[dhruvmeena96]

I want to thank everyone, because I learned a lot from you, and today I want to share, a measuring instrument that I created myself, an EMI meter, I hope to help everyone, just as you help me, I use the Smaart program and capito to sound with Pink Noise, with him I have a very good dedication, I want to thank #eunice for the tips that were through them that I could mount my meter, I still need the help of my friends, because I have a lot to learn from you

It feels like a Knowles standard measuring unit

Well done bro.....so now we got a homemade mic as per our calibrations..

Nice

Design is ready.

Finale 1

28mm tubing dampens the 6kHz of 7mm tubing. But due to long structure damping, the effect of damping decreases...so it is like slight damping filter, to the exact need.

The 56mm tubing targets the 3kHz peak. This makes the 3Hz more tame(long tube and smaller ID rolls off, which make the 3kHz strength lower than main tube, which controls the ability to cancel, so it act as a damper within it self.

Twin resonator is used for mixing phases, muffling peaks and creating a decay(natural echo artificially). Plus it helps in variable insertion depth in universal IEM, as it averages the peaks into smaller single broad peak.

Finally RAB-p famous horn structure

No dampers....

Parallel with zobel

RAB32063.



Why I am using closed BA. Because this much of tubing and structure if coupled with bass can lead to bass overhaul.

I want a straight line response with rising treble after 9kHz in BA.

I was late at posting, as I got blackening of gums due to heavy metal tartar build up(old medicine poison coming up....really old medicine when I was admitted).

Design is ready, did the simulation

Now its turn to make it real


Well I have patented it.
Can use for Homemade IEM, but please dont manufacture it.

It is for science purposes only and for understanding and education purposes

And I am a solo guy right now....so I can post anything for now...no company obligation

 

[eunice]

Nice of you, thanks for sharing. Tell us how it sounds.

If anyone interested: I had that plopping sound again on the FED. Turns out it is the flux paste in the vent hole causing it! Just touched it with a toothpick so the hole is clear and the plopping sound went away.

Also a big heads-up to everyone using the ED-30761: It has a vent hole that is so small that it is not visible by eye. At least I can't see it without magnification. But it is there and must not be covered. (See datasheet for exact location). Doesn't help that the ED-30761 datasheet is hard to find, but soundlink has the relevant parts in the product description.

 

[dhruvmeena96]

Nice of you, thanks for sharing. Tell us how it sounds.

If anyone interested: I had that plopping sound again on the FED. Turns out it is the flux paste in the vent hole causing it! Just touched it with a toothpick so the hole is clear and the plopping sound went away.

Also a big heads-up to everyone using the ED-30761: It has a vent hole that is so small that it is not visible by eye. At least I can't see it without magnification. But it is there and must not be covered. (See datasheet for exact location). Doesn't help that the ED-30761 datasheet is hard to find, but soundlink has the relevant parts in the product description.

Hahahaha. ... Hahahaga

Bad flux day
Bad flux...but its okay

It will sound something like Audeze headphones according to simulated graph.

Something like LCD2 classic
Dark velvety, grand life-like near vocals, and crazy stage
Image is compromised
Details are preserved

Total audiophile, not meant for mixing and mastering like Finale 2 and Finale 3

Finale 2 is neutral

Finale 3 takes best of both

But who knows, ears are better judge.

 

[RAFAEL DOUGLAS MARTINS]

Hi everyone, I am doing some tests and I would like the help of you, I am doing the joining of two drivers, the yellow one and a driver and the green and another driver, these measures were made separately

the frequency where it is circled in red is having the same frequency that they intersect, I am not reversing the polarity of the drivers

so when I put the two drivers together and do the measurement where it is circled in red is a very big hole, you can help me because this is happening, and how to solve it

Why is this happening? , the bass driver I'm using the low pass RC circuit and the other I'm not using anything

more independent of the low pass RC circuit happens the same way, and just taking frequency crossing or equalityat any point of two driver gets this hole

 

[eunice]

This is a phase issue. So if two drivers with the same frequency are out of phase, they cancel each other out.

 

[RAFAEL DOUGLAS MARTINS]

how to solve this?

 

[eunice]

how to solve this?

Short (non-helping) answer: adjust tubing, change RC filter or wire one of the drivers in reverse.

Long answer, not knowing your background I try to start from scratch. Imagine a sound wave as alternating high and low air pressure regions traveling through the inside of the tubes. If two drivers create the same frequency at the same volume and at the same time and both soundwaves travel through the same tubes (same length, diameter and so on) at the end of the tubes the soundwaves will be in phase. That means if you have high pressure region exiting one tube you will also have a high pressure region exiting the other tube. Both high pressure regions will add up.
The result is the sound of both drivers is twice as loud as one driver.

If a high pressure region arrives at the end of one tube while there is a low pressure region at the end of other tube at the same time, the two drivers cancel out. The result is the sound of both drivers together is silence, even though both drivers are playing.

On the electrical side you can flip the phase by reversing polarity (180 degree phase shift for every frequency), and phase is influenced by RC filters. RC filters have no phase shift for frequencies they let pass and approach 90degree shift towards the block band. Other things also influence phase like the inductance of the coil in the driver you are using.

On the acoustical side the phase is influenced by the length the signal travels (the phase shift depends on the frequency!) and other factors like resonators, dampers, horns and so on. There is tons of material to be found for speaker enclosures and very little about IEMs. But you get an idea.

Next the air pressure at the nozzle of the drivers influences the electrical impedance of the driver and therefore there is a feedback of the acoustical properties back into the electrical properties of the IEM

So how to solve?

Some use complex and expensive physics simulation software to calculate the phase ( @dhruvmeena96 for example) others use trial & error and again others try to build existing recipes from this thread to get a feeling for what can be done and what sounds good. That’s where I am at. I built 20 different CIEM and still don’t feel like trying my own designs.

Welcome at the entrance of a very very deep rabbit hole.

 

[Lucas Taboada]

I have a multimeter that can measure capacitance to 1% accuracy and those 10% tolerance 0805 4.7uF ceramic caps. They are cheap and easily range from 4.5uF to 4.9uF.

I measured a bunch of them and sorted them according to their real value. That way I know I have similar values for left/right and also access to 4.6uF caps.

Do you know if there's any type of capacitor that are more accurate and don't need this process of measuring it?

 

[Lucas Taboada]

To everyone who uses 2pin connectors, how do you cut your shells to fit the connector? I don't really like cutting it by hand with dremel, I think it is very imprecise.

---

@dhruvmeena96 do you have your designs organized somewhere? it is becoming very difficult to find it here in the thread, and knowing which one is more recent/better etc... If you don't, I think it would be awesome if we could make a document with specified design recipes that we like from here.

---

I'm still searching for a good universal shell to prototype that fits at least 2 large tubes and is easy to assemble and disassemble, to make some changes and listen, any tips

 

[dhruvmeena96]

To everyone who uses 2pin connectors, how do you cut your shells to fit the connector? I don't really like cutting it by hand with dremel, I think it is very imprecise.

---

@dhruvmeena96 do you have your designs organized somewhere? it is becoming very difficult to find it here in the thread, and knowing which one is more recent/better etc... If you don't, I think it would be awesome if we could make a document with specified design recipes that we like from here.

---

I'm still searching for a good universal shell to prototype that fits at least 2 large tubes and is easy to assemble and disassemble, to make some changes and listen, any tips

Yes I have it in my copy

And you can find MASM on google image search. It, by mistake became one of the searched thing.

I will post everything on wikia soon though

 

[eunice]

Do you know if there's any type of capacitor that are more accurate and don't need this process of measuring it?

The small SMD ceramics with 1uF - 4.7uF all have 10% AFAIK. On mouser you can easily search for tolerances.

But for Zobel, 10% on the caps might be good enough anyways and no need for measuring.

 

[dhruvmeena96]

I am going to upload a better understandable and approachable schematic

Since my mouth is not paining me that much

And I am ditching dual RAB for triple RAB32063 for ease of use and better tuning capabilities and formulaes

Since I can control individual 2 point of frequency

 

[MuZo2]

Is TIA open BA proprietary? havent seen anyone else using open BA..

 

[dhruvmeena96]

Is TIA open BA proprietary? havent seen anyone else using open BA..

Unique melody new IEM

 

[MuZo2]

@dhruvmeena96 what are your thoughs on tubes and resonance?