So I bought the 37mm lenses and 5pcs 60mm F180 lenses (whereby I need 4 per eye) and thought of what else needs my attention whilst waiting for that long AliExpress delivery time.

For the sound system, I first looked to see if I could just take a headphone I liked out of the thousands probably out there by now. There's so many out there that I asked myself the question "What kind of headphone would I like to try?". 

So I watched a few videos talking about things like trebble and bass response and soundstage and imaging and I came to the conclusion that I wasn't actually interested in better sound quality but an improved headphone experience. I wanted to try:

• Open ear (not sealed) headphones or sealed headphones that sent a slow stream of air over the ear.
• Multiple speaker drivers per ear. I've seen it a lot in the enthusiast earphone space (I assume to get a wide frequency response from multiple small drivers) but I'm more interested in directional audio (which is what multiple drivers in headphones do).
• "Dynamic spatial audio" is what I think the term is for being able to hear sounds omnidirectionally and not just a 360 degree plane such as 7.1 surround sound. 
  • This is important for sound TyMist virtual monitors. If there's a video coming from the top virtual monitor and I'm looking at the centre virtual monitor, I want the video to sound like it's still originating from above my head (where the virtual monitor should be) instead of straight forward. 
  • Even the description for dynamic spacial audio doesn't sound 100% like what I want, because I also want it to be able to take translational movement into account. It doesn't need to rival VR tracking, but being able to move my head 30cm in any direction without head rotation and things sound like they're locked to a physical point in space.

Well I'm assuming my headphone choices dropped to 0 like a pallet of bricks. That's fine because most HUD / AR / VR devices come bundled with their own audio solution anyway. It would just have been nice not to have to invent everything here.

Holding up my portable monitor and moving the speaker grill around my ear, I came to the conclusion that I certainly needed 3D audio for TyMist and have decided to opt for 4 speaker directions instead of 3 for a bit more pinpoint accuracy and because I can arrange them in a diamond-square. I'm currently printing this initial concept of an earcup:

The top 45mm thing is where I could put a 4010 blower fan to try out the air stream if I take this concept further.

The speakers will be facing inwards, towards the ear. Since most sounds would probably be coming from infront of me, I think having 2 speakers working together would be an improvement. I'm also hoping that the diamond gets over the ear with a smaller inner square dimension and the air pathways are more ideal.

I do worry about the 2 edges circled in red though. I'm looking at the print and it might be a bit on the large side. For the large TyMist helmet, it's probably less of an issue.

For the speakers themselves, I'm planning on using a pre-sealed one like the ones below:

This aids manufacturing and eliminates the need to be able to print a quality cavity. Right now, since I just need any speaker (that I'd probably be able to EQ later), I'm thinking that this 64x23x18mm speaker is a good choice, at least visually:

The hope is that, for underutilized speaker directions, those speakers will be more bass focused. For example, if the virtual sound point is centered infront, then the front 2 speakers will try to reproduce the full frequency range and the rear 2 speakers will try to reproduce the bass range.

Again, I'm not that concerned about actual audio quality right now at these initial stages. Honestly, the main thing I want to do is reproduce the feeling of listening to overhead speakers in a restaurant / coffee shop / supermarket. I've actually listened to Local Forecast - Elevator WAYYYYYY more than Local Forecast, for example.

Trying the print

Oo nice the print finished just as I was about to publish and it's... actually comfortable? But... this is plastic... how could this be?

The airspace around the ear is really nice, and I think there's actually enough space for me to actually be able to make a magnetic seal attachment (copper part) for an optional seal:

The print looks really cool and modern too. I can't believe diamond-squares was the missing link to my brand aesthetic. Thanks #Tetent TestCut [gd0139].

I'm now thinking of branching this sub-project out so that I can develop without waiting for other TyMist things and then do a pull request.