Headphone cleaning. Disperse the dirt and detritus, or let it get crusty?

Some of you may know from a couple of threads I have previously posted to both here and on head-fi that I'm probably the biggest Sennheiser HD5** series fanboy and this post relates more or less specifically, but not exclusively to these models.
I've literally lost count of how many different sets I have now as some have been fully refurbed, while some are languishing disassembled in boxes waiting to be refurbed. There's about 23/24 sets from different models in the range.

In any case, everytime I receive a set I usually give it a quick once over and test to make sure they work and there aren't any critical issues such as cracked plastic components etc. Then they either go straight to a process of decontamination, cleaning and final refurb or they go into a box for later. It depends how much time I have and if I'm feeling up to getting in amongst all the years-worth of (other people's) built up grime and grit.

I wonder how many of you headphone junkies take time to consider how much dirt accumulates in your favourite pair of headphones or whether you have ever looked at the ports of your IEM's through a magnifying glass?
You may be surprised and disgusted in equal measures to see what's actually lurking behind tips and bits of foam and within the nooks and crannies of a headphone chassis!

The disassembly and decontamination part of a 2nd hand pair of headphones is usually the trickiest, particularly with the HD5** series as even though most parts are user-replaceable/serviceable there are still things that can go wrong; such as cracking the ends of the headband when removing the yokes, or fatally damaging the tiny condcutor wires of the speaker drivers. If one of those breaks it's game over!
Bits of detritus can also spring out at you when plastic components are flexed/released, so it's also advisable to wear some form of PPE - a mask, glasses and latex gloves in order to preserve your own health and avoid ingesting crud and dust. Yuk.

Disassembly:
Time to separate those grimy plastic bits from the foam bits. The foam bits go in the bin and the plastic bits go into a basin of hot soapy water to soak while the speaker baffle chassis and speaker drivers get treated to a brush and IPA clean.




I wanted to highlight the following step in this thread as it applies not only to the HD5** series, but also the HD6** series too. As most of you probably know already the black baffle/driver chassis which makes up each headphone cup are totally interchangeable between each range and model as they are the same physical shape/dimensions.
A 'deep clean' necessitates removing the speaker driver from the baffle chassis and this is the trickiest procedure out of the whole process.

The speaker drivers are held in place by 4 tabs that need to be pushed back in order to release the driver from the chassis. My own method is to use either a plastic spudger to push the tabs back or just my fingers. You don't want to use anything metal during this procedure as you increase the risk of total damage if something goes wrong.



When removing the speaker driver it is absolutely critical that you avoid touching or snagging the 2 tiny conductor wires that lead to the speaker from the plug socket. These are incredibly fragile and once damaged and no matter how much of an expert solderer you think you might be, you CANNOT repair them. Ask me how I know this.
Tyll Hertsens also knows about this too. lol



As you can see in the photo above, those wires are just tiny. Thinner than a human hair apparently.
Notice how the wires of the driver on the left looks fine. Even though they are crossed and are possibly touching each other they are enamelled and therefore electrically isolated. Ideally they should be physically separated to avoid inductance. The driver on the right however has one of the wires situated outside the wire channel and if I was to replace this in the chassis this way it would probably break. So use a suitable instrument to re-situate the wire inside the channel before replacing.



It's also highly adviseable to not mess around with the springs with which the pins of the headphone cable connectors interface this as the risk of damage the wires is also high. My advice would be to buy a new aftermarket cable (perhaps from *kof* Chris Cables for example) which use connectors with pins machined to the outer limits of the fit tolerance dimension.


Cleaning.
The baffle chassis can be brushed out then cleaned with IPA and a cotton bud once the speaker drivers are carefully removed. Just avoid touching the paper (or metal) baffles as these are also very delicate components. A fine sable brush comes in very handy to remove dust.

The image below shows the front face of the speaker drivers and you can see just how much dust and grit has built up over the years. It's important to remove this as it can cause unwanted resonance/vibration. Hold the driver in an inverted position and use a sable brush to very gently agitate the dust so that it drop away from the surfaces. This is obvioulsy easier said than done but using a holder and a louplamp can help and again it's imperative to avoid touching the conductor wires.

Before


After.

If there are any stubborn bits of dust that you cannot remove with the sable brush then just stop and leave them. The risk of damaging or denting the delicate translucent polymer material is higher than the risk that the particles will cause an audible issue, so leave them be!
If you do drop a clanger and end up denting the polymer you can reverse the dent by gently blowing though the rear face of the driver until the dent disappears.
It looks like there are dents in the drivers in the photo but it's actually just a reflection of the LED ring light in my loup-lamp.

Once carefully reassembled the baffle chassis can be re-inserted into the outer nacelle / speaker cup ready for attaching new foam pieces.


Attaching the foam pieces can also be tricky and has a risk that you can damage the delicate baffle material if you press on the wrong places.
You will be able to easily see where the foams clip to the chassis and pressing on the 4 appropriate areas instead of randonly trying to press the foams into place is the correct method.


Finished and ready to go!


When was the last time you cleaned your cans?
Got a particular method or regimen?

 

Nice thread, Chris.

Personally, I go full cavewoman with my HD650s and just completely dismantle everything and drop all the modular pieces (MINUS THE DRIVERS) in batches into an ultrasonic cleaner filled with warm water and a couple tabs of Efferdent. This has never failed to restore even my nastiest gunk. I haven't preformed this method with the black silk chassis but with the silver stuff it does just fine, I just bang the chassis against a wall afterwards to remove the excess water and then point a fan at it, presto, baby. Just like new.

Obviously I do not drop the drivers in water, but I do clean them carefully with iso and a cotton swab, another trick that I haven't seen mentioned much is to utilize a hot air rework gun on the driver membrane to get rid of any dents... 130 degrees, about a 2 on the blower dial... Go in circles with a medium gauge head around the membrane, staying aware of the heat... A ton of people recommend blowing into the back of it but that doesn't always do the trick, you're left with little dents around the edge sometimes... but, by heating the membrane CAREFULLY (don't be an idiot) with the gun, the plastic goes back to its original shape pretty easily with no hint it ever had an issue, had a few membranes that were seemingly fucked and couldn't get their bubble back, but the rework restored them almost instantly, takes no time at all.

But yeh, ultrasonic cleaner, a fan, and some hot air... soft toothbrush with some iso for the grills if you got some real gunk?

That's about it, never had an issue.

Keep it clean.