Ivan TT
500+ Head-Fier
Yup, that was the inspiration, notice drivers firing into a chamber directly (no tubing) with single tubing on the other side, as described above:
Home-Made IEMs
- Thread starter Bilavideo
- Start date
dhruvmeena96
Headphoneus Supremus
best driver is
RAF-32873
ask why?
See the paper knowles attached with it. Mind blown
From driver reliability in Newton force test noted on exact
Imepdance graph given with so much detail
real diy driver is this
We can engineer it to max plus it is so much more abuse taker
it is like 2JZ GTE engine in Toyota Supra
Extreme in build, cheap in price and attach a turbo for 1000HP and it will take it easily
15N of force handling limit on body, plus so much exact detail and tighter tolerance
15$ for pair and frequency graph looks better than RAB counterpart
Well this crazy
RAF-32873
ask why?
See the paper knowles attached with it. Mind blown
From driver reliability in Newton force test noted on exact
Imepdance graph given with so much detail
real diy driver is this
We can engineer it to max plus it is so much more abuse taker
it is like 2JZ GTE engine in Toyota Supra
Extreme in build, cheap in price and attach a turbo for 1000HP and it will take it easily
15N of force handling limit on body, plus so much exact detail and tighter tolerance
15$ for pair and frequency graph looks better than RAB counterpart
Well this crazy
I did something like that with one of my designs and ended up with a design that had great separation and lots of air. Probably pure coincidence but loved the results.
dhruvmeena96
Headphoneus Supremus
i kinda got into the design of yoursYup, that was the inspiration, notice drivers firing into a chamber directly (no tubing) with single tubing on the other side, as described above:
kinda cool and out of the box thinking
i got my friend simulate your design on virtual environment
well what is the length of the tube, the standard 13 tube
I can help you refine it, without changing anything
it is the first attempt i have seen(going in series)
and i think, well it is way to hard to drive though, but fixes a lot of thing
1. peaky treble fix(Cavity and Series + damper).
2. Bass control(This will be too tight, super sharp bass on timing)
3. Overall speed and timing of hit
4. Distortion fix
5. Impedance graph will remain structurally same as single driver
but issues are from what he is telling me
1. due to high resistance.
88ohm DC resistance
132ohm 500 Hz nominal impedance
198ohm on 1kHz
250ohm on 3kHz
the issue is 250ohm at 3kHz. This thing may also create the feeling of of space, but extreme vocally sound may not get texture of crispiness and rasp. 3kHz have vocal harmonic details.
you may need to fix this area
but from what i see, that your tubing is small, it may not be an issue, but still asking the length of tubing.
and the space is correct for 4mm
but from your design i can see a verysmall fault
the 4mm is from tip of body rather than spout of BA. plus seal the surrounding body near the sprout so that it becomes flat surface with earlier spout area becoming holes. then make a space of 4mm(3.9mm but doesnt matter).
This will fix some internal hazzyness.
and shift the 660ohm damper in between of the tube.
because the cavity is already reducing the pneumatic pressure from BA, which then flows in tube, the 660ohm damper in end becomes too restrictive, which may kill some higher harmonic detail. moving it inside, may get some effect of pneumatic pressure penetration on damper, which make the air flow better and some extreme HF can raise.
experiment with zobel , because BA skyrocket in impedance at HF production and you series it, so the resistance would be very high, and you may wanna fix that
all my tips, may get the naunces of HF right
If you fix the HF extension, this can be a killer setup, because you have already achieved perfect mids and bass.
just slightly
plus
Since the two driver's electrical impedances and back EMFs are identical, the back EMF of one driver is just right to cancel the back EMF from the other and vice versa. This keeps the voltage over each of the drivers to exactly half the total driving voltage. This would not have been the case with a series resistor or if you were to put the hand on one of the drivers to keep the cone at standstill.
But I think that this way of thinking is more complicated than the simple voltage divider with two identical impedances.
So, the bottom line is; connecting identical drivers in series is OK, it does not affect Qts.
Edit: you can also see it from the equation for Qes:
Qes=2*pi*fs*Mms/Res, Res=(Bl)^2/Re
If you add a driver in series and see the two drivers as one, B and fs would stay the same, Mms would double, l would double, and Re would double. Net effect: Qes stays the same.
so, the way you placed your driver, the vents outward is also helping in weakening of stray magnetic field too
on parallel, this may not have happened
the reason is, parallel increases the Qes, which is important fundamentally, as this Q damping is second most important after Qms and we can control it.
as said earlier Qes remain same, voltage amount gets half leads to 1/4th of distortion on two driver setup. so on 4driver that is 1/16th of one RAB
this is a great feat to be proud of. plus Impedance remain same
but the amp you need now has to be poweful or you have to design a impedance equalisation and zobel circuit on parallel with longer horn. get that thing to work on 88ohms on all freq
it can make the iem sound like a TOTL headphone, if done right
that is 4driver zero cross
so to conclude
your project has a lot of potential
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dhruvmeena96
Headphoneus Supremus
https://earphonediylabs.com/index.p...rivers-flagship-product-of-earphone-diy-labs/
amazing driver
i have one.
this is faster than BA. I mean to say, way way faster in bass department
slightly slower than SWFK, but this beast extend to 48kHz
and the measurement by them is slightly different, but it does sound like shure 1840, just more focused compared to stage performance
good thing to diy with
amazing driver
i have one.
this is faster than BA. I mean to say, way way faster in bass department
slightly slower than SWFK, but this beast extend to 48kHz
and the measurement by them is slightly different, but it does sound like shure 1840, just more focused compared to stage performance
good thing to diy with
Very nice read explaining the very basics of tuning an IEM: https://www.innerfidelity.com/content/how-balanced-armature-receiversdrivers-work
AFAIK this is just RAB-32257 with different port and solder pads locations.
Doesn't seem to have ferrofluid, so it's strange for the name to have F in there.
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dhruvmeena96
Headphoneus Supremus
It is slightly differen t in impedance curve
And Knowles did published all spec important for our convenience
I can tune it with precision compared to hit and trail.
I can smoothen out peaks without damper just because I can make a perfect circuit
Old driver didn't had that
Plus it is cheaper than RAB(way cheaper)
Fair enough.
I've got a question - Is there a way to attenuate a woofer without losing subbass extention?
CI's are just too loud!
I've got a question - Is there a way to attenuate a woofer without losing subbass extention?
CI's are just too loud!
dhruvmeena96
Headphoneus Supremus
Easy,
Add a resistor and then cross your mid range according to that
Or use a resistor attenuation circuit
Two in series, one in parallel
https://www.everythingrf.com/rf-calculators/attenuator-calculator
Simple
Well, if CI is loud for you, HODVTEC would be a nightmare then...
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Just adding a resistor and crossing over kills sub-bass extention. Is that an impedence problem? Does that attenuation circuit fix that?
And yeah, HODVTEC is... oof.
dhruvmeena96
Headphoneus Supremus
attenuation circuit lowers overall dB rather than changing the property of circuit
you will lose some, but the loss will be uniform overall.
if you need subBass extension(true level)
you can do
only CI part. It will provide you godly subBAsssssssssss
not even Sony XB90EX can reach the level of subbass extension this can
and swap the capacitor/dual resistor CI with HODVTEC. and SUBBASS goes heart rumbling
the First CI with Cap and resistor is crossed at 72.346Hz and is damped hard. Second CI is damped even harder but play full range
TWFK with full range FK is reversed so it cancel some mid bleed issues and treble FK is extreme high pass
if you go this way of tuning, you have reverse the polarity of Mid driver and cross it properly in conjunction to Dual CI
dhruvmeena96
Headphoneus Supremus
@piotrus-g Well
In Fibae Black, after seeing the images more carefully
you didnt use a traditional helmholtz resonator but a Sealed top Kienle Resoantor System(sort of resonator when sealed), For that bass boost, which you damped very specifically so that fo can be spread ou evenly instead of making a bass boost peak
well i think i am near to what you did.
damm man, if it is Kienle system, then man, you seriously did spend a lot of hours, because it is nasty to tune it(so much work, to sound naturally)
but reward is an immense soundstage(i mean seriously that thing will go bonkers on staging), Dad have a organ loaded piano(he did a diy a long time ago on some cheap wood piano) and that thing sounds grand and never ending.
He told me about the structure today, and he told me about speaker loaded organ is kienle system and when you seal the top at perfect octave, it is a tuned resonator. Well Resonator sounds less grand compared to flue organ structure, we cannot do that in iem, plus it needs some extreme paperwork and calculator.
and he told me, that he can boost specific Freq plus due to overtone can structure the bass plus boost some hefty low end on both platform
and when i told him about your project
he saw the images too(but was not able to tell), but i showed him your frequency response and the literal size of tubing inside iem i do
he said
"That guy is crazy"
well dad took his speaker tubes in comparision
but when i calculated resonator value in actual
its is easy to get a resonance f, but it is very hard to control harmonic tone or overtone(i mean very hard)
From a knowles RAF calculation
i need 2mm tube with 20mm length closed from one side aligned perpendicular to main tube, to make it act as a spring resonance at 270Hz
but that peak goes like monster, and when i use damper it becomes either too damped or not a considerable effect while my Q remains the same instead of extending on both side
by the way i don't want to boost 270Hz, that was just experiment as i was learning
but one thing do happens which is noticeable
low frequency, even boosted, goes a little far away perception, which gives a good amount of separation. i think after hearing this, i can tell why FIBAE Black was reviewed to be a huge stager
a guy even told me it is bigger than Andromeda(Head fi member)
Man, @piotrus-g your work turns an inspiration for me, and i don't know why i always get the itch to reverse engineer your work.
FIBAE 1
my solution:
I made some circuitry(take it as complex zobel and a notch filter) to flatten out impedance
FIBAE Black
my solution
Damm, i am so near but far away..............this is hard as ****(those are actual star and no abuse), perpendicular resonator(closed organ). Still dont know the dampers
and dont tell me, i dont wanna cheat...my hardwork can lead me to some new direction
@Ivan TT you can learn from this
1. Traditional Helmholtz resonator(Spring, can be used for specific tuning)
2. Concentric porous resonator(peak silencer)
3. Front loaded air gap resonator(TAEC, used for slightly smoother treble......EDGAR mid range horn)
4. Kienle Resonator System(Technically god of all the above, used in speaker loaded organ pipe, plus can be fused with any of the above, but it is hardest to tune)
Kienle Resonator System is actually simple in open pipe, but closing it changes the way how frequency moves. and iem need closing one, since opening the top means everything leaks in iem body
In Fibae Black, after seeing the images more carefully
you didnt use a traditional helmholtz resonator but a Sealed top Kienle Resoantor System(sort of resonator when sealed), For that bass boost, which you damped very specifically so that fo can be spread ou evenly instead of making a bass boost peak
well i think i am near to what you did.
damm man, if it is Kienle system, then man, you seriously did spend a lot of hours, because it is nasty to tune it(so much work, to sound naturally)
but reward is an immense soundstage(i mean seriously that thing will go bonkers on staging), Dad have a organ loaded piano(he did a diy a long time ago on some cheap wood piano) and that thing sounds grand and never ending.
He told me about the structure today, and he told me about speaker loaded organ is kienle system and when you seal the top at perfect octave, it is a tuned resonator. Well Resonator sounds less grand compared to flue organ structure, we cannot do that in iem, plus it needs some extreme paperwork and calculator.
and he told me, that he can boost specific Freq plus due to overtone can structure the bass plus boost some hefty low end on both platform
and when i told him about your project
he saw the images too(but was not able to tell), but i showed him your frequency response and the literal size of tubing inside iem i do
he said
"That guy is crazy"
well dad took his speaker tubes in comparision
but when i calculated resonator value in actual
its is easy to get a resonance f, but it is very hard to control harmonic tone or overtone(i mean very hard)
From a knowles RAF calculation
i need 2mm tube with 20mm length closed from one side aligned perpendicular to main tube, to make it act as a spring resonance at 270Hz
but that peak goes like monster, and when i use damper it becomes either too damped or not a considerable effect while my Q remains the same instead of extending on both side
by the way i don't want to boost 270Hz, that was just experiment as i was learning
but one thing do happens which is noticeable
low frequency, even boosted, goes a little far away perception, which gives a good amount of separation. i think after hearing this, i can tell why FIBAE Black was reviewed to be a huge stager
a guy even told me it is bigger than Andromeda(Head fi member)
Man, @piotrus-g your work turns an inspiration for me, and i don't know why i always get the itch to reverse engineer your work.
FIBAE 1
my solution:
I made some circuitry(take it as complex zobel and a notch filter) to flatten out impedance
FIBAE Black
my solution
Damm, i am so near but far away..............this is hard as ****(those are actual star and no abuse), perpendicular resonator(closed organ). Still dont know the dampers
and dont tell me, i dont wanna cheat...my hardwork can lead me to some new direction
@Ivan TT you can learn from this
1. Traditional Helmholtz resonator(Spring, can be used for specific tuning)
2. Concentric porous resonator(peak silencer)
3. Front loaded air gap resonator(TAEC, used for slightly smoother treble......EDGAR mid range horn)
4. Kienle Resonator System(Technically god of all the above, used in speaker loaded organ pipe, plus can be fused with any of the above, but it is hardest to tune)
Kienle Resonator System is actually simple in open pipe, but closing it changes the way how frequency moves. and iem need closing one, since opening the top means everything leaks in iem body
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After reading up on Kienle Resoantor System I don't think that's correct and I would still hold we are using Helmholtz
The Kienle seems to be positioned in front of the driver with sound outlet perpendicularly to the resonator and the speaker. In our design the speaker doesn't fire into the resonator. The resonator is parallel to the speaker and in theory perpendicular to the sound outlet.
The Kienle seems to be interesting idea to check out.
The Kienle seems to be positioned in front of the driver with sound outlet perpendicularly to the resonator and the speaker. In our design the speaker doesn't fire into the resonator. The resonator is parallel to the speaker and in theory perpendicular to the sound outlet.
The Kienle seems to be interesting idea to check out.
dhruvmeena96
Headphoneus Supremus
So it is the adjacent Helmholtz resonator...
Makes my work simpler then
But how did you get a wide Q on bass.... I am getting a peak while other freq remain same...
Well, Helmholtz resonator can still do, overtone, but elevating whole bass region seems hard for me.
I think I have to use multiple resonator ¯\_(ツ)_/¯ but then it will come out my iem and it will become something like hearing aid.
Damm....
Well, it is all about overtones, and my dad still said that this much complex tubing to achieve respectable bass boost from single driver in such a small casing is crazy work and too much time consuming for him to do for me
He gave me some formulas on Helmholtz resonator, kienle resonator and porous resonator and told me how to make them but miniaturizing them seems is very hard till now
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