DIY Graphene/Graphite diaphragm condenser capsule project

[MicMaven]

Here the test results in my home made test box with one of my microphones. It is a a test box good enough to compare the capsules.in Blue the KK47 china and in purple the graphene I made. Both have that lack of basses I could hear clearly, and the graphene is more linear in high frequency: my ear was right!

Good Day Mr. Frobozz.

Stray Thought No. 3987 -- The frequency curve indicates diminished bass falls below 150 Hz. While I appreciate you may desire a full range result, I wonder whether you have produced a really good vocal or solo instrument recording microphone. In this regard, I recall the number of microphones with a switchable high pass circuit which reduces very low frequency rumble. Your capsule does this automatically. Its evenhanded management of upper low, mid, and high frequencies - especially the sharp high frequency roll-off above 10,000 Hz suggest it would be ideal for capturing vocals and mid-to-upper-range instruments such as string instruments, flutes, guitars, wind instruments, etc. It might be especially useful for computer speech recognition and communications audio which purposely/intentionally limit input to the frequency range of human speech. Not necessarily what you want, but perhaps a very useful, albeit more limited, use case? After all, some of the best inventions were produced as accidental or unintended results of trying to make something else. Um ... ahem ... any traction? James - K8JHR -

 

[Gyan]

This is a good idea. i am experimenting a way to grow real Graphene on a platic diaphragm.
Graphene is different from Graphite spray that I used on the capsule I posted opening this thread.
Graphene has atomic dimensions, but at present my test are unsuccesfull. The 6um layer does not survive the teatment. But now... time for vacation, don't you think? Thank you all for your support.

I have a collection of graphene nanoplatelet powders that were left at a former job by a polymer engineer and couldn't get myself to toss. I'll look up the specs if you are interested and can send you some samples to play around with.

 

[frobozz]

I have a collection of graphene nanoplatelet powders that were left at a former job by a polymer engineer and couldn't get myself to toss. I'll look up the specs if you are interested and can send you some samples to play around with.

Oh yes it could be interesting! Please DM me

 

[kingkorg]

This gives me some ideas.

 

[frobozz]

This gives me some ideas.

I tried growing up graphene with laser light on special 6um film, but I surrended very fast since there were too many tries to achieve a result, since the media burned every time during treatment.
This method seems more reliable, I have to investigate the price of the liquid graphene, I guess gold is cheaper
Thank you for suggestion!

 

[SubSpec]

I tried growing up graphene with laser light on special 6um film, but I surrended very fast since there were too many tries to achieve a result, since the media burned every time during treatment.
This method seems more reliable, I have to investigate the price of the liquid graphene, I guess gold is cheaper
Thank you for suggestion!

Looks like their version is €55 per 100ml, assuming it's the GXT-INK

 

[Екатерина]

Perhaps graphite film can be used, with 12 μ M in 1688

 

[Tim Campbell]

It is interesting. This idea was done by a few members almost 20 years ago and finally abandoned. Why not simply use aluminim metalized mylar from capacitors? It is cheap, plentiful and can be found in 6 micron thickness. If you need just a dot simply remove the unwanted with alcohol and a q tip or build capsules like I have done with an insulation ring surround?

 

[Екатерина]

Tin foil should also be a good choice

 

[frobozz]

It is interesting. This idea was done by a few members almost 20 years ago and finally abandoned. Why not simply use aluminim metalized mylar from capacitors? It is cheap, plentiful and can be found in 6 micron thickness. If you need just a dot simply remove the unwanted with alcohol and a q tip or build capsules like I have done with an insulation ring surround?

Do you remove metal from Mylar with simple alcohol? How do you manage to obtain an almost perfect circle (just for the aesthetic purpose)?
Btw the challenge here is using graphene or graphite
Thank you!

 

[Tim Campbell]

Well it isn't hard to figure out . Place something in the center and wipe around it. Yes alcohol can be enough with a little force but if you are building the capsule an insulator is easy.

Graphite has already been done many times and been shown inferior to metal deposition.

 

[frobozz]

Well it isn't hard to figure out . Place something in the center and wipe around it. Yes alcohol can be enough with a little force but if you are building the capsule an insulator is easy.

Graphite has already been done many times and been shown inferior to metal deposition.

I tried with spray graphite and the result wasn't so bad, but of course thickness is a problem. Graphene could be better and I will try. I searched a bit but I found only one thread speaking of using a graphene foil for a capsule but no result report. And thickness was around 20um if I remember.
Indeed, we are here to experiment and that's all the fun, isn't it?

 

[rock soderstrom]

Indeed, we are here to experiment and that's all the fun, isn't it?

+1

 

[bremusound]

Hi, i bought one of the tensioning rings from frobozz which are great!
A question about tensioning - i am trying to reskin a Neumann K89, these have membranes glued to rings. They resonate at about 1580 Hz after dismounting from the backplate. I tensioned the mylar to this frequency but after glueing the ring the frequency is of course much higher. Are there any maths to determine the frequency while tensioning?
Thanks!

 

[molke]

I tensioned the mylar to this frequency but after glueing the ring the frequency is of course much higher.

Do you mean the frequency gets higher after glueing with the same clamping diameter? Then I don’t have an explanation, but the resonance frequency should be basically inverse proportional to the clamping diameter.

 

[bremusound]

The ring glued to the membrane is smaller than the tensioning ring, see photo attached.
Will check out the online calculator, thanks!

 

[frobozz]

The ring glued to the membrane is smaller than the tensioning ring, see photo attached.
Will check out the online calculator, thanks!

Hi, are you sure you have to glue? generally the screws are enough. Could increased tension can be due to weigth of the ring, if you let it floating while fastening the screws?

 

[Sidebstudio]

Hi, i bought one of the tensioning rings from frobozz which are great!
A question about tensioning - i am trying to reskin a Neumann K89, these have membranes glued to rings. They resonate at about 1580 Hz after dismounting from the backplate. I tensioned the mylar to this frequency but after glueing the ring the frequency is of course much higher. Are there any maths to determine the frequency while tensioning?
Thanks!

Can I ask you which kind/type of glue have you used? I'm searching this detail before ruin a sputtered mylar capsule.
But I'm in same situation: I'm reskinning a neumann capsule (k103) that originally has membrane glued to front ring. But it's possibile to fix only with screws.

 

[kingkorg]

Can I ask you which kind/type of glue have you used? I'm searching this detail before ruin a sputtered mylar capsule.
But I'm in same situation: I'm reskinning a neumann capsule (k103) that originally has membrane glued to front ring. But it's possibile to fix only with screws.

Regular epoxy works great for me, but you don't have to glue it. Are you doing diaphragm sputtering yourself?

 

[bremusound]

Can I ask you which kind/type of glue have you used? I'm searching this detail before ruin a sputtered mylar capsule.
But I'm in same situation: I'm reskinning a neumann capsule (k103) that originally has membrane glued to front ring. But it's possibile to fix only with screws.

I am currently trying different kinds of cyanoacrylate with aluminized mylar since the K89 is an edge terminated capsule. Will try epoxy as well. CA hardens very fast…
Maybe you should use Loctite 770 primer for glueing non-metallized mylar.