While volunteering my skills for a non-classical recording, a friend's friend scratched stuff off his guitar and then blew it pretty hard directly at my MK 5s, which were just a few inches away. How do I know if they're ruined and what do I do?

EDIT: Schoeps MK 5 matched pair.

The MOTU usb interfaces? I seriously doubt any harm was done..

Schoeps MK 5.

It's 35 euro to send capsules in to be cleaned at Schoeps.
There is probably nothing at all wrong with your mics. Just blow some compressed air to clean out any dust.

Schoeps gives you all the resources right here
https://schoeps.de/en/support-servic...%20held%20down.

And you told you friend to be more aware of his surroundings, right? Like parking your grocery trolley in the middle of the aisle, or talking loud into your phone in a restaurant?

D.

Do NOT blow compressed air into the front of your (or any other) mics! Compressed air can be used to clean the back (contacts) side of the capsules, but dust wouldn't likely have gotten in there.

The mesh covering the diaphragms is likely to stop most dust from getting to them from this single incident.

If a little dust got in there, it wouldn't usually harm anything, but it can help trap a little moisture if used in a humid environment; even then, they would just need time to dry out (Schoeps say about half hour at room temp).
https://schoeps.de/en/support-service/service.html

That service rate is super cheap!

Blowing compressed air directly at the diaphragm seems risky. I would worry about the high pressure causing damage. Schoeps makes it clear that they are only talking about cleaning the contact plate this way:
I would tell your friend's friend that if your mic was damaged, he will be paying the service fee. Your finely made instruments should be treated with the same care and respect as his.

Blowing compressed air on a microphone diaphragm equals an assassination attempt.

Not even a fake Neumann U87 deserves it . . like the one in the last photo here from this ?experienced? tech:

https://plasmamusic.com/microphone-capsule-cleaning

"What do I do?"
Terminate. With extreme prejudice. They do not deserve to live.

And if you have the time, send back to Schoeps for a wash and brush up. I recently took down the X/Y in my chapel and the layer of dust was about 2cm! That's from a year of hanging there.

I submit for your consideration the opening 30 seconds of...

https://www.youtube.com/watch?v=ufpe...=2&pp=iAQB8AUB

Ah yes, my dusty u87.

The biggest secret in recording is the thing in front of the mic between the "performer" and the nice German mic.

It is there to protect the mic from the fools that attack it.

Most people think it has something to do with the sound.

They are incorrect.

I had the same reaction to watching that as when someone puts a drink on a piano. Rage.

Or duct tape to a piano lid (actual Gaffer's tape is bad enough).

That's when you call in the Finnish snipers.

Seriously, I just got a pair of BLM mounts for my DPA 4061s, and they talk about taping them to the underside of a piano lid. I know that's a technique ages old, but it would never do it for fear of marring the finish.

Isn't 'klang' the literal sound made by a BLM falling onto the piano strings when the duct tape fails....?

Also incorrect is believing that a simple bit of woven mesh will protect the mic diaphragm from cigarette smoke's tars and oils

Hence the classifieds ad for mics 'only used in a smoke free studio' .....

By comparison, the OP's dilemma with a minute quantity of dry dust blown into the proximity of a Schoeps mic could be simply solved by holding it outside on a dry windy day. That air movement alone will displace any settled dust...no need for (potentially) damaging compressed air.

Funnily enough I was just stood outside having a smoke and cannot remember the last time I saw anyone smoking in a studio, let alone a singer.

I'm guessing mid to late 90's.

Of course in ones own facility some blaze like there's no tomorrow.

Depends on the music.

And the amount of times I have gone off to buy tapestry hoops and ladies tights (pantyhose) to make a shield...

I wonder with the rise in vaping, if that stuff is potentially more damaging to microphones or other equipment? I'm thinking of the oils in the vape liquid depositing on surfaces.

The kids are adopting it in droves, so the longitudinal biological data generation process is underway already….don’t wait for the analysis and conclusions that are yet a few years off, prevent your mics from exposure to it NOW

I’m sure vape fluid aerosol is not a benign cocktail…for either lungs or mic diaphragms

forget tubes and transformers, light up a cigarette or joint!

seriously now: in earlier years, i had bought quite a few vintage tube ldc's which stank like the plague (well, like ashtrays), mainly from radio studios - they were ridiculously cheap, even if they had to be cleaned and the capsule replaced (which was still much cheaper than buying them new)... - the effect was a bit like putting on completely new strings!

anyway, before sending mics back to the manufacturer, put pink noise on your monitors, tweak eq until your measurement mic reads flat; then compare to your dut - i do this quite regularly (to see how my mics fare and to pair them for stereo application) and can report that my schoeps have held up extremely well, despite all the use and abuse!

Thanks to all for the supportive answers, and especially for the very rational suggestion just to measure them. I'll do that!