Home-Made IEMs
Jan 19, 2021 at 10:42 PM Post #12,182 of 12,436

musmecca

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My build from yesterday...SR and Sonion 38 build...quite flat I'd say! Eagle eyes will see how I handled mounting the SR's!
 

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Jan 19, 2021 at 10:54 PM Post #12,183 of 12,436

Wgibson

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Nice, I am working on CI and SR now, the SR seems to like some open space in front (otherwise highs get reduced using tubes) so I am using a cheap 10mm dd shell.

I also tried peeling off the foil orifice on the front of the SR, but that had no benefit, and reduced 10k+ response.

Edit: I had to reverse phase on the SR, how did you wire it with the 38?
 
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Jan 19, 2021 at 11:15 PM Post #12,184 of 12,436

musmecca

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Nice, I am working on CI and SR now, the SR seems to like some open space in front (otherwise highs get reduced using tubes) so I am using a cheap 10mm dd shell.

I also tried peeling off the foil orifice on the front of the SR, but that had no benefit, and reduced 10k+ response.

Edit: I had to reverse phase on the SR, how did you wire it with the 38?
I wired them in parallel. SR had a 20 ohm resistor, sonion 38 had a 30 ohm resistor. I used a 1mm Id on the sonion, about 40+mm long, no damper. The SR was placed in heat shrink tubing..protect the wires! Once close to shrunk, I inserted my 2mm x 10 tube and glued into place. As you mentioned, I inserted the tube but not up to the face of the sr...there is purposefully some gap. Damper is white.
 
Jan 20, 2021 at 12:02 AM Post #12,185 of 12,436

Wgibson

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Got a few cheap sonion drivers on taobao that I couldn't find datasheets for, checked impedance, and frequency response from an imm6, both with a short piece of 1mm tube and some tack to seal:

Sonion mystery drivers.jpg

Neither look great, taken at the same volume setting on my sound card FWIW. The 20x53 has a decent curve shape but sub bass rolls off, the 23x62/3 looks hard to drive and not much on the top end, not going to beat out a knowles rab or raf based on just looking at the graph. But might have their place in a multi driver setup. Anyway, in case you were curious about those, there it is.
 
Jan 20, 2021 at 12:46 AM Post #12,186 of 12,436

Wgibson

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I wired them in parallel. SR had a 20 ohm resistor, sonion 38 had a 30 ohm resistor. I used a 1mm Id on the sonion, about 40+mm long, no damper. The SR was placed in heat shrink tubing..protect the wires! Once close to shrunk, I inserted my 2mm x 10 tube and glued into place. As you mentioned, I inserted the tube but not up to the face of the sr...there is purposefully some gap. Damper is white.

2 comments about the SR:

1) I posted a little while back about heat shrinking to it directly, with graphs showing how heat affected the frequency response. Since then I heat a section of tube alone, trim it, and insert the SR driver, to avoid heating the driver. Just have to find the right size heat shrink tube that is a tight fit at full diameter.

2) The CI/SR I am working on has the SR as the zobel resistor which high passes it about 300hz due to the CI's zobel cap, and the SR also has its own zobel, so impedance is very flat. Just a thought if you do another similar build in the future. CI is electrically full range but with very small 0.2mm ID tube as physical low pass, graphs look promising. I still have to finish it still so we'll see how it sounds.
 
Jan 20, 2021 at 4:41 AM Post #12,188 of 12,436

Aldo40

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. CI is electrically full range but with very small 0.2mm ID tube as physical low pass, graphs look promising. I still have to finish it still so we'll see how it sounds.

Exact, 0.5-0,2mm IDx 20mm long makes an extra low pass :wink:
At the end of the tube a small piece of tube of 1mm IDx1-2mm long should be added to facilitate the cleaning of dirt because 0.2 mm can quickly be closed.
they don’t go as far in extrem bass as the 38 Dx1 but they look more tense in bass medium
 
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Jan 20, 2021 at 12:59 PM Post #12,190 of 12,436

musmecca

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actually high pass 2389D series with 47uF
use damper as per taste

and Lpad 38D1XJ with 4.7ohm series parallel
control series resistor to control loudness
add dampers to change and merge the shelf point

and if you are still worried about worsening of sound
get one nP0 ceramic capacitor of super low value(nano farads)

and parallel it with 47uF
this act as a bypass capacitor and nP0 is the best capacitor possible and is used computers for signal integrity.

or if you want to add some musicallity and distortion

go with audiophile electrolyte capacitor and parallel it with nP0
it looks good inside iem too

pyschoacoustic effect
So I fully understand the psychoacoustic effect, I'll run the 47UF to the center tap of a2389D as normal. On either leg I use (depending upon phase) i'll put a very small cap...nano farads. This will give more soudstage? I assume it puts the phase off slightly and that is what gives this effect? I assume this can be done on practically any driver, but is this technique more suited to HF vs Low Frequency?
 
Jan 20, 2021 at 3:01 PM Post #12,191 of 12,436

dhruvmeena96

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So I fully understand the psychoacoustic effect, I'll run the 47UF to the center tap of a2389D as normal. On either leg I use (depending upon phase) i'll put a very small cap...nano farads. This will give more soudstage? I assume it puts the phase off slightly and that is what gives this effect? I assume this can be done on practically any driver, but is this technique more suited to HF vs Low Frequency?
It doesn't do anything
Technically, this technique was made for low performing electrolyte and how to make them signal stable, so old peeps use to add bypass capacitor.

Audiophiles in speaker world think that it sounds like expensive capacitor (I don't know where they get these thing from.... These cap sound topic). Well on measurement simulation done on speaker, it does lower higher order distortion by 0.02% amount only
 
Jan 21, 2021 at 2:34 AM Post #12,192 of 12,436

mattmatt

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Hey guys,

Just wondering if you guys know where to get those switches like what limears uses? Been looking for it for awhile but haven't seen anything similar. I think it's a SPST toggle switch. Any heads up will be deeply appreciated.
 
Jan 21, 2021 at 9:49 PM Post #12,195 of 12,436

dhruvmeena96

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CI-30120 with SR-31843 inside the zobel, also zobel on the SR. Take a guess which one I soldered first :/

Technically

For all other members

Zobelception is a crossover, where you have to carefully choose driver to have a zobel cap which crosses the other driver, and this other driver, flattens the impedance graph respectively.
 

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