I've purchased. Aside from the niceFit. However, the Nicefit formulation is SUPER thick and VERY difficult to evacuate air if you slightly over-heat the mixture.
3) I'm on my 5th reuse. So, you can continually re-use this stuff. HOWEVER, if you accidentally boil it its just as non-forgiving as the other colloids.
4) The first 2 molds created from the virgin mixture were the absolute clearest and cleanest colloid I've ever used. Not to be taken as a brag. It just shows the value in using FRESH products.
5) Don't try melt out more than 2 molds worth of colloid in the microwave. There's no way to uniformly distribute heat throughout the whole mixture. I CONSTANTLY get over-heated material if I try to do too much at one time.

In closing, this recipe is REALLY quite strong. It performs identically to other market level colloids at a quarter or less of the price. Just in case you were wondering, be careful when experimenting, to not add TOO much agar. If you increase the agar you will also increase opacity and the colloid becomes to crumbly. Food for thought. Never though I would ever post a review of my recipe. lol. But, here we are. HAPPY BUILDING!!
 
Jul 26, 2021 at 10:39 AM Post #13,090 of 14,363

kkugel

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UPDATE:
1) This formulation will not cause bacteria growth and mold like some agar recipes. So, it is VERY stable
2) This formulation wheeps (the watery discharge from all colloid negative molds) WAAAAY less than all the colloids I've purchased. Aside from the niceFit. However, the Nicefit formulation is SUPER thick and VERY difficult to evacuate air if you slightly over-heat the mixture.
3) I'm on my 5th reuse. So, you can continually re-use this stuff. HOWEVER, if you accidentally boil it its just as non-forgiving as the other colloids.
4) The first 2 molds created from the virgin mixture were the absolute clearest and cleanest colloid I've ever used. Not to be taken as a brag. It just shows the value in using FRESH products.
5) Don't try melt out more than 2 molds worth of colloid in the microwave. There's no way to uniformly distribute heat throughout the whole mixture. I CONSTANTLY get over-heated material if I try to do too much at one time.

In closing, this recipe is REALLY quite strong. It performs identically to other market level colloids at a quarter or less of the price. Just in case you were wondering, be careful when experimenting, to not add TOO much agar. If you increase the agar you will also increase opacity and the colloid becomes to crumbly. Food for thought. Never though I would ever post a review of my recipe. lol. But, here we are. HAPPY BUILDING!!
Very valuable post, thank you!
 
Jul 26, 2021 at 10:59 AM Post #13,091 of 14,363

Jerry-S

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Wow! Thanks everyone for all the helpful responses.
The reason I had decided on using DD or 38D1XJ was because I really don't want it to interfere with the rest of the tonal balance.
Just a subbass boost.
I know that the 38D1XJ is the best in the game atm. My only real concern with using it would be its significant SPL output and that may be too much and drown everything else out.
Seems like there has been a lot more experimentation with the Cl and that may be a safer option as I don't have a measurement rig so fine tuning will be difficult and pretty much done by ear.
 
Jul 26, 2021 at 11:24 AM Post #13,092 of 14,363

kkugel

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Wow! Thanks everyone for all the helpful responses.
The reason I had decided on using DD or 38D1XJ was because I really don't want it to interfere with the rest of the tonal balance.
Just a subbass boost.
I know that the 38D1XJ is the best in the game atm. My only real concern with using it would be its significant SPL output and that may be too much and drown everything else out.
Seems like there has been a lot more experimentation with the Cl and that may be a safer option as I don't have a measurement rig so fine tuning will be difficult and pretty much done by ear.
Put 4.7 ohm series parallel ohm 38D1X, will give you 15dB lower SPL
 
Jul 26, 2021 at 12:33 PM Post #13,093 of 14,363

Yasser gizouli

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Jul 26, 2021 at 11:25 PM Post #13,095 of 14,363

Jonmakauu

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I am trying to make my own ciem and stumbled into this forum and I have been doing a lot of research lately. But is there like a beginner's guide or any list on where to buy materials? Like drivers, resins, molds etc?

And also a quick question, can you reuse ear impressions for multiple ciem builds? Are there any tips to making them last longer? TIA
 

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