Home-Made IEMs
Jan 19, 2021 at 4:13 AM Post #12,167 of 12,426

mattmatt

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General question, which do you finalize first? Assuming you're happy with circuit design and preliminary frequency response measurements.

Do you finalize physical stuff like attaching and gluing tubing, dampers, verify fit in shell.

Or do you do all the wiring first? And risk having to rework or damaging something as you try to get it packed in a shell after it is wired?
I attach my tubing first so there's less stress on the solder tabs when handling them.

I now also do "wiring harness" 2nd. From the socket to the crossover components then solder it to the drivers with the tubes. :)
 
Jan 19, 2021 at 9:14 PM Post #12,169 of 12,426

dhruvmeena96

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Jh audio and some other companies they talking in the internet about phase acoustic cancellation and big dips in the frequency response.

To be honest I would love to make my iem with a phase issue and a big dip at 200 hz.

One question guys , the resistor in a passive crossover, can I use any value I want ?
I'm very confused with this .
it affects impedance so no
 
Jan 19, 2021 at 9:58 PM Post #12,171 of 12,426

Wgibson

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Yes i know,
you are right.
My question wasn't clear.
Ι wanted to lower a bit the volume of the 2 38D1XJ00.
And with a second order crossover this isn't possible i believe.

Something wrong with just a resistor in series? Or just use one, were you able to test fitting all that in a shell yet?
 
Jan 19, 2021 at 10:08 PM Post #12,175 of 12,426

Wgibson

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Guess I need to work on testing drivers without soldering, don't want to solder to a driver twice if I can avoid it. I have multimeter tweezer leads (for checking surface mount components) so I could try just manually holding those to the driver solder pads while measuring.
 
Jan 19, 2021 at 10:21 PM Post #12,177 of 12,426

dhruvmeena96

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I'm very confused at this moment with all this components because I believe they can worsen the sound quality if I do something wrong .

Imagine i can fit 2 x 38D1XJ00 , 1 x 2389D and 1 x EST65QB02 in soundlinks shell which is medium size shell.
It depends the skills .
first of all
https://www.audioholics.com/loudspeaker-design/crossovers

all you read about crossover and crossover damaging the sound is 90% hoax
if you can adjust phase and impedance
crossover have a huge advantage
a ceramic capacitor wont worsen the sound
neither a metal film resistor

the 10% truth about crossover damaging the sound quality is wasted energy in heat from these component
or capacitor peizo effect

bro, we have technically done everything here in this thread

and a properly designed system offers way less IMD(to the level of none), way better transient and impulse and the only con is just very minute signal lost on component, which can be compensated with increasing the volume
plus, resistor, inductor and caps behave as linear instead of non linear devices

i can go on and on.

components dont make sound worse, its the application
 
Jan 19, 2021 at 10:23 PM Post #12,179 of 12,426

dhruvmeena96

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I want to pull out the low frequencies from the 2389D
and make a low pass filter for the 38D1XJ00 at 200 hz
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
 
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Jan 19, 2021 at 10:33 PM Post #12,180 of 12,426

musmecca

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General question, which do you finalize first? Assuming you're happy with circuit design and preliminary frequency response measurements.

Do you finalize physical stuff like attaching and gluing tubing, dampers, verify fit in shell.

Or do you do all the wiring first? And risk having to rework or damaging something as you try to get it packed in a shell after it is wired?
1. I always wire drivers first on a vice, no tubes, as this is critical and requires a stable platform.
2. I attach tubes next.
3. I wire everything together including socket and crossover.
4. I then test output and FR, recognizing it isn't tweaked until it's in the shell. Sometimes I install dampers here.
5. I already have my faceplates and shells drilled and prepped. Depending on the finish, sometimes I attach the faceplates with no electronics and finish edges, dip in laq 3, then simply razor the face back off to receive electronics.
6. Install everything....note I incorporate strain relief (simply glue litz to BA's) and test 1 more time before buttoning up.
7. With extra tube sticking out of bore, I bondic in place...then simply cut tubes flush. Faceplate reattached.
8. Final test then final light lac 3.
 

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