Home-Made IEMs
Jul 22, 2021 at 9:36 AM Post #13,066 of 15,971
Anyone calibrated the Apple Dongle as Soundcard? I wanted more precision but it does weird stuff when I try to calibrate
 
Jul 22, 2021 at 2:19 PM Post #13,067 of 15,971
Anyone calibrated the Apple Dongle as Soundcard? I wanted more precision but it does weird stuff when I try to calibrate

I personally had zero luck with loopback calibration with the Apple Dongle, so what I did instead was to measure the same IEM with a calibrated card, then with the Apple Dongle, exported both graphs as text files, then wrote a Python program to subtract between the two output files and used that as my calibration file.
 
Jul 22, 2021 at 3:26 PM Post #13,068 of 15,971
I personally had zero luck with loopback calibration with the Apple Dongle, so what I did instead was to measure the same IEM with a calibrated card, then with the Apple Dongle, exported both graphs as text files, then wrote a Python program to subtract between the two output files and used that as my calibration file.
Could you send it to me? As it will be identical for the dongle :D
 
Jul 23, 2021 at 2:15 AM Post #13,069 of 15,971
Could you send it to me? As it will be identical for the dongle :D

Sure. But a lot of caveats:
1. I now realize you're likely talking about the USB-C dongle which I don't have, while I use a lightning dongle xD
2. My particular dongle has gigachad bass roll-off, where I have seen some without and some with. YMMV to whoever uses this.
3. It is not SPL calibrated at all.
 

Attachments

  • dongle comp.txt
    10.3 KB · Views: 0
Last edited:
Jul 23, 2021 at 6:41 AM Post #13,070 of 15,971
Sure. But a lot of caveats:
1. I now realize you're likely talking about the USB-C dongle which I don't have, while I use a lightning dongle xD
2. My particular dongle has gigachad bass roll-off, where I have seen some without and some with. YMMV to whoever uses this.
3. It is not SPL calibrated at all.
Thanks👍 I do have the USB C one with gigachad bass linearity😂
 
Jul 24, 2021 at 12:40 AM Post #13,071 of 15,971
I recently gave a listen to an old set.
I had built a Savant (ED 29689 + ED 30761) a few years ago and it gets almost no ear time. Simply because it doesn't have near enough bass output.
I love the midrange and treble is ok. Clarity is really good.
So it got me thinking about adding a bass driver of some sort.
I've narrowed down choices to either 38D1XJ007Mi/8A or a Dynamic

Has anyone done something similar to this? Any advice on which route to pursue?
 
Jul 24, 2021 at 1:44 PM Post #13,072 of 15,971
I recently gave a listen to an old set.
I had built a Savant (ED 29689 + ED 30761) a few years ago and it gets almost no ear time. Simply because it doesn't have near enough bass output.
I love the midrange and treble is ok. Clarity is really good.
So it got me thinking about adding a bass driver of some sort.
I've narrowed down choices to either 38D1XJ007Mi/8A or a Dynamic

Has anyone done something similar to this? Any advice on which route to pursue?
Yes! I did a few builds (MASM, MASM Pro) and no matter what, I wasn't feeling the bass. Someone (mattmatt possibly....i'll find and give credit) did a study of bass drivers with varying tube diameters and types. It got me thinking of the best configuration for an add-on sub for just these situations. . If you were like me, I had a very good looking build I didn't want to destroy so this is the solution. I used a CI with an ALUMINUM 1mm tube. I drilled a small hole in the canal part of the IEM so I could simply slide the tube into place without destroying anything else. Lenght of tube is inconsequential becasue it's a sub. Once the tube is in place, I got a 2mm piece of pvc tubing as a connector only. I put a green damper...one of the tiny knowles without the metal shell (1.5 mm?) and put it directly on the spout of the CI. I sealed the tubes, did my electrical and resealed it all. It is my best sounding rig as the aluminum tube is fast, no flub, and with the damper it doesn't interfere with other frequencies. I've done this a few times and am very pleased.
 

Attachments

  • 20210217_170102.jpg
    20210217_170102.jpg
    506.6 KB · Views: 0
  • 20210217_170106.jpg
    20210217_170106.jpg
    1 MB · Views: 0
  • 20210724_122648.jpg
    20210724_122648.jpg
    1.1 MB · Views: 0
Last edited:
Jul 24, 2021 at 1:59 PM Post #13,073 of 15,971
Yes! I did a few builds (MASM, MASM Pro) and no matter what, I wasn't feeling the bass. Someone (mattmatt possibly....i'll find and give credit) did a study of bass drivers with varying tube diameters and types. It got me thinking of the best configuration for an add-on sub for just these situations. . If you were like me, I had a very good looking build I didn't want to destroy so this is the solution. I used a CI with an ALUMINUM 1mm tube. I drilled a small hole in the canal part of the IEM so I could simply slide the tube into place without destroying anything else. Lenght of tube is inconsequential becasue it's a sub. Once the tube is in place, I got a 2mm piece of pvc tubing as a connector only. I put a green damper...one of the tiny knowles without the metal shell (1.5 mm?) and put it directly on the spout of the CI. I sealed the tubes, did my electrical and resealed it all. It is my best sounding rig as the aluminum tube is fast, no flub, and with the damper it doesn't interfere with other frequencies. I've done this a few times and am very pleased.
I'm interested in the aluminum difference, what do you mean with "no flub"?
 
Jul 24, 2021 at 2:07 PM Post #13,074 of 15,971
Yes! I did a few builds (MASM, MASM Pro) and no matter what, I wasn't feeling the bass. Someone (mattmatt possibly....i'll find and give credit) did a study of bass drivers with varying tube diameters and types. It got me thinking of the best configuration for an add-on sub for just these situations. . If you were like me, I had a very good looking build I didn't want to destroy so this is the solution. I used a CI with an ALUMINUM 1mm tube. I drilled a small hole in the canal part of the IEM so I could simply slide the tube into place without destroying anything else. Lenght of tube is inconsequential becasue it's a sub. Once the tube is in place, I got a 2mm piece of pvc tubing as a connector only. I put a green damper...one of the tiny knowles without the metal shell (1.5 mm?) and put it directly on the spout of the CI. I sealed the tubes, did my electrical and resealed it all. It is my best sounding rig as the aluminum tube is fast, no flub, and with the damper it doesn't interfere with other frequencies. I've done this a few times and am very pleased.
I don't remember about it so it's probably not me you should give credit for but did experiments with it but find it's way too laborious for me so I stuck with PVC tubing. Tube length, even for sub has effect tho as for my study and experience. Tho high frequencies are much more susceptible to change. Even damper placement makes a huge difference with tweeters.
 
Jul 24, 2021 at 2:27 PM Post #13,075 of 15,971
I'm interested in the aluminum difference, what do you mean with "no flub"?
When I say no flub, it means it is very fast, transients are very accurate, and there isn't any distortion caused by varying playing styles even when you hit the lowest notes. Some speakers sound great and fast when you're playing higher in the register, but "flub...crap out...become mush" when you hit low sub notes. Sorry...life long guitar player here! There is something special about the CI with an aluminum 1mm tube.....I played with many configurations and I got lucky with the combo. I did try the sonion 38, but it was soo loud I would have had to re-pad everything and I had already epoxied my caps/resistors/connections in place...this was the easiest drop in solution for me, especially since I had zobeled the already installed drivers. I'll go through my notes and see if I can find exactly what the values were.
 
Jul 24, 2021 at 2:34 PM Post #13,076 of 15,971
I don't remember about it so it's probably not me you should give credit for but did experiments with it but find it's way too laborious for me so I stuck with PVC tubing. Tube length, even for sub has effect tho as for my study and experience. Tho high frequencies are much more susceptible to change. Even damper placement makes a huge difference with tweeters.
The original poster if I recall was in Oklahoma City...the only thing worse than my building skills is my computer skills and memory! Anyways, complteley agree with damper placement, length, etc. Dhruv had suggested a few builds to me using a 1mm tube with long lengths just as a sub...nothing more. He had said the CI or 38 would be more diffuse field if used in this manner. I wish I had kept better notes! I consider myself lucky....not talented with this one!
 
Jul 24, 2021 at 2:54 PM Post #13,077 of 15,971
Yes! I did a few builds (MASM, MASM Pro) and no matter what, I wasn't feeling the bass. Someone (mattmatt possibly....i'll find and give credit) did a study of bass drivers with varying tube diameters and types. It got me thinking of the best configuration for an add-on sub for just these situations. . If you were like me, I had a very good looking build I didn't want to destroy so this is the solution. I used a CI with an ALUMINUM 1mm tube. I drilled a small hole in the canal part of the IEM so I could simply slide the tube into place without destroying anything else. Lenght of tube is inconsequential becasue it's a sub. Once the tube is in place, I got a 2mm piece of pvc tubing as a connector only. I put a green damper...one of the tiny knowles without the metal shell (1.5 mm?) and put it directly on the spout of the CI. I sealed the tubes, did my electrical and resealed it all. It is my best sounding rig as the aluminum tube is fast, no flub, and with the damper it doesn't interfere with other frequencies. I've done this a few times and am very pleased.
CI is not a subwoofer
I repeat
CI is not a subwoofer

Its a fullrange driver with wrong pinnae peak

If you need sub
Go for 38D1XJ

Or try to cross CI
 
Jul 24, 2021 at 8:23 PM Post #13,078 of 15,971
CI is not a subwoofer
I repeat
CI is not a subwoofer

Its a fullrange driver with wrong pinnae peak

If you need sub
Go for 38D1XJ

Or try to cross CI
Any you are correct! 38 is a much more powerful sub woofer. It's SPL is much higer than the CI, which is great in original design. But this was a retrofit, which made me think about how to play with the original configuration without destroying what I had already built. You mentioned crossing the CI: I simply used mechanical means of tube material, diameter, length, and filter to accomplish the desired result. I did find the reference...it was Wgibson who did the analysis.
 
Jul 24, 2021 at 8:49 PM Post #13,079 of 15,971
Any you are correct! 38 is a much more powerful sub woofer. It's SPL is much higer than the CI, which is great in original design. But this was a retrofit, which made me think about how to play with the original configuration without destroying what I had already built. You mentioned crossing the CI: I simply used mechanical means of tube material, diameter, length, and filter to accomplish the desired result. I did find the reference...it was Wgibson who did the analysis.
Some use double CI with Double Yellow to for subs. :D A really well known and expensive use this setup.

I really like the CI to. :D
 
Jul 24, 2021 at 8:50 PM Post #13,080 of 15,971
Any you are correct! 38 is a much more powerful sub woofer. It's SPL is much higer than the CI, which is great in original design. But this was a retrofit, which made me think about how to play with the original configuration without destroying what I had already built. You mentioned crossing the CI: I simply used mechanical means of tube material, diameter, length, and filter to accomplish the desired result. I did find the reference...it was Wgibson who did the analysis.
Also, adding a low pass with CI kind of flattens it's bloat from 20-100 iirc.
 

Users who are viewing this thread

Back
Top