[chinsettawong]

I'm thinking of making new stators and spacers in circular shape.  What do you think?
 

 

[spritzer]

I like those but the holes are a bit too big IMO.  Also have you ever played around with unopened spaces on the stators to provide some damping for the diaphragm? 

 

[chinsettawong]

Hi Spritzer,
 
Thanks a lot for your feedback.  I really appreciate it.  The pictures shown are not to the scale.  I holes will be 2 mm, and the stators and spacers will be 65 mm in diameter.  I intend to make them smaller to try and see how much difference in sounding they will make compared to my existing ones.  Do you think that they will be too small?
 
I used to play with a few materials for damping the back stator, but I like it better without any damping.  Do you have any suggestion?
 
Wachara C.
 
 
 

 

[spritzer]

65mm could be perfect in a good housing and with a properly sealed baffle. 
 
The size of the holes really depends on your D/S gap and really shouldn't be any larger then double the D/S gap.  For Stax that means 1mm or so given their 0.5mm D/S gap. 
 
I for one don't like to damp much but I've gone to extreme lengths to dampen some drivers which just won't behave.  That said, airdamping is IMO a very good idea as it it traps air next to the diaphragm and can stabilize it.  Most undamped electrostatic drivers have some resonance frequency (usually in the upper midrange, lower treble) and this helps to tame it.  Take a look at the picture below, that's a Stax SR-007Mk2 driver and notice the ring with no holes around the driver.  That's still part of the stator with the diaphragm beneath it but it can't output any sound.  The small Stax SR-003 portable headset goes even further where only a small part of the stators is open. 
 

 

[chinsettawong]

Hi Spritzer,
 
That's interesting information.  I really wonder if that can really do some dampening. 
 
I can change my design a little bit to unable some dampening ring as you suggested.  I'll come back with some pictures.
 
Wachara C.
 

 

[chinsettawong]

Ok, I've come back with a little modification on my previous design.  This time there is some area of stators which won't have holes.  The inner circle shows where the spacer will be placed over the stator.  What do you think?
 

 
Wachara C.
 

 

[chinsettawong]

In my opinion, the area where there is no hole actually provides the diaphragm with a more intense force.  This should enhance the driver's sensitivity.
 
Here is another version.  What do you think?
 

 
Wachara C.

 

[spritzer]

Looks good, certainly well worth the test. 

 
I would also look into earpads which seal what's next to the ear from the outside completely.  Leather is the best choice here but if you do this the driver will be far more linear and you will get more bass out of it.  Even a small port to the outside is enough to create non-linear spots in the freqeuency response. 

 

[chinsettawong]

Hi Spritzer,
 
Thanks for your inputs.  I'll probably make both the first and the last designs and compare both to see if I can hear any differences.  Because of a less open area in the last design, I think it will be more efficient.  It might also help with the bass, but shouldn't be that much. 
 
I'll come back when I have new progress.
 
Wachara C.
 
 

 

[spritzer]

With more surface area being driven then the drivers should indeed be more efficient.  Not a bad thing IMO even if we are working on amps which can swing 2000V P-P. Hell, 1600V P-P is just the minimum we use these days...

 

[chinsettawong]

I plan to cut the parts this weekend.  We'll see how it goes.
 
Wachara C.

 

[robm321]

We won't complain if you post pics of the process 

, just sayin...

 

[chinsettawong]

Hi Robm321,
 
Which process would you like to see? 

 
Wachara C.

 

[odanas]

All the proccesses! 
 

 

[chinsettawong]

I'll try to take as many pictures as I can and show you the processes. 

 
Wachara C.