[Aldo40]

[QUOTE = "Kulgrinda, message: 15962321, membre: 485276"]
Des idées pour ça CI low passé avec RC (50 ohms série rez + 10 uF cap parallel) a rendu le pilote si maigre? J'ai également essayé le même passe-bas pour hodvtec et le résultat était plus à ce que je m'attendais

[/CITATION]


50 ohms is a lot, tried 4.7 ohms and reversed the IC polarity to check the measurement

 

[dhruvmeena96]

Any ideas why CI low passed with RC (50 ohm rez series + 10 uF cap parallel) made the driver so lean? Also tried about the same low pass for hodvtec and result was more to what I had expected

I guess you did the connection in reverse
Looks like high pass rather than low pass

Go it. Saw that there are SMD inductors available. Found RC calculators, will try it, thank you! It appears speaker values are not taken into consideration in RC filter.

One more thing

SmD inductor have high resistance so it kinda become RLC crossover

So do check on that if you want to use inductor

And also
BA imoedance is not flat, so you might get even weird results

 

[mattmatt]

I guess you did the connection in reverse
Looks like high pass rather than low pass


One more thing

SmD inductor have high resistance so it kinda become RLC crossover

So do check on that if you want to use inductor

And also
BA imoedance is not flat, so you might get even weird results

JH uses smd inductors

 

[dhruvmeena96]

JH uses smd inductors

Custom smd inductors

 

[Kulgrinda]

I guess you did the connection in reverse
Looks like high pass rather than low pass


One more thing

SmD inductor have high resistance so it kinda become RLC crossover

So do check on that if you want to use inductor

And also
BA imoedance is not flat, so you might get even weird results

Indeed it acts like high pass, but as per theory high pass would be capacitor is series before resistor (closer to the input + wire) + resistor in parallel. I have connected CI RC low pass correctly, checked it twice.

 

[MISHKA2020]

Hey guys...
One question about glycerol. Maybe is now some new theory... How many times can glycerol be used? Except when crumbs of leftover shells accumulate...

 

[MISHKA2020]

Ok. New question... I have UE triple Fi 10's. I will put them into custom mold. Any advice, should i put dampers (red & green) on 5 and 7 mm or some mm further ? Also how long tube (2mm ID) have to be? Tnx

 

[Kulgrinda]

Hey guys...
One question about glycerol. Maybe is now some new theory... How many times can glycerol be used? Except when crumbs of leftover shells accumulate...

I use the same glycerol for over a year already, tens of shells baked in it. No flakes, no coloration as of yet.

I suggest reading Sonion documentation on IEM manufacturing (google it, pdf provided in their site), it has some good examples on tube length and effect to the sound. Also they have 3 "recipes" for IEMs, I'm going to try their 2 driver setup in upcoming month.

 

[MISHKA2020]

I use the same glycerol for over a year already, tens of shells baked in it. No flakes, no coloration as of yet.

I suggest reading Sonion documentation on IEM manufacturing (google it, pdf provided in their site), it has some good examples on tube length and effect to the sound. Also they have 3 "recipes" for IEMs, I'm going to try their 2 driver setup in upcoming month.

Thank you. I read that. I will definitely do it again because I am weak in the field of electronics. Here I came up with a little trick for “us” who don’t have 711 and similar testing devices, so the only option is our own ears! That way I will test my TripleFi 10's and color and positions of dumpers.

Procedure:
Fill the Impression Kit into a 5ml syringe. Make sure there is no air in between! When dry, remove and cut as two small rolls. Shape the edge that goes into the ear. Drill the rollers depending on the required number of holes and the thickness of the tube you use on the drivers (two tubes 3OD for my setup). I hope you find it useful. Good luck

 

[HenacanPodwell]

Hello guys! I am facing this problem frequency changes on different amp.
I have been using my Ifi nano BL iematch which is for sensitive iem and headphone as an output to my iem and to measure.
Recently I have tried using the direct output and other amp and noticed a 2-3db decreases on the low end.

Note they are from the same iem.

Only low end.
This has became a problem as driving the iem from my phone and other amp sounded bright with reduced bass, while driving the iem with my dap sony a46 and ifi iematch is warmer with more bass.
I tried 22955 with the same low pass filter 20uf 5ohm, and it has the same result as well, my mid to high does not have any rc filter
Why is this happening?And is there anyway to prevent this from happening?
Thank you very much!

Edit: I tested out the low end without any rc filter, it had the opposite result where the direct output from my ifi nano bl has about 2 db more bass.

 

[ForceMajeure]

Hello guys! I am facing this problem frequency changes on different amp.
I have been using my Ifi nano BL iematch which is for sensitive iem and headphone as an output to my iem and to measure.
Recently I have tried using the direct output and other amp and noticed a 2-3db decreases on the low end.

Note they are from the same iem.

Only low end.
This has became a problem as driving the iem from my phone and other amp sounded bright with reduced bass, while driving the iem with my dap sony a46 and ifi iematch is warmer with more bass.
I tried 22955 with the same low pass filter 20uf 5ohm, and it has the same result as well, my mid to high does not have any rc filter
Why is this happening?And is there anyway to prevent this from happening?
Thank you very much!

Edit: I tested out the low end without any rc filter, it had the opposite result where the direct output from my ifi nano bl has about 2 db more bass.

This is due to the effect of the various Output Impedances of your sources with your iem (which is BA based and has a non linear impedance has well). It's caused by the interaction between the voltage drop on the output of your source and your iem.

Since your iem has a different impedance (resistance) depending on the frequency (typical BA based iem behavior), the voltage delivered to it will change with frequency.
The voltage from your amp is shared between the output of your amp and the iem, the iem will have a different voltage drop depending on how high the source impedance is. Thus altering the iem response depending on the output impedance of your source.

If the iem had a linear impedance (usually DD based iems are more less like that) it wouldn't have mattered much what is the OI of your source, the response would have stayed the same. But here we are dealing with a BA iem that have a non linear impedance thus this is happening.

A way to alter this behavior is using a voltage divider apparatus such as the the ifi IEmatch (although iirc it still has ~2.5ohm impedance which is not ideal depending on the iem you want to use) or build such an external device yourself.

Or trying to achieve a more linear impedance designing your iem either via using lpads/voltage dividers or/and zobels and more...

That's why it's usually recommended for your source to have an output impedance <1ohm, that way the iem response will be less affected (assuming the intended response from the manufacturer was designed on such a source with a <1ohm OI. it wasn't always the case)

Some people actually like the fact that some iems can slightly change behavior with different impedance in front because it allows them to play with cable and sources to find the right "synergy"

If you want to learn more about it there is an Nwavguy post about output impedance that explains it

 

[ForceMajeure]

Actually re-reading your post it seems you might be aware of the effect of different OI on your iem. Regardless, when you add/change crossovers you also change the impedance behavior of your iem thus the change with and without an rc for the CI

If you want to dive deeper to know the behavior of your iem you need to measure it's impedance response as well and see the change when you use different crossovers

 

[HenacanPodwell]

Actually re-reading your post it seems you might be aware of the effect of different OI on your iem. Regardless, when you add/change crossovers you also change the impedance behavior of your iem thus the change with and without an rc for the CI

If you want to dive deeper to know the behavior of your iem you need to measure it's impedance response as well and see the change when you use different crossovers

I see! Thank you for the reply!
I tried adding rc filter to my mid high drivers just to test it out and see if it changes from different amp just to experiment(I dont have the tool to measure impedance yet), but its only the low end that changes.

This is becoming a problem as it sounded bright on my phone which is not what I want, I am thinking of changing the whole circuit into one without low pass rc but using only dampers.

Is this one of the reason why most brands do not use RC filter for low pass?

If you don't mind would you guide me to what does L pad and voltage divider do to BAs? I know that L pad are usually used to reduce spl but I didn't know it could change impedance as well!

Also regarding zobel I couldn't find the details of the driver for zobel calculation(22955), is there any other way to calculate it?
Thank you very much!

 

[Memej]

Hi all, I just finished reading the whole thread from the beginning respect for everyone, I found the forum after creating my first CIEM, but it's addictive wants to do another better ... I wanted to try bellsing 6 but I can't search for it anywhere...

 

[dhruvmeena96]

Hi all, I just finished reading the whole thread from the beginning respect for everyone, I found the forum after creating my first CIEM, but it's addictive wants to do another better ... I wanted to try bellsing 6 but I can't search for it anywhere...

its EOL for normal world