[wolkegeist]

Anyone has experience building shell with A-B resin? I already has the impression, but idk how to use the AB resin tho. Do they need special curing time? Please I need help

 

[Choy Wei De]

My friend somehow many to open my earphone within 2 weeks of usage? I was using nail polish top coat as glue.


Has anyone tried using this epoxy glue from AliExpress?

 

[eunice]

Anyone has experience building shell with A-B resin? I already has the impression, but idk how to use the AB resin tho. Do they need special curing time? Please I need help

AB resin does not cure via UV. I don’t think it will work as you will get a solid shell and not just thin walls.
Also please only use resin rated for skin contact, your inner ear is very sensitive.

 

[eunice]

My friend somehow many to open my earphone within 2 weeks of usage? I was using nail polish top coat as glue.
Has anyone tried using this epoxy glue from AliExpress.

I tried many different glues and had the same problem. Either the glue released a white powdery substance (most super glued do that) or it was not strong enough.

I have great success with UHU two component epoxy glue. I did not try the Ali glue you posted but I think it’s worth a shot. Things to look out for is the curing time (UHU is 5 minutes) and the resulting color. (UHU is transparent with an ever so slight yellow tint) Since epoxy glue is thicker than super glue you can see a small layer of epoxy from the side, so it’s important that it’s clear.

 

[Ivan TT]

Has anyone tried smaller dampers, I see soundlink has a variety of them?

I’m still working out how to get 3 tubes into the nozzle of a universal shell, those I have can fit up to 3 1mm ID tubes (just), so I guess I can simply run tubing all the way from drivers spouts, but not sure which dampers to buy and how to place them right...

Also not sure if smaller ID will have an effect on FR (I guess it should), so would dampers resistances stay the same or need to be adjusted for narrower tubing?

Any wisdom/experience to share please?

 

[wolkegeist]

AB resin does not cure via UV. I don’t think it will work as you will get a solid shell and not just thin walls.
Also please only use resin rated for skin contact, your inner ear is very sensitive.

I saw a video on youtube of a guy making shell with A-B resin, but it’s in German and auto translate doesn’t really help tho. I used craft-grade resin so it’s pretty skin safe. I have plan on making a negative mold to put inside when curing, so it’s just the wall having resin and the center doesn’t. Probably that’s how to do it. But the german guy just use timing and not actually make any inside mold. Like he wait till the wall is cure and then drill it out and wash off the inside of the shell. Idk how long does it take tho. Probably gonna have to try for myself.

 

[dhruvmeena96]

I saw a video on youtube of a guy making shell with A-B resin, but it’s in German and auto translate doesn’t really help tho. I used craft-grade resin so it’s pretty skin safe. I have plan on making a negative mold to put inside when curing, so it’s just the wall having resin and the center doesn’t. Probably that’s how to do it. But the german guy just use timing and not actually make any inside mold. Like he wait till the wall is cure and then drill it out and wash off the inside of the shell. Idk how long does it take tho. Probably gonna have to try for myself.

And @eunice comes to the rescue

He is from Germany

He will explain us all word to word

LoL


Well, nowadays I am working on damper system(triple stage damping)

Will update when I get a proper result

 

[mattmatt]

Yes it will probably cure. you'd have to adjust exposure time maybe.

Thank you so much.

Anyway, just a question regarding tubing:

FreqPhase has a super long tubing for it's tweeter to fix the acoustic phase right? I'm kind of confused since the speed of sound is constant, but wavelength isn't. The higher the frequency, the shorter the wavelength but how does it affect the speed of higher frequencies?

 

[eunice]

FreqPhase has a super long tubing for it's tweeter to fix the acoustic phase right? I'm kind of confused since the speed of sound is constant, but wavelength isn't. The higher the frequency, the shorter the wavelength but how does it affect the speed of higher frequencies?

Assuming you have two waves of different frequencies in the exact same phase exiting the driver spout and the tube is 2cm long. Both waves propagate at roughly the same speed and so both waves will exit the tube at the same time.

But in the amount of time that has passed while both are traveling through the tube (which is the same for both frequencies), the higher frequency will have done more oscillations. So at the exit of the tube, both might be out of phase, although they arrive at the exact same time.


Imagine this:

/^\_/^\_/^\
/\/\/\/\/\/\/\/

Same length of tube, same time for traveling, but the second (higher) frequency exits the tube at high pressure while the first (lower) frequency exits at low pressure.

If you make one tube longer:


/^\_/^\_/^\
/\/\/\/\/\/\/\/\/\

Both frequencies are in phase, but no longer arrive at the same time.

Hope that adds to your confusion

 

[Xymordos]

Hmm was designing a new 6 driver design based on my previous 4 driver design and made one that's pretty much flat. Sounds slightly warm but otherwise... very flat too.

Spoiler: Frequency Response

 

[Xymordos]

Thought this might be interesting for you guys - the Chinese forums tested the THD of three IEMS- UM Mirage, Mentor, and Beyerdynamic Xelento. Turns out the dynamic Xelento has way less distortion than the BA IEMs. The fully open mid-range driver on the Mirage has higher distortion than the stacked mids drivers on the Mentor. The 4x high driver on the Mentor seems to give it really low distortion compared to the 1 driver Mirage.

UM Mentor V3: 12BA, 4-way, 4 lows, 2 low-mids, 2 mid-highs, 4 highs, 5-bore (ends with a metal tube) with 1 bore for dB-Go module.
UM Mirage: 3D printed titanium shell, 3BA, 3-way, 1 low, 1 fully open mid, 1 high.

 

[dhruvmeena96]

Thought this might be interesting for you guys - the Chinese forums tested the THD of three IEMS- UM Mirage, Mentor, and Beyerdynamic Xelento. Turns out the dynamic Xelento has way less distortion than the BA IEMs. The fully open mid-range driver on the Mirage has higher distortion than the stacked mids drivers on the Mentor. The 4x high driver on the Mentor seems to give it really low distortion compared to the 1 driver Mirage.

UM Mentor V3: 12BA, 4-way, 4 lows, 2 low-mids, 2 mid-highs, 4 highs, 5-bore (ends with a metal tube) with 1 bore for dB-Go module.
UM Mirage: 3D printed titanium shell, 3BA, 3-way, 1 low, 1 fully open mid, 1 high.

BA distorts more

i have been working on this method for a while to reduce BA distortion

A BA enclosure is made of High magnetic permeability Metal alloy(80Ni15Fe5Mo), which permeates good but has issue on magnetic saturation, this leads to magnetic flux leak and less accurate motor movement,

Beyer Tesla driver has 1.5Tesla magnetic force for round motor, which means they try to trap and direct magnetic flux mostly to coil. Plus in round speaker, magnet surround the coil properly, which can lead to highly accurate motor movement, leading to less distortion

for knowledge, Sennhieser IE80S magnet is 0.14Tesla

 

[Xymordos]

BA distorts more

i have been working on this method for a while to reduce BA distortion

A BA enclosure is made of High magnetic permeability Metal alloy(80Ni15Fe5Mo), which permeates good but has issue on magnetic saturation, this leads to magnetic flux leak and less accurate motor movement,

Beyer Tesla driver has 1.5Tesla magnetic force for round motor, which means they try to trap and direct magnetic flux mostly to coil. Plus in round speaker, magnet surround the coil properly, which can lead to highly accurate motor movement, leading to less distortion

for knowledge, Sennhieser IE80S magnet is 0.14Tesla

Interesting, is stacking drivers the easiest way to reduce distortion?

By the way, I used some Chinese drivers (not Bellsing, not sure what the actual name of the company is actually...) in the new design and they did sound quite good. One was the Chinese SWFK31736 and another they called the dual ED29689, but to me the drivers look more like the Sonion 2389D.

 

[dhruvmeena96]

Interesting, is stacking drivers the easiest way to reduce distortion?

By the way, I used some Chinese drivers (not Bellsing, not sure what the actual name of the company is actually...) in the new design and they did sound quite good. One was the Chinese SWFK31736 and another they called the dual ED29689, but to me the drivers look more like the Sonion 2389D.

Stacking driver is best way to reduce distortion. Or shielding BA with steel tape.(stacking drivers in series parallel is best though).

Dont know about SWFK, but that ED was Sonion 2389D. That dual ED needs a good 25ohm resistor and a green + grey damping to sound slightly aggressive ED.

 

[Ivan TT]

By the way, I used some Chinese drivers (not Bellsing, not sure what the actual name of the company is actually...) in the new design and they did sound quite good. One was the Chinese SWFK31736 and another they called the dual ED29689, but to me the drivers look more like the Sonion 2389D.

I was just reading your post from way back when you mentioned you have them...
Is it the same outfit that makes dual RAB, single spout?
https://item.taobao.com/item.htm?id=569062783217