Home-Made IEMs
Oct 11, 2020 at 9:06 AM Post #11,716 of 13,624

dhruvmeena96

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Simple words
It is a zobel
Where zobel acts as a high pass to Tweeter

And can be turned into zobel-ception / crossover-ception

As you can put driver into ever zobel and make.it act as highpass

Do see the polarity because you guys might have to reverse it

But the main part is
The amp sees only the top fullrange driver only

Main idea was to hide drivers in impedance chart.
Conventional crossover can have weird impedances all over the places
 
Oct 11, 2020 at 10:34 AM Post #11,718 of 13,624

Farquarl

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It is not saving energy
It's using the energy which would have back fire to amplifier as would have seen as impedance peak on stock rab

Zobel lowpass the upper freq on driver(where we have those bad imoedance spike) and the parallel a resistor to linearize the impedance and get the signal back

But that zobel eats it's own energy as it's a circuit in the loop

What we are trying to do is reduce zobel energy eaten by its resistor and place a driver there

While also decoupling the RAB from amp and making amp only see a Flatten RAB

If you see the impedance carefully
It shows the impedance what you will expect from single driver being zobelled

This is one way of seeing it

Another way of seeing this is
RAB back generated energy is filtered by zobel so amp can be smooth as possible

And we are using that energy
A zobel filter creates a second path in parrallel to the driver with a reversed impedance effectifely creating a voltage devider and smoothing the imepdance. You are right in that this additional pathway consumes power. and creates heat. So when you said that you wanted to use that wasted energy i assumed you wanted to be more efficient or "save energy". The back EMF with BA´s is so minimal and the output impedance of a normal recent AMP is so low that this has no noticable effect.
 
Oct 11, 2020 at 10:51 AM Post #11,719 of 13,624

dhruvmeena96

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A zobel filter creates a second path in parrallel to the driver with a reversed impedance effectifely creating a voltage devider and smoothing the imepdance. You are right in that this additional pathway consumes power. and creates heat. So when you said that you wanted to use that wasted energy i assumed you wanted to be more efficient or "save energy". The back EMF with BA´s is so minimal and the output impedance of a normal recent AMP is so low that this has no noticable effect.
I mean to say, if this is used in speaker per se.
As this is not only restricted to iem BA.

Plus Back EMF with BA is minimal but the impedance it creates is not. And it makes amp go weird. That extra zobel energy which is being wasted plus that minuscule back energy(because zobel redirects the pathway of back emf to its own resistor as per theory) powers up the wbfk. This plus a zobel on wbfk and everything combined

This system is wasting less energy/effective signal strength compared to stock zobel based system and giving you the benifits if a cross system and a flat impedance. And also that signature zobel sound also.

And the tweeter can be added inside tweeter zobel till infinity also or selecting proper drivers which match main driver zobel resistor can effectively reduce the losses

I just want to say, it's more universal and we can take any theory for it and move forward with design.
It's more cohesive, better for tricking amp to see flat impedance and hiding crossover impedance mess, better for being more efficient and reducing zobel heat losses(which is also tiny, but then as being a DIYer, if we don't go to extreme, then we are not doing it well enough/
 
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Oct 11, 2020 at 11:07 AM Post #11,720 of 13,624

Xymordos

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Simple words
It is a zobel
Where zobel acts as a high pass to Tweeter

And can be turned into zobel-ception / crossover-ception

As you can put driver into ever zobel and make.it act as highpass

Do see the polarity because you guys might have to reverse it

But the main part is
The amp sees only the top fullrange driver only

Main idea was to hide drivers in impedance chart.
Conventional crossover can have weird impedances all over the places


Hmm that's an interesting idea actually, but how would the driver in between affect the zobel values though?
 
Oct 11, 2020 at 11:09 AM Post #11,721 of 13,624

Farquarl

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I mean to say, if this is used in speaker per se.
As this is not only restricted to iem BA.

Plus Back EMF with BA is minimal but the impedance it creates is not. And it makes amp go weird. That extra zobel energy which is being wasted plus that minuscule back energy(because zobel redirects the pathway of back emf to its own resistor as per theory) powers up the wbfk. This plus a zobel on wbfk and everything combined

This system is wasting less energy/effective signal strength compared to stock zobel based system and giving you the benifits if a cross system and a flat impedance. And also that signature zobel sound also.
For that i would like to see a source.

Edit. I don´t want to come of as rude! It is a good idea to potentially make a system more sensitive. I just doubt that a boucherot cell is needed or benificial for anything other than improving crossover behavior.
 
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Oct 12, 2020 at 9:35 AM Post #11,722 of 13,624

larry piencenaves

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Hey guys, new to this thread hoping someone could help me from this..

I tried on modding my wired iems, but when I cut the cable Im suprised i saw 3 braids instead of just 2. How am i supposed to solder this thing? I should just guess and check right?
20201012_203632.jpg
 
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Oct 12, 2020 at 10:51 AM Post #11,723 of 13,624

Farquarl

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Hey guys, new to this thread hoping someone could help me from this..

I tried on modding my wired iems, but when I cut the cable Im suprised i saw 3 braids instead of just 2. How am i supposed to solder this thing? I should just guess and check right?
20201012_203632.jpg
Where did you cut your wire exactly? If you cut it befor the Y section one is the positive of the left one is the positive of the right and one is ground. (Its called stereo sound, crazy i know!)
 
Oct 16, 2020 at 1:58 AM Post #11,727 of 13,624

Arturo Sallas

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Hello Guys.

This is a 4 driver IEM.
HE-31751
CI-22955
WBFK - 30095 - White damper

The logo is done with adhesive Vinyl and covered with resin to seal it. When curing the resin on top of the logo I couldn´t get the whole faceplate to cure, only the center cured poperly, which in this case is convenient because I was only trying to seal the vinyl. But if I wanted to do wood or other materials, how do you guys do to isolate the resin from the air so it cures the whole faceplate?
IMG_4827.jpg
 
Oct 16, 2020 at 10:00 AM Post #11,728 of 13,624

mattmatt

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Hello Guys.

This is a 4 driver IEM.
HE-31751
CI-22955
WBFK - 30095 - White damper

The logo is done with adhesive Vinyl and covered with resin to seal it. When curing the resin on top of the logo I couldn´t get the whole faceplate to cure, only the center cured poperly, which in this case is convenient because I was only trying to seal the vinyl. But if I wanted to do wood or other materials, how do you guys do to isolate the resin from the air so it cures the whole faceplate?
IMG_4827.jpg
You don't have to. Cure it longer than usual, wipe of the excess/inhibition layer and sand it before lacquer. That's how I do mine.

Neat faceplate! How did you manage to cut it?
 

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Oct 16, 2020 at 12:34 PM Post #11,729 of 13,624

musmecca

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Hello Guys.

This is a 4 driver IEM.
HE-31751
CI-22955
WBFK - 30095 - White damper

The logo is done with adhesive Vinyl and covered with resin to seal it. When curing the resin on top of the logo I couldn´t get the whole faceplate to cure, only the center cured poperly, which in this case is convenient because I was only trying to seal the vinyl. But if I wanted to do wood or other materials, how do you guys do to isolate the resin from the air so it cures the whole faceplate?
IMG_4827.jpg
I mix my resin then pour onto a sheet of glass. I hit it for 30 seconds to get a skin (otherwise it will flow too thin when glass is placed on top), then I place another sheet of glass on top. It makes a perfect thickness without any tacky layer at all. Once removed, put a logo on then use lac 3 to finish it all.
 
Oct 17, 2020 at 3:05 PM Post #11,730 of 13,624

johnchpark

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6BA build.
1st attempt on the shell and it straight ugly.
LR tuning also off...the Green line (right) is the intended tuning and was how it measured out of the shell while initially tuning. Not sure what happened with the purple (left) side...maybe some wires touching inside...
 

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