[ForceMajeure]

  Hey, if anyone is interested in the new Knowles GV, the Mc.Ear Onlineshop sells them for about 80€ here in Germany. I've got mine a few days ago, but unfortunately still could not measure what values the two SMD components have, without desolder them. Is it possible to meassure them incircuit or distort the drivers the measurement?  Now I'm thinking about what Dampers I should use. I think without Dampers the HODVTEC are used fullrange, because only the two FK drivers have a Condensator as higpass. Without dampers the GV have significantly too much heights.
 
Edit: I think, the two SMD components are Resistors. I managed to meassure the left one to 62ohm and the right one to 48ohm. Did that make any sense? I always thought, capacitores in row are used on the high drivers as highpass. But after further measurements i am pretty confident, that on all 4 drivers the negativ side is wired directly parallel and on the positiv side the the  HODVTEC is wired directly and the twfk with the two resistors.

 
These 2 components looks like capacitors to me.
Both drivers btw have different nomenclature than the usual HODVTEC and twfk.

 
32838 for the HODVTEC and 31129 for the twfk.
 
 
BTW the price ~80eur for them in the Mc.Ear Onlineshop  is for a pair?
I see that they don't have them in stock and they will be available on the 4th of April.

 

[Julianus]

Yeah, from the appereance i also thought that the 2 components are capacitors, but i could'n get any reading from my meassurement device in capacitor mode, and stable ohm values in resitor mode measured directly at the 2 contacts of the smd components.
I also saw the same different numbers on the drivers, even if the small one is very hard to read without a microscope.
Btw i measuered the resistence of the 2 small driveres to 27ohm for the left and 13ohm for the right one. That matches the twfk data sheet wich mentions:" DC Resistance: 25ohm +-10% /  25ohm FK, 12.5ohm wbfk".
 
80€ for one Driver. But i think its a fair price, because at digikey its 65€ for an HODVTEC+TWFK. I have telephoned with the owner and he mentioned that the drivers are probably earlier available and 4th of April is the last possible date.

 

[piotrus-g]

you won't be able to measure caps as long as they are connected to driver

 

[Julianus]

damit, i see now what you mean. I dont know how i could be so stupid, that i didnt see that i measuered the dc resistances from 3 speakers in parallel. Is there a way to measure the caps without desoldering? On a PCB my SMD solderskills are good, but i dont know if i could resolder them on the recivers with litz wire soldered directly to the caps like they are atm.

 

[ForceMajeure]

  damit, i see now what you mean. I dont know how i could be so stupid, that i didnt see that i measuered the dc resistances from 3 speakers in parallel. Is there a way to measure the caps without desoldering? On a PCB my SMD solderskills are good, but i dont know if i could resolder them on the recivers with litz wire soldered directly to the caps like they are atm.

You can't measure capacitance without desoldering them.
Balanced armatures have their own capacitance so it will mess the measurements.
You could desolder and solder them back rather easily but it depends on your skills. 

 

[ziixtreme]

Try to make my first IEM, got CI-22955 and ED-29689 on the way. And I have a on hand ED-30761 and WBFK-30095, can you suggest a crossover for this configuration (CI + ED + WBFK) thanks!

CI-22955 10 ohm red damper, ED29689 3.3uF green damper, WBFK-30095 0.47 or 0.22 no damper. You can try this. Make 3 bores

 

[SVTong]

I'm trying to make a very small CIEM for my wife and I don't have enough room to run dual tubes for the GK unit.  Does anyone have any advice on what damper I should be using for a single-tube GK?  She would like the sound to be slightly V-shaped.

 

[MOFiddler]

Fotoplast S IO:
 
From reading the forums, I am aware of two US vendors that will sell direct to CIEM builders/hobbyists.  It looks like 100g is the smallest quantity available for the shell forming material.  I measured this out by volume and it's just under 1/2 a cup.  Can someone please share how many shells you are likely to get from this amount of Fotoplast?  Obviously assuming I don't completely cure an entire shell or more in my learning process.  
 
Investment Material:
 
I believe one vendor will sell this by the pound.  I understand it is reusable.  I'm just wondering how long a pound should last.

 

[Bad Username]

[COLOR=FF0000]Fotoplast S IO:[/COLOR]

From reading the forums, I am aware of two US vendors that will sell direct to CIEM builders/hobbyists.  It looks like 100g is the smallest quantity available for the shell forming material.  I measured this out by volume and it's just under 1/2 a cup.  Can someone please share how many shells you are likely to get from this amount of Fotoplast?  Obviously assuming I don't completely cure an entire shell or more in my learning process.  

[COLOR=FF0000]Investment Material:[/COLOR]

I believe one vendor will sell this by the pound.  I understand it is reusable.  I'm just wondering how long a pound should last.

Around 5-6 pairs of shells, give or take depending on how thick you make them and how much you waste. Also, you need to fill the entire negative mold when curing so you'll need enough left over to do that.

Assuming you are using hydrocolloid investment material, they generally say melt 6 times max. But if you add a bit of water when it starts to dry out you might be able to use it a bit more, however it does discolour after a few melts.

 

[jbr1971]

  Fotoplast S IO:
 
From reading the forums, I am aware of two US vendors that will sell direct to CIEM builders/hobbyists.  It looks like 100g is the smallest quantity available for the shell forming material.  I measured this out by volume and it's just under 1/2 a cup.  Can someone please share how many shells you are likely to get from this amount of Fotoplast?  Obviously assuming I don't completely cure an entire shell or more in my learning process.  
 
Investment Material:
 
I believe one vendor will sell this by the pound.  I understand it is reusable.  I'm just wondering how long a pound should last.

 
I have made 10-12 pairs of shells with mine (estimating from bad memory, I did not keep count). I am just coming to the end of my supply now.
 
I bought 1 lb of clear ballistics gel and have only used around half of it. I have made 3 sets (pairs) of molds so far. It is reusable, but after I have made shells in a mold I do not melt them back down for reuse because of "contamination". With that much gel I do not need to worry about reusing.

 

[Shilohsjustice]

So I spent the majority of the night working with the HODVTEC and have some results. I tested on my rig but do not have graphs to post as I am tired and have to work in the morning.

What I noticed with no resistor and yellow damper, the HODVTEC is very thunderous and is putting out too much pressure to be comfortable for me.

From 10ohm - 30ohm resistance, sound cleans and bass drops significantly losing and shifts from thunderous to clean mud.

When I removed the damper on those ranges I found the sound signature was decent.

I removed the damper and tested between 30ohm - 70ohm resistance. To my surprise the 50ohm - 70ohm had the best detailed bass maintaining a nice sound and to my ears the 68ohm sounded the best. I plan on testing tomorrow with the SWFK as well as with a TWFK.

So far I think 68ohm resistor gets me what I want in the HODVTEC.

This was tested in a universal shell with a horn style tip, NO faceplate attached paired with a TWFK with a .47 cap.

 

[Xymordos]

So I spent the majority of the night working with the HODVTEC and have some results. I tested on my rig but do not have graphs to post as I am tired and have to work in the morning.

What I noticed with no resistor and yellow damper, the HODVTEC is very thunderous and is putting out too much pressure to be comfortable for me.

From 10ohm - 30ohm resistance, sound cleans and bass drops significantly losing and shifts from thunderous to clean mud.

When I removed the damper on those ranges I found the sound signature was decent.

I removed the damper and tested between 30ohm - 70ohm resistance. To my surprise the 50ohm - 70ohm had the best detailed bass maintaining a nice sound and to my ears the 68ohm sounded the best. I plan on testing tomorrow with the SWFK as well as with a TWFK.

So far I think 68ohm resistor gets me what I want in the HODVTEC.

This was tested in a universal shell with a horn style tip, NO faceplate attached paired with a TWFK with a .47 cap.

 
Were you able to get rid of the ~1kHz peak for the HODVTEC using crossovers? That peak is worse than the CI22955.

 

[ForceMajeure]

So I spent the majority of the night working with the HODVTEC and have some results. I tested on my rig but do not have graphs to post as I am tired and have to work in the morning.

What I noticed with no resistor and yellow damper, the HODVTEC is very thunderous and is putting out too much pressure to be comfortable for me.

From 10ohm - 30ohm resistance, sound cleans and bass drops significantly losing and shifts from thunderous to clean mud.

When I removed the damper on those ranges I found the sound signature was decent.

I removed the damper and tested between 30ohm - 70ohm resistance. To my surprise the 50ohm - 70ohm had the best detailed bass maintaining a nice sound and to my ears the 68ohm sounded the best. I plan on testing tomorrow with the SWFK as well as with a TWFK.

So far I think 68ohm resistor gets me what I want in the HODVTEC.

This was tested in a universal shell with a horn style tip, NO faceplate attached paired with a TWFK with a .47 cap.

You should try to play with blocking the vents.
Block 2 on one side with tape and start obscuring the other 2 with various materials/opening size. If I am not mistaken Luke published some graph of the hodvtec blocked and not blocked on the veritas.

 

[ForceMajeure]

Found it
https://diyearphone.com/pages/armature-measurements
 
in the bottom page.
 

 

[ForceMajeure]

   
Were you able to get rid of the ~1kHz peak for the HODVTEC using crossovers? That peak is worse than the CI22955.

I think only the yellow damper might get rid of that 1khz peak to a certain degree. You could try and see if using 2 yellow dampers in series (in the same tube) does the trick.
Having a low pass filter is probably more aggressive but effective.