Home-Made IEMs
Oct 26, 2021 at 11:28 AM Post #13,472 of 14,313

ForceMajeure

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Had a few quick questions related to BA choice.

So I know of a manufacturers switching from sonion 38 + sonion 33 series ba drivers to sonion 38 + Knowles 31 series ba drivers for low/low-mid frequencies. They are keeping the rest of the high frequency range to 8 bellsing twfk ba drivers. So the only real change is the move from sonion 33 ba to Knowles 31 ba. What's the difference here, which one is actually better?

My next question is a separate question. I want to know which of the following configurations would cost more (a rough guesstimate since I don't know all the exact drivers used), assuming they use the same DD.
Configuration A:
2*Knowles RAD-33518 for high frequency 4*Sonion 2600 for mid frequency
1*10.2mm DD for bass
Configuration B:
2*Knowles twfk for ultra high frequency
2*sonion 2389 for mid-high frequency
2*sonion 37 series for mid-low frequency
1*10.2mm DD for bass

And a last bonus question since this one is the most subjective and depends on too many other variables, which of those two configurations do you guys think is best?
1st thing first. The right implementation is what matters and less about this exact ba versus that exact ba. Everything has to be taken into context to be compared and the way things are tuned as a whole package is what ultimately matters.

Assuming when you refer to Knowles 31 series maybe in your case those are equivalent to DTEC (which is kinda equivalent to sonion 33 series in term of vague fr coverage) Then there could be various reasons why those are in use instead of the sonion 33.

Maybe they found out that it has less of a 2nd peak that could help them achieve a better transition, or use a certain peak into their advantage, or or maybe slightly different 1st peak, or slightly different lower mids and bass behavior etc..

Maybe they needed that certain 31 series to work with the rest of the drivers since it offered a certain impedance characteristic, extracting the spl and behavior they needed for the fr range it covers.
Maybe they had issues with sonion supplies and found an alternative that suited them.
Maybe the size of the driver or spout placement worked for them better inside the shell.
Maybe it's slightly cheaper and offers a similar or good result.

There can be a lot of reasons to why they've switched to a different driver. But all these are just assumptions and it's difficult to evaluate how the change exactly works for them.

Regarding your 2nd question
the 1st option might end up cheaper but it's close and can depend on bulk qty
*maybe you meant swfk then the 2nd one should be more expensive depending on the swfk version


Last question
On paper one could think the 2nd option is better because it has more different drivers but who knows...implementation is what matters.
There are more complications with the 2nd config especially using a twfk and 2389 together which is prone to more difficulties, maybe you meant swfk there, then that's different and then I might be inclined to go for the 2nd one as having more potential
But again who knows
 
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Oct 29, 2021 at 5:50 AM Post #13,473 of 14,313

tomekk

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I think multi BA in diy is waste money. It's better to buy a $400 chifi than lose $200 for drivers without a background in either schematics or tuning. It's hard to tune, let assemble a project with 10 drivers, it's not worth it without years of reverse engineering. All BIG companies and their multi ba iems are based on a long reverse engineering, years of reshell service etc.
 
Oct 29, 2021 at 9:49 PM Post #13,474 of 14,313

Wgibson

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Ok, the right side is all glued up, still working on the left. Needs sanding, lacquer, and more circuit design. Very promising frequency response so far. :)

Soundlink 3d printed shell, 13mm dynamic with small orifice as a low pass, 10mm planar, knowles fed-26859 (ferrofluid and type 3 internal damped) no other dampers. Well, the shell has a hole for a knowles damper as a shell vent. I put it next to the planar to see if I can get a more open sound by adjusting damper values.

External 4 pin crossover, I can adjust FED high and sub low pass with capacitors. There is a bit more flexibility, but those are the main things.

Anyway, a few pics:
20211023_175644.jpg20211027_222335.jpg20211029_170502.jpg20211029_194719.jpg

Edit: 3 bore, hand made planar adapter with heat shrink tube and bondic... yeah I need to start 3d printing.

And some frequency response options, with my single planar in there as a reference.

20211023_184627.jpg
13mm DD 10mm planar FED26859 circuit design.jpg
 
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Oct 30, 2021 at 11:46 PM Post #13,475 of 14,313

dhruvmeena96

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I think multi BA in diy is waste money. It's better to buy a $400 chifi than lose $200 for drivers without a background in either schematics or tuning. It's hard to tune, let assemble a project with 10 drivers, it's not worth it without years of reverse engineering. All BIG companies and their multi ba iems are based on a long reverse engineering, years of reshell service etc.
And all those companies come out from here lmao

Designing iem is not hard if you have proper tools and right direction of designing
Soldering skill needs work though
 
Nov 1, 2021 at 11:33 PM Post #13,476 of 14,313

Wgibson

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I still have to assemble the left side, havent listened at all yet, but what do you think about these curves? New project is blue and/or purple, green is my old single planar.

Blue seems like a flatter harmon, purple I don't know what it will sound like, but looks very interesting. Brain rattling sub bass but if you look 100hz and above, typical v shape without any nasty peaks.

11-1-21 13pfed vs old planar.jpg
 
Nov 2, 2021 at 7:42 PM Post #13,477 of 14,313

ForceMajeure

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I still have to assemble the left side, havent listened at all yet, but what do you think about these curves? New project is blue and/or purple, green is my old single planar.

Blue seems like a flatter harmon, purple I don't know what it will sound like, but looks very interesting. Brain rattling sub bass but if you look 100hz and above, typical v shape without any nasty peaks.

Purple sure looks brain rattling like you said :L3000:
Blue might be slightly too scooped in the lower mids
Also it's hard to judge since you use the dayton mic and I am not sure if you've applied some kind of compensation for the pinna and up

What were those black IC you used up there on the fp?
How do you find the consistency between planar units thus far?
 
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Nov 2, 2021 at 8:30 PM Post #13,478 of 14,313

musmecca

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I still have to assemble the left side, havent listened at all yet, but what do you think about these curves? New project is blue and/or purple, green is my old single planar.

Blue seems like a flatter harmon, purple I don't know what it will sound like, but looks very interesting. Brain rattling sub bass but if you look 100hz and above, typical v shape without any nasty peaks.

11-1-21 13pfed vs old planar.jpg
Your work is brilliant!
 
Nov 3, 2021 at 12:23 AM Post #13,479 of 14,313

Xymordos

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Purple sure looks brain rattling like you said :L3000:
Blue might be slightly too scooped in the lower mids
Also it's hard to judge since you use the dayton mic and I am not sure if you've applied some kind of compensation for the pinna and up

What were those black IC you used up there on the fp?
How do you find the consistency between planar units thus far?

I'd like to know too actually, I found the planar matching to be pretty terrible.
 
Nov 3, 2021 at 1:32 AM Post #13,480 of 14,313

Wgibson

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I am not looking forward to matching the left side frequency response... I'll make more planar adapters until they match close enough. Then I will finally realize that I should be 3D printing already.

But the FED-26859 takes care of pinna very consistently, and actually a lot of the treble. I don't mind some variance 10k and up (questionable accuracy with imm6 anyway, but it is very repeatable so relative measurements do have value.) I think I've posted measurements of some common chifi stuff in the past, if anyone really wants to get the flavor of my current measurement setup, but it looks good enough so far. Need an iec711 pretty bad.

The black thing on top is a 4 pin, 1.27mm connector, crossover circuits are built externally. 2 caps and a resistor covers a wide range, but I can get as complex as I want with the circuit. Complete control would need the jack and all drivers pinned out directly, 8 pins. But I have more than adequate control with just 4 pins.
 
Nov 8, 2021 at 1:45 PM Post #13,481 of 14,313

Wgibson

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No surprise, channel imbalance. Need to finish this project and move on, so it's all glued together now, physical tuning is done (except for shell vent.)

I need to measure each driver separately and figure out how to compensate with circuit design.

Needs some sanding and a coat of lacquer, then we'll see how they look.

Edit: to address the comment about curve correction above 10k, no, this was as measured. I was using a really inefficient circuit to get that response from the FED-26859 and planar. Well, technically that response was always there, everything else was just a lot louder.

That is too sensitive to stick with for now, so I'm starting over on circuit design. First I build will be pretty flat, 100hz or so bass shelf, with a lot of treble rolloff above 6k or so. This will also be one of the most efficient circuits, so good starting point for a first impression when listening, finally... next day or so.
 
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Nov 8, 2021 at 9:03 PM Post #13,482 of 14,313

Wgibson

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Ok. I am listening like this (see curve at the end.) It is temporary, my motivation ran low and I needed to start listening to these things. I have not troubleshot drivers yet, that takes more patience than I have at the moment.

The crossover circuit is, in a word, "elegant." This is just a 1uf cap as 26859 high pass. Didn't even measure them, but I think adjusting the exact cap value I can channel match better, for now.

Curve and pic:
11-8-21 13mmDD 10mmPlanar FED26859 TEMP.jpg20211108_195913.jpg
 
Nov 8, 2021 at 10:41 PM Post #13,483 of 14,313

Xymordos

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Ok. I am listening like this (see curve at the end.) It is temporary, my motivation ran low and I needed to start listening to these things. I have not troubleshot drivers yet, that takes more patience than I have at the moment.

The crossover circuit is, in a word, "elegant." This is just a 1uf cap as 26859 high pass. Didn't even measure them, but I think adjusting the exact cap value I can channel match better, for now.

Curve and pic:

You stuffed a 13mm DD in there?! Woah

Is that measurement from a 711? The treble seems to roll off super early.
 
Nov 8, 2021 at 11:12 PM Post #13,484 of 14,313

Wgibson

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Look closer :) imm6 in the photo. No dampers, it sounds brighter than I expected but I am also listening a little too loud, because it is easy to do. I would say that's a good sign.

And yes, I did. I can honestly tell you, there is only one way to fit those 3 drivers in that shell.

20211105_092224.jpg

Edit: to the treble rolloff, yes. This is a temporary "easiest functional circuit." The previous curves were taken at the same volume, you can roughly see the db difference between them. Start at 20hz and just keep lowering db of everything else (except like 6k+ , the idea was to adjust to this level, which would be comparable to my single planar.)

So far I can say that bass shelf rising to about 15hz and not much less at 10hz, seems to have a lot of directional information. Some songs feel like your head is inside the drum set, but at the same time it is subtle... hard to describe, and makes me think some of my other curves would be insane.

Take a close look at the graph scale, this is pretty flat overall.

Dark but clean, I can hear really high cymbal details clearly, they're in the right locations but just not loud, comes out more at high volumes. It doesn't match reality, but does sound natural in a "comfortable to listen" way.
 
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Nov 11, 2021 at 2:28 AM Post #13,485 of 14,313

swtnate

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ALRIGHT! Im ready to move on from brushing on these lacquers. The absolute BEST performing wise has been the clear shellac from luxaprint. Man!!! No bubbles and resists attracting dust and dander. Only thing, pretty dang expensive. Twice the cost in some cases. Also, I wish it built up more to offer a much tighter seal. ANYWAY, Im ready to go the air brush route. I have my air brush and my compressor.

What are some tricks to get consistency correct, not create dry spray or orange peel, and getting lacquer into the nooks and crannies?
 

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