Home-Made IEMs
Feb 2, 2019 at 7:21 AM Post #8,041 of 16,107
Well, this thread was started in 2009
i mean to say, it is 10years old
lol
I have learnt a lot from this thread


by the way
@piotrus-g
Knowles 33357 is also used in Fiio FA1, which is making rave reviews in china and india
From design point of view, it is driver and tube with cavity in nozzle acting like a stepped horn with some sort of damper

and i am seeing a lot of iem popping out with the driver you used first(as i know, FIBAE 1 only comes on google till date when you search knowles 33357)

Well, if this driver is now open for other manufacturers, how can i order it.

I had some experience with FED. It sounds amazing but the treble is not there. It can only be used as Midrange driver. FED bass is slightly more controlled than ED but doesnt have the power of CI. FED is linear impedance and phase but cannot solve the treble area
 
Feb 2, 2019 at 8:49 AM Post #8,042 of 16,107
Guys, I did it! I really managed to build @piotrus-g s scary crossover design with traditional components (no SMD).

It just barely fits into my shells and you don't imagine the pain I went through. One stopped working as the soldering pad of the TWFK broke off, I had to rebuild it. Then it stopped working again but after gluing the tubes in place, but this time I was able to fix it by soldering inside the shell ... Next time I'll build it using SMD.

Anyway for those of you thinking about going the same route, build details in the Spoiler.

IMG_3546.jpg

I soldered everything and covered the CI crossover in some resin, to keep it in a nice package.

Scary Crossover.png

Scary Crossover Distortion.png


IMG_3555.jpg


Looks a little cramped.

IMG_3563.jpg


Ready for polishing


Sound wise it has some pros and cons compare to the GV. Upper mids and highs are definitively slightly better, less harsh and more pleasing than the GV. Bass is a little less compared to the GV with open vents, but by no means too little.
Hoewever these are definitively V shaped, which is not my cup of tea. I grew up with the Sennheiser signature and I like a warmer signature.
I tried modifying them by adding different dampers, but everything I did just threw them off balance and didn't improve them at all. The GV I got to sound warm with orange dampers on highs and lows.

But that is entirely a personal preference, many just love this signature. This signature works especially good for Rock, Metal, Jazz but I do not like it with electronic or classical music.

So what to build next? Are there any recipes that produce a less V shaped an warmer sound signature? Did anyone try @Shilohsjustice HODVTEC + TWFK design? Or @Savant ED29689 + ED30761? Is any of them warmer?
 
Feb 2, 2019 at 8:59 AM Post #8,043 of 16,107
Guys, I did it! I really managed to build @piotrus-g s scary crossover design with traditional components (no SMD).

It just barely fits into my shells and you don't imagine the pain I went through. One stopped working as the soldering pad of the TWFK broke off, I had to rebuild it. Then it stopped working again but after gluing the tubes in place, but this time I was able to fix it by soldering inside the shell ... Next time I'll build it using SMD.

Anyway for those of you thinking about going the same route, build details in the Spoiler.


I soldered everything and covered the CI crossover in some resin, to keep it in a nice package.






Looks a little cramped.



Ready for polishing


Sound wise it has some pros and cons compare to the GV. Upper mids and highs are definitively slightly better, less harsh and more pleasing than the GV. Bass is a little less compared to the GV with open vents, but by no means too little.
Hoewever these are definitively V shaped, which is not my cup of tea. I grew up with the Sennheiser signature and I like a warmer signature.
I tried modifying them by adding different dampers, but everything I did just threw them off balance and didn't improve them at all. The GV I got to sound warm with orange dampers on highs and lows.

But that is entirely a personal preference, many just love this signature. This signature works especially good for Rock, Metal, Jazz but I do not like it with electronic or classical music.

So what to build next? Are there any recipes that produce a less V shaped an warmer sound signature? Did anyone try @Shilohsjustice HODVTEC + TWFK design? Or @Savant ED29689 + ED30761? Is any of them warmer?

Nice job!
Savant is neutral-ish mild V. But you can make it warmer by using higher Ohm resisor and/or red/orange damper on ED29689.
 
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Feb 2, 2019 at 10:02 AM Post #8,044 of 16,107
Guys, I did it! I really managed to build @piotrus-g s scary crossover design with traditional components (no SMD).

It just barely fits into my shells and you don't imagine the pain I went through. One stopped working as the soldering pad of the TWFK broke off, I had to rebuild it. Then it stopped working again but after gluing the tubes in place, but this time I was able to fix it by soldering inside the shell ... Next time I'll build it using SMD.

Anyway for those of you thinking about going the same route, build details in the Spoiler.


I soldered everything and covered the CI crossover in some resin, to keep it in a nice package.






Looks a little cramped.



Ready for polishing


Sound wise it has some pros and cons compare to the GV. Upper mids and highs are definitively slightly better, less harsh and more pleasing than the GV. Bass is a little less compared to the GV with open vents, but by no means too little.
Hoewever these are definitively V shaped, which is not my cup of tea. I grew up with the Sennheiser signature and I like a warmer signature.
I tried modifying them by adding different dampers, but everything I did just threw them off balance and didn't improve them at all. The GV I got to sound warm with orange dampers on highs and lows.

But that is entirely a personal preference, many just love this signature. This signature works especially good for Rock, Metal, Jazz but I do not like it with electronic or classical music.

So what to build next? Are there any recipes that produce a less V shaped an warmer sound signature? Did anyone try @Shilohsjustice HODVTEC + TWFK design? Or @Savant ED29689 + ED30761? Is any of them warmer?
Well

First of all, instead of pure series resistor, go for L-pad on CI drivers.

Reason

L-pad keeps the voice coil resistance same, which leads to proper attenuation compared to series resistance.

Only tweeter has faired better with series resistance.

On bass driver, you will always want the Ztotal to be equal to Zo.

If we put series resistance, it adds up impedance, increase the peak of resonant and increase the area of peak, which lead to uncontrolled behaviour.

Well CI does fair better in control compared to HODVTEC but I went with L pad.

On TWFK I went two 330ohm damper

One directly in front of TWFK nozzle and one at center.


Go for savant build if you want neutral sound.
But some tweaks I have mentioned above for savant build above.

Go for L-Pad instead of series 20ohm. Full range driver shows a lot of bad behaviour with series resistance. You can see the reviews and analysis as people are claiming it doesn't sound as good as it measure.

They tell the female vocals are shouty and treble is brittle.
That is because of added distortion of 20ohm resistance and uncontrolled voice coil.


ED29689 is 3.65 ohm and you require 16.23dB attenuation compared to ED30761

Second thing is
Please dont flatten out the 2mm tube on nozzle like noble. It creates pressure at end, which can make treble sound really bad.

And do experiment with a super low pass subwoofer as noble savant lack good subbass air.

Savant is like etymotic with bad treble and extended mid bass and the soundstage feeling like it was stretched.
I mean to say, it is not bad and is nice mid focused, really well done IEM. But the treble is sort of really not good feeling. It feels like it is distorting. Well that is because

Ety er4 was just ED29689 with 20ohm and green damper at end, it never showed the treble issues.

Here the green damper is near the nozzle(ED29689) and other driver(ED30761) is without resistance, full range with a red damper also near.

This make the driver treble to come out and the first ED(green) in conjunction to other ED(red, no nozzle) is technically more impedant with the resonance shifting higher.

As you will see the diagram of savant, the impedance tell the whole story

As you can see, the rise from 250Hz is not normal plus the dip near 4kHz should be in margin of 10% to 15% more value of DC resistance of both driver.

This way, the driver works pretty normally on any given amp.

Savant 4kHz and above is brittle

But after L-pad the issue was more so solved
Savant Z.png
 
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Feb 2, 2019 at 10:07 AM Post #8,045 of 16,107
Well, this thread was started in 2009
i mean to say, it is 10years old
lol
I have learnt a lot from this thread


by the way
@piotrus-g
Knowles 33357 is also used in Fiio FA1, which is making rave reviews in china and india
From design point of view, it is driver and tube with cavity in nozzle acting like a stepped horn with some sort of damper

and i am seeing a lot of iem popping out with the driver you used first(as i know, FIBAE 1 only comes on google till date when you search knowles 33357)

Well, if this driver is now open for other manufacturers, how can i order it.

I had some experience with FED. It sounds amazing but the treble is not there. It can only be used as Midrange driver. FED bass is slightly more controlled than ED but doesnt have the power of CI. FED is linear impedance and phase but cannot solve the treble area
I can't comment on that

Guys, I did it! I really managed to build @piotrus-g s scary crossover design with traditional components (no SMD).

It just barely fits into my shells and you don't imagine the pain I went through. One stopped working as the soldering pad of the TWFK broke off, I had to rebuild it. Then it stopped working again but after gluing the tubes in place, but this time I was able to fix it by soldering inside the shell ... Next time I'll build it using SMD.

Anyway for those of you thinking about going the same route, build details in the Spoiler.


I soldered everything and covered the CI crossover in some resin, to keep it in a nice package.






Looks a little cramped.



Ready for polishing


Sound wise it has some pros and cons compare to the GV. Upper mids and highs are definitively slightly better, less harsh and more pleasing than the GV. Bass is a little less compared to the GV with open vents, but by no means too little.
Hoewever these are definitively V shaped, which is not my cup of tea. I grew up with the Sennheiser signature and I like a warmer signature.
I tried modifying them by adding different dampers, but everything I did just threw them off balance and didn't improve them at all. The GV I got to sound warm with orange dampers on highs and lows.

But that is entirely a personal preference, many just love this signature. This signature works especially good for Rock, Metal, Jazz but I do not like it with electronic or classical music.

So what to build next? Are there any recipes that produce a less V shaped an warmer sound signature? Did anyone try @Shilohsjustice HODVTEC + TWFK design? Or @Savant ED29689 + ED30761? Is any of them warmer?
Well build the triple driver it's much more balanced and less V-shaped.
 
Feb 3, 2019 at 3:59 AM Post #8,048 of 16,107
@piotrus-g I can’t thank you enough for all the advice you dropped in this thread.

What do you mean by ‚the triple driver‘? Is that a recipe of yours in this thread I missed? I would happily follow your advice.
Thanks!
Yeah, there is 3-driver design in this thread based on CI+TWFK i believe I posted it before the 4-driver
 
Feb 3, 2019 at 6:31 AM Post #8,049 of 16,107
Series, hmmmm nice

best way to increase driver, dB in safe manner plus get the same impedance graph(More impedance only) as one driver...



hmm smart bro
@Ivan TT

i want to correct myself

If you run 4 drivers in series vs 4 driver parallel at same volume

series one gives a lot more distortion
because of added resistance, inductance and capacitance of driver

but added safety is lower overall driver

You are safe, as it doesn't go loud 4 RAB parallel due to high impedance and resistance


as i was stimulating the design on Comsol

2 x (2x RAB set in series) parallel terminated to two wires connected to zobel before MMCX or 2pin connector

The parallel keeps the voltage same, divides the current for 2 set of series RAB

the dual series RAB then divides the Voltage while keeping the current same

This leads to 1/2 voltage, 1/2 current compared to Full amps and 1/4 voltage

this will keep the RAB at 22ohm DC, 33ohm 500Hz and 7.8mH 500Hz property same, but will flatten out the phase slightly, and lower the value and frequency of resonant peak

plus add zobel

41.25ohm metal foil resistance
4.6uF cap


This leads to better dynamic range, better heat transfer(If any, as BA is small), lower distortion, more volume and more extension

even though you did 1/4 voltage, the ampere going in still something to care for. plus change in single driver property due to added impedance of all other driver. If you series them first(in pairs) and then parallel it with two terminal wire (parallel drivers +ve connected and -ve connected)

all the parameters return back to single RAB while all the driver diaphragm are moving less, more surface area for driver(the two reason will reduce air reactive resistance and increase reactive load while bigger surface area will move resonant impedant peak from 3kHz to somewhat lower than 1KHz as its surface area would be bigger than a single CI while damping it)

The reason in brackets are more than enough


the best way to make BA setup sound like speaker is go 16 RAB in sets of 4 RAB

all doing full range and have 22ohm DC resistance. That setup would be fun as heck as the driver surface area would increase dramatically compared to 1kHz and will drop the resonant peak way lower(I mean way lower, plus damp it)
 
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Feb 4, 2019 at 12:47 AM Post #8,051 of 16,107
That would be FUN!
@CoiL @Ivan TT

i was not aware that you both were on opamp thread lol

Dont roll anything on Aune of yours @CoiL

@Ivan TT try to keep the total impedance of driver same. more driver with impedance of single driver will lead to lower diaphragm movement, more sensitivity, same or slighlty more loudness and way bigger dynamic range compared to single driver

and the treble response will rise while flattening the impedance slightly down and the zobel will clean up the treble peaks

you gave me the inspiration for simple 16 driver, without crossovers, without dampers(or slight dampers).
 
Feb 4, 2019 at 1:14 AM Post #8,052 of 16,107
you gave me the inspiration for simple 16 driver, without crossovers, without dampers(or slight dampers).
Awesome!

I don't know if you tried 4 driver set up, so apologies if I'm giving you unnecessary advise but give it a go, especially since RAF's are dirt-cheap and could be housed in a medium sized shell with a bit of front air and no individual tubing required (just #13 tubing in the nozzle to accommodate dampers, I would try all in the grey-green spectrum).

I cannot quite confirm that my impressions of 2 or 4-driver RAB in series set up match your descriptions and rationale, quite the opposite: I note that the peaks seem to have smoothed out and LF response improved in 2-driver and to a lesser degree of improvement above 2 driver 4-driver set up. Alas practical outcome will not always be as suspected, but it also brings some good results too, all I can say is that my 4 driver RAB-based set up is exceptionally good sounding and I have a total of 16 RAFs in the mail (including shells to house them in).

I will try Zobel as you suggest (at some stage, hopefully soon), but the most important things is that I am content with the way my projects sound (well, except for a single-driver RAB) and thourowly enjoy the music I love! :)
 
Feb 4, 2019 at 1:35 AM Post #8,053 of 16,107
Awesome!

I don't know if you tried 4 driver set up, so apologies if I'm giving you unnecessary advise but give it a go, especially since RAF's are dirt-cheap and could be housed in a medium sized shell with a bit of front air and no individual tubing required (just #13 tubing in the nozzle to accommodate dampers, I would try all in the grey-green spectrum).

I cannot quite confirm that my impressions of 2 or 4-driver RAB in series set up match your descriptions and rationale, quite the opposite: I note that the peaks seem to have smoothed out and LF response improved in 2-driver and to a lesser degree of improvement above 2 driver 4-driver set up. Alas practical outcome will not always be as suspected, but it also brings some good results too, all I can say is that my 4 driver RAB-based set up is exceptionally good sounding and I have a total of 16 RAFs in the mail (including shells to house them in).

I will try Zobel as you suggest (at some stage, hopefully soon), but the most important things is that I am content with the way my projects sound (well, except for a single-driver RAB) and thourowly enjoy the music I love! :)
I suggested the design after studying, clearing my doubts here and there....
Well, in the end, its you and your house sound.

Well it is still better than 1 though

And you gave me inspiration for more driver no cross simplicity.

LoL

Well I stimulated yours and mine on comsol multi physics
Inserting frequency graph in excel and impedance

And importing file, so I can get somewhat near results.

I have tried RAF single, dual build

And with your resonator


It just feels good, the resonator doesn't let the peak form
 
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