How to add heavy grungy/punk aestetic noise?

[K_T]

This is a bit of a long shot, but I'm hoping someone here can guide me in the right direction.

I'm trying to the attached speckled noise effect:

I have black and white image which I've played around played around with the threshold to get some good contrasts. 

I've tried to play around with the noise filters but best noise I can come up with is too fine grained. Then I've tried the pixilate filter, which gets me a little closer but obviously very pixilated. Then I tried different combinations with halftone effects, but it becomes a bit too uniform.

Does anyone have any suggestions to how I might achieve this effect.?

 

[GarryP]

After a bit of messing around I came up with this.
I’ve attached the document which you can experiment with it’s of any use.
I’m sure someone else can come up with something better.

grunge-dots.afphoto

[K_T]

Thank you so much this is great. It's the box blur and the Voroni that makes all the differnece from what I did myself.

 

[GarryP]

You’re welcome.

I’m still not entirely happy with it – it’s not as ‘crisp’ as your sample image – but if it’s usable for what you want then that’s good.

Tip: Changing the Blend Mode of the Live Filter layers often produces surprising/interesting results, so you can try that.

[K_T]

I've been playing around with your example, If you have any suggestions to get more "crisp" specks that'll be awesome, as that would be my only comment, but sofar your result is miles ahead of my intial try.