DIY Custom IEMs : Part 2

[akiroz]

Quote:

Can't you just buy acrylic based resin?
It would be useful for future projects in any case.

I got my epoxy resin from my dad's lab
Not sure where to buy them.

I won't even consider Taobao (Chinese ebay) again because last time I bought some chemicals there... (For part 1)
What I See Is NOT What I Get.
 
The Polyurethane Resin's A:B Ratio is messed up (Assuming that It IS PU Resin.......)
And the Silicone Rubber type is wrong.

 

[bowei006]

Wow...borisu has a new CIEM comming
 
 
Hey Borisu, how do you know it will sound good? I'm sure a CIEM isn't just throw some Drivers that are good in there with everything nice and done and bam.. Good CIEM,
 
Doesn't specially designed drivers, their positioning, the air and room around them (even if they are armatures) and other factors affect sound?

 

[Tilpo]

Wow...borisu has a new CIEM comming


Hey Borisu, how do you know it will sound good? I'm sure a CIEM isn't just throw some Drivers that are good in there with everything nice and done and bam.. Good CIEM,

Doesn't specially designed drivers, their positioning, the air and room around them (even if they are armatures) and other factors affect sound?

Well, especially the crossover is going to be tough to get right if you have multiple drivers.

For single drivers it's not much of an issue. As long as they point roughly in the right direction they should do just fine.

 

[bowei006]

Quote:

Well, especially the crossover is going to be tough to get right if you have multiple drivers.
For single drivers it's not much of an issue. As long as they point roughly in the right direction they should do just fine.

How do you set crossover? With computer aided design, math or whatever.
 
And the drivers are already on their own palet as I can tell, are their cross overs already pre set in a sense that the bass or LF driver is set to say intercept signals of 200Hz and below and etc?

 

[Tilpo]

How do you set crossover? With computer aided design, math or whatever.

And the drivers are already on their own palet as I can tell, are their cross overs already pre set in a sense that the bass or LF driver is set to say intercept signals of 200Hz and below and etc?

?

Boris is doing a single driver build, so no crossover.


If you do want to do crossover then you'd need to get the frequency response graphs of the drivers, and precise sensitivity measurements. Then you'd need to just simulate it using a little bit of math and adjust the model until you have a desired frequency response.
Because of the small acoustic chamber you're creating, chances are that the simulations will not give perfect results. So you need to make small variations and listen by ear (and measure the FR) what's best from several designs.
Then keep tweaking until you have the desired sound.

At least, that's how I imagine it goes.


It's not impossible for a DIY'er to do, but since the crossover circuitry will be surface-mount, and because you'll require a lot of iterations before it's perfect, multiple-driver IEM's are going to be a tough one for DIY'ers.

 

[bowei006]

Quote:

?
Boris is doing a single driver build, so no crossover.
If you do want to do crossover then you'd need to get the frequency response graphs of the drivers, and precise sensitivity measurements. Then you'd need to just simulate it using a little bit of math and adjust the model until you have a desired frequency response.
Because of the small acoustic chamber you're creating, chances are that the simulations will not give perfect results. So you need to make small variations and listen by ear (and measure the FR) what's best from several designs.
Then keep tweaking until you have the desired sound.
At least, that's how I imagine it goes.
It's not impossible for a DIY'er to do, but since the crossover circuitry will be surface-mount, and because you'll require a lot of iterations before it's perfect, multiple-driver IEM's are going to be a tough one for DIY'ers.

Oh. I thought he had three drivers..nevermind.

 

[akiroz]

@bowei
Positioning doesn't really that much as far as I know.
I'm using a Dual BA driver assembly from Knowles
(1x Tweeter, 1x Woofer, 2-way crossover) All in 1 small package.
So, no it's 2 BA not 1. Just that the crossover has already been done for me.
 
 
@Tilpo 
I actually plan to design a multi-BA IEM in the near future.
Using the Knowles CL series (Sub) Woofer, WBFK series Tweeter and a midrange (or 2) I haven't decided.
The tuning will be done using a DSP crossover for high flexibility (that's what my 4-channel DAC is for 

)
Then I will build a corresponding physical one with SMT parts.

 

[Tilpo]

@bowei
Positioning doesn't really that much as far as I know.

I'm using a Dual BA driver assembly from Knowles
(1x Tweeter, 1x Woofer, 2-way crossover) All in 1 small package.
So, no it's 2 BA not 1. Just that the crossover has already been done for me.


@Tilpo 
I actually plan to design a multi-BA IEM in the near future.

Using the Knowles CL series (Sub) Woofer, WBFK series Tweeter and a midrange (or 2) I haven't decided.
The tuning will be done using a DSP crossover for high flexibility (that's what my 4-channel DAC is for  )
Then I will build a corresponding physical one with SMT parts.

One of these days I could see you go pro with this stuff, lol.

 

[akiroz]

Quote:

One of these days I could see you go pro with this stuff, lol.

Haha.
Nah, I'm just doing it for fun.
And who doesn't want low-cost CIEMs with Anime art??
 
If this project is successful, I may sell my UE11Pro,
Then make a equally good CIEM with Cash to spare 

 

[Tilpo]

Haha.
Nah, I'm just doing it for fun.
And who doesn't want low-cost CIEMs with Anime art??

If this project is successful, I may sell my UE11Pro,
Then make a equally good CIEM with Cash to spare 

Well, if you'd be able to do that then you're very lucky.


In fact, probably so lucky that I'd beg you to make one for me too, with you making a decent amount of profit.

 

[akiroz]

Quote:

Well, if you'd be able to do that then you're very lucky.

In fact, probably so lucky that I'd beg you to make one for me too, with you making a decent amount of profit.

It actually doesn't seem that hard to me.
The UE11Pros consists a Knowles CL woofer, 1 Dual Midrange and 1 Tweeter.

The CL is Knowles said to be the best woofer they have, and the WBFK is their best Tweeter.
So now I just need to find a midrange (Maybe TWFK) and figure out the tuning.
(The UE11Pros uses 2 SMT components and 2 dampers each side)
Doesn't seem hard does it?

 

[Tilpo]

It actually doesn't seem that hard to me.

The UE11Pros consists a Knowles CL woofer, 1 Dual Midrange and 1 Tweeter.


The CL is Knowles said to be the best woofer they have, and the WBFK is their best Tweeter.

So now I just need to find a midrange (Maybe TWFK) and figure out the tuning.
(The UE11Pros uses 2 SMT components and 2 dampers each side)
Doesn't seem hard does it?

I know it doesn't seem that hard, but the construction and tuning will probably be very labor insensitive (meaning it'll take quite a bit of time do to right).

 

[akiroz]

Quote:

I know it doesn't seem that hard, but the construction and tuning will probably be very labor insensitive (meaning it'll take quite a bit of time do to right).

Yeah, that's why I plan to use a DSP crossover to tune it first.
But I'll have to rely on my ears for tuning since I don't have a measurement mic. 

 

[kiteki]

Very nice b1o,
 
I'd <3 to do something like this...

 

[akiroz]

Quote:

Very nice b1o,
 
I'd <3 to do something like this...

Heyy!
I haven't seen you in a while, where have you been?
 
So far the hardest part in making a CIEM for me is the custom shell
so If you can get that made for you, the rest is quite easy.
Why not give it a try?