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.
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