Helmet Headphone Electronics Tutorial - Hearing Enhancement

[Crimson]

You're welcome VerdantCos !

 

[Rock Lobbster]

Used this at a con for the first time this last weekend, what a game changer. Being able to both hear people and have others hear me through the helmet made the experience so much more enjoyable and I barely had to take off my helmet!
Thanks again for the fantastic tutorial on this.

 

[Clarkusmc]

This is an interesting idea, might have to look into this so I can actually hear folks over the bucket and circulation fans

 

[Worainu]

Little late to the party but I have a couple questions, do you know what size of holes the mics needed? I'm designing the holes pre print to save post processing time and was curious on if you remembered the dimensions for this brand of headset. My other question is on the rewiring? Is it needed outside the battery converter or is the slack optional? I have the idea to use an attachment for the mic on one of the sides but for the other side The default cables will probably reach for me. (The less soldering I do the better lol I am bad). Thanks for the great guide btw.

 

[Parzival]

Little late to the party but I have a couple questions, do you know what size of holes the mics needed? I'm designing the holes pre print to save post processing time and was curious on if you remembered the dimensions for this brand of headset. My other question is on the rewiring? Is it needed outside the battery converter or is the slack optional? I have the idea to use an attachment for the mic on one of the sides but for the other side The default cables will probably reach for me. (The less soldering I do the better lol I am bad). Thanks for the great guide btw.

13/32” with a STEP drill bit worked wonders for me to drill into my girlfriends helmet. Using a standard bit on my helmet left a bit more cleanup than I would have liked, BUT not impossible by any means.
Images attached of result.

Now for the electronics you can leave it stock BUT the mic length can be an issue. I tried to keep my setup stock wired as well and it was a bit of a hassle so I did end up redoing it.

 

[N8TEBB]

do you know what size of holes the mics needed?

I bought the same headset linked above, but last time I saw crimson's helmet I noticed that our mics are completely different sizes. The manufacturer must have switched suppliers, so there's no guarantee that our mic size will be the same as the one you end up with. You'll have to buy and disassemble your headset to be sure unfortunately.

Is it needed outside the battery converter or is the slack optional? I have the idea to use an attachment for the mic on one of the sides but for the other side The default cables will probably reach for me.

It's likely necessary. I can't remember for certain which wires I extended precisely, but I do remember I tried to keep as many of them as they were. I still had to extend a few wires though. Moving the battery holder is also a good idea s make it easy to change out the batteries. I think if you keep it as it is it will put the battery holder in an inconvenient spot.

 

[NobleofDeath16]

Id also recommend at this point since the manufacturer has changes microphones a couple time, picking up this set and just using them instead of the stock ones:

Amazon.com

 

[NobleofDeath16]

Little late to the party but I have a couple questions, do you know what size of holes the mics needed? I'm designing the holes pre print to save post processing time and was curious on if you remembered the dimensions for this brand of headset. My other question is on the rewiring? Is it needed outside the battery converter or is the slack optional? I have the idea to use an attachment for the mic on one of the sides but for the other side The default cables will probably reach for me. (The less soldering I do the better lol I am bad). Thanks for the great guide btw.

Id highly recommend rewiring just to have more quality control over durability and quality connections. The set up will be in your helmet, where it is not only exposed to, well, your head, but condensation and a myriad of other factors. A full resolder will give you some control of the durability of the set up and to also space things to properly snake in your helmet and easier to hide.

Id recommend it as someone who has done +5 of this set up, you'll thank yourself later with being intimately aware of how to board and wires interact, especially if any issues crop up like Jocko03 had for example like static in one output. It also is just a really good learning experience.

If you ever wanna work side by side, I'm always happy to do a set of these start to finish in Discord in a call and be there to bounce questions off of.

 

[BlazingForge]

as someone who didn't rewire. DO THE REWIRE! my hearing system is broken inside my helmet because I didn't and man am I not fixing it cause I don't want to go in and take the whole thing out. Best to do rewire it and have it work and not break then to have it break and no longer be able to use it.

 

[OpticChief]

Communication is difficult on the con floor, so why make it harder than it has to be.

The following guide will help you take an off-the-shelf pair of ear protection and adapt them to your helmet of choice. I first saw this technique used by PapaBraus on his MK VI helmet here: 3-D Printed MK VI helmet assembly and paint.

Thanks to NobleofDeath16 for peer pressuring me to write this tutorial, proofreading, and helping me take photos.

Disclaimers: This tutorial assumes/requires a basic competency in soldering and electronics. Even so, there is a possibility of damaging the circuit in following this tutorial, so proceed at your own risk. Be sure to read and understand this tutorial fully before starting work. Please be cautious when handling any glues, circuit components, or other materials inside the headphones. They may contain or be coated with harmful chemicals. It is recommended that you wear gloves and wash your hands after handling said materials. Work in a room with adequate ventilation and use a fume extractor or respirator when soldering.

The cheap circuit in the Zohan headphones picks up a lot of EMF, so expect to occasionally hear some noise (eg. when walking near a wireless router). Additionally, anything that vibrates your helmet, like fan noise, will be picked up by the microphones. All this to say- it's not perfect but it's better than nothing.

Parts:
22AWG Stranded wire, at least two colors
Zohan Headphones: Amazon.com
Battery Holder, 2xAAA: Amazon.com

Tools:
Scissors
Small flathead screwdriver
Small Phillips screwdriver
Side cutters
Soldering Iron and solder
Solder sucker and/or solder wick
3rd hand
Wire strippers


Step 1: Disassemble the Headset
Remove the headset from the box.
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Remove the black earpads from each side. They are held in with small clips and should pop out with a light application of force. Save these for later.
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Separate the earphones from the headband. Cut a slit along the top of the headband, making sure not to cut the cable inside. The headband can be discarded.
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You should now have just the earphones connected by a black cable. Remove the battery door to get it out of the way.
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Take a small flathead screwdriver and slide it between the green plastic housing and the black plastic ring from which we removed the ear pads. Apply a gentle prying motion and they should separate. Save the black rings and foam pads, as we will use them to create the headphones for the inside of the helmet.
View attachment 330035

You should now be looking at the interior of the headphones. Remove the foam filler and discard it. With a small phillips head screwdriver, remove the speakers and the PCB (Printed Circuit Board). The electret microphones and 3.5mm jack are secured with an unidentified hot glue. Please use caution and I recommend gloves/wash your hands after handling unidentified glue. This can be peeled away, allowing the mics to be pulled out and the jack unscrewed. You will also want to remove the hot glue from around the circuit board, especially where it meets the volume knob. Side cutters can be extremely helpful for this, allowing you to use a pinch and twist motion. A flathead screwdriver can be useful as well. Be careful not to scrape or stab the PCB. Once you have removed the glue from around the PCB, it should slide out sideways. Save the knob to reuse, as the stem of the potentiometer can be difficult to turn. With your side cutters, cut away plastic to remove the cable from the plastic shell. If you haven’t already, remove the nut from the 3.5mm jack and pull it out of the shell. Cut the wire connections to the battery box.
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You should now have just the electronic “nervous system” of the headphones. If you don’t want to mess around with any custom wiring and the length of the premade wires works with your helmet you may attach the battery box and proceed to installation. Check all the wiring, especially the solder joints as they are often poorly connected and come loose during disassembly of the headphones. Resolder any broken wiring and skip to step 4. If you would like to clean u or extend the wiring, proceed to step 2.
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Cont.

This is an incredibly well-documented guide, easily one of the most thorough helmet audio writeups I’ve seen on the 405th. I had a few deeper questions that I think could help honestly myself refine my approach.

Have you noticed any meaningful difference in mic clarity or feedback when mounting closer to the visor versus further back toward the cheek/ear area? I’m curious how shell resonance and breath noise factor in long-term at crowded cons.

When tuning speaker placement, did you prioritize distance from the ear for comfort or proximity for volume/clarity? I’ve seen some builds choke audio by burying speakers too deep in padding.

Long-term, have you found industrial Velcro holds up well through heat and sweat cycles, or would you still recommend a semi-rigid mount once placement is finalized?

 

[Crimson]

Have you noticed any meaningful difference in mic clarity or feedback when mounting closer to the visor versus further back toward the cheek/ear area? I’m curious how shell resonance and breath noise factor in long-term at crowded cons.

Mic placement: I'm not sure. Physics says that the placement will have some effect but I have not perceived it. The mic location will have some effect on the stereo image and clarity, but I simply chose a location that blended in with the paintjob. As far as feedback goes, I have never experienced any with this system.

Breath noise and shell resonance: I may be misunderstanding you but I have not found the sounds of the helmet or my own breath to be a problem. HOWEVER there is a problem that occurs wherein loud volumes activate the noise reduction circuit, then people turn up the volume and expose themselves to dynamically compressed, high volume crowd noise. This, like listening to music on your headphones at high volume, can cause hearing loss over time.

When tuning speaker placement, did you prioritize distance from the ear for comfort or proximity for volume/clarity? I’ve seen some builds choke audio by burying speakers too deep in padding.

100% for comfort, works just fine.

Long-term, have you found industrial Velcro holds up well through heat and sweat cycles, or would you still recommend a semi-rigid mount once placement is finalized?

No, the Velcro solution has not proved to be durable long term. If I had swen a piece of fabric and shoo goo'd that to the foam it would have held up much better, but mine is coming apart after several years of use. It's not so much from the sweat or heat but instead from the constant putting on and taking off of the helmet.

Hope this helps.

 

[NobleofDeath16]

I wonder if one of our modeling friends like tahu505 or BlazingForge could look at the design method we have for attaching the headphones inside the helmet with a compliant mechanism that can lock/unlocks from the side of the helmet. That way it could be an easy to print alternative that would probably last long term use since it seems like most of us are finding the Velcro method has a varying use life.

 

[tahu505]

I wonder if one of our modeling friends like tahu505 or BlazingForge could look at the design method we have for attaching the headphones inside the helmet with a compliant mechanism that can lock/unlocks from the side of the helmet. That way it could be an easy to print alternative that would probably last long term use since it seems like most of us are finding the Velcro method has a varying use life.

Could probably model something. It would need to be compact to fit a variety of helmets

 

[SgtSaint]

I wonder if one of our modeling friends like tahu505 or BlazingForge could look at the design method we have for attaching the headphones inside the helmet with a compliant mechanism that can lock/unlocks from the side of the helmet. That way it could be an easy to print alternative that would probably last long term use since it seems like most of us are finding the Velcro method has a varying use life.

Just curious...
Why is the system coming in and out of a helmet so often that it's killing velcro and this need is coming up? I'm just wondering what I'm missing because it seems like a "one and done" kind of installation. Then when its all installed and working ya put in some comfort foam/helmet liner foam kit to further protect wiring etc. and its in the helmet for ever. What am I overlooking or being to simplistic about?

 

[Crimson]

Just curious...
Why is the system coming in and out of a helmet so often that it's killing velcro and this need is coming up? I'm just wondering what I'm missing because it seems like a "one and done" kind of installation. Then when its all installed and working ya put in some comfort foam/helmet liner foam kit to further protect wiring etc. and its in the helmet for ever. What am I overlooking or being to simplistic about?

I have seen some people swap the same system between multiple helmets to avoid buying two.

 

[N8TEBB]

Just curious...
Why is the system coming in and out of a helmet so often that it's killing velcro and this need is coming up? I'm just wondering what I'm missing because it seems like a "one and done" kind of installation. Then when its all installed and working ya put in some comfort foam/helmet liner foam kit to further protect wiring etc. and its in the helmet for ever. What am I overlooking or being to simplistic about?

Mine is permanently installed in the helmet, but the battery pack is located behind one of the ears so that ear piece needs to come out every time the battery needs changing. But the ear on the other side, even though it’s Velcro, was set in place a year ago and I haven’t adjusted it since.