[Tofty]

What you initially describe sounds a little like the Snorry NM-1 headphones:

Using the head strap to tension the ear cups in sounds interesting, but the length adjustment in the a arms will vary how firm the fit is.

You've put forward some good ideas and I'll try and look at them more closely when I'm able.

 

[jason41987]

For 3D printing, I think the more joints and hinges you have in it, the more likely one of those would break. So for that, I think going with an internal suspension strap for adjustability, like AKG uses, would be better for the long term. For the clamping pressure itself, it may be possible to have something similar to that Snorry, but run an elastic band across the top, under the hinge, and to the inside of the yoke. Then you could adjust clamping force just by adding more or less pre-load to the elastic.

 

[Tofty]

Over-complexity is certainly to be avoided whenever possible. I've been struggling with how to maintain all the features I want a headband to have, while keeping things simple.

One feature I've generally tried to accommodate is to have a bridge cable between the ear cups, as I prefer not having a split input cable. For survivability this cable wants to be flexed as little as possible, but with length adjustable arms, swivelling yokes and earcups, not to mention fully folding headphone designs; the bridge cable can become the real weak point of any design. One way of mitigating this is to have an easily replaceable bridge cable, with another being to separate the routing of the cable from any headband adjustment as much as possible.
The AKG elasticated head strap design makes use of this, even using the two metal rods as the electrical connection between the two cups. Ironically from my experience the AKGs have one of the least reliable bridge cable designs I've seen, as the cables soldered to the rods at either end break easily, but at least it's an easy fix.

I personally don't like the elasticated head strap of AKGs too much. I prefer something firmer, rather than the vague floating feeling of the elastic, but something like this would certainly have it's advantages. The Monolith M1060 adjustment is more what I would go with.

This is what the headband looks like on my new "easy print" headphone design:

It's a single printed part and designed to take the Beyerdynamic DT770/990 headpad.
The band is 3mm thick and 30mm wide, which over this span gives about the right amount of clamping force.
There are also threaded holes in each side to allow nylon tipped grub/set screws to be used to adjust the tension used on the adjustable arms.

 

[Tofty]

For anybody else wanting to use the 50mm Peerless drivers in their project; they are now back in stock with Digikey:
https://www.digikey.co.uk/en/products/detail/peerless-by-tymphany/HPD-50N25PR00-32/6211129

 

[IvanDrago]

This is what the headband looks like on my new "easy print" headphone design:

Wow, these look awesome. Will you upload the files?

 

[Tofty]

Wow, these look awesome. Will you upload the files?

Thanks Ivan. Definitely, this pair was designed specifically to be a community accessible project, rather than my previous designs, which have perhaps been needlessly complicated in some aspects. I just need to get a few more parts in to confirm that everything works as intended, then I'll upload it to Thingiverse.

 

[jason41987]

For anybody else wanting to use the 50mm Peerless drivers in their project; they are now back in stock with Digikey:
https://www.digikey.co.uk/en/products/detail/peerless-by-tymphany/HPD-50N25PR00-32/6211129

What would you compare these drivers to?

 

[Tofty]

What would you compare these drivers to?

To be completely honest I haven't tried these drivers yet.
I was made aware of them on the original DIY Borealis headphone thread on reddit, but they were sold out before I had a chance to get some......until now!

They are supposedly the same drivers used in the real Aurorus Borealis headphones, as well as some of the Kennerton models and a few other well regarded models, albeit with a professional level to tuning applied.
I suppose the theory is that these drivers CAN sound really good, while some of the similarly priced drivers off ebay or aliexpress may never be able to be made to sound good, no matter how much tuning is applied. As a complete beginner in this regard I need to know I'm not going to hit a wall in sound quality and not realise it.

 

[Tofty]

Here are my fully open headphones:

I have since replaced the black rods on the headband sides for some shorter ones.

The place holder drivers I've used sound absolutely terrible and the ear pad foam isn't comfortable at all.
I don't really know what to do about the pads, as large outer diameter, yet narrow and thin pads don't really exist (possibly the Beyerdynamic DT770/990 pads might work), but at least I can now swap out the drivers for some of the Peerless ones and test if this design has any value whatsoever.

The CAD files can be found on Thingiverse: https://www.thingiverse.com/thing:5164152

 

[Tofty]

Tofty Headphones 6: Easy Print

These aren't completely finished yet, as the drivers are missing, but externally everything's done.
In terms of headband comfort and function; I'm pretty happy with how they turned out.

The headpad is the Beyerdynamic DT770/990 type, although this one is just a cheap copy.

All connectors are 3.5mm TRS jacks.

Earpads are 105mm in diameter.

Files for this design can be found here: https://www.thingiverse.com/thing:5169031

 

[Tofty]

Just a bit of an update...

I installed the drivers and finished the wiring on my TH6 easy print headphones.
The drivers aren't the ones I initially planned on using. I bought some $4 ones off ebay, since this is supposed to be a very accessible build, but when they finally arrived; the diaphragms were creased on both and on one it wasn't glued down all the way round either, so I binned them off and used some I'd removed from a very cheap gaming headset (the same headsets I got the metal headband from for my first two headphone designs).

I also made a second set of the same ear cups, but this time with the Peerless drivers and open-back grills.

These are to go with a different headband design I'm still waiting on parts for (mostly waiting on shorter black standoffs and some elastic material).

I had a go at redesigning the geometry of the Borealis headphones, as it was a bit off how the earcups felt like they wanted to twist off the head a little too easily.
This is what I came up with and it feels like a real improvement.

It also now has proper swivel limits, which were lacking previously.

I was asked to make a more printable version of the Borealis, so I repurposed the headband from the easy print TH6 model, with new forks into this hybrid.

My current project is a completely standalone wireless set of headphones, that aren't bluetooth, but rather have an mp3 player built in with a microSD reader and a huge battery. These are specifically for listening to audio-books with, as I personally prefer having dedicated devices, rather than having everything done via a smart phone. I have all the parts I need, including a DFPlayer Mini, which will act as the DAC. The battery will be an 18650, so it should last for weeks.


One last project was to create a headphone wall, as I've accumulated quite a few sets I've repaired over the last year.
The hangers are 3D printed of course.

 

[re23071998]

any cons of such open design?
also how would you tune them?

 

[Tofty]

any cons of such open design?
also how would you tune them?

Sorry which open design specifically?

Do you mean the black and gold one?
If so the main negatives would be the loss of bass.,
They were inspired primarily by the Sony MDR-F1 headphones, which are similarly open. I just wanted to hear what that arrangement might be like after I read a post by someone lamenting that such open headphones were no longer available.

I suppose the main forms of tuning would be filter paper and/or fabric in front of the driver and at the rear; changing the venting in the centre and round the rim.

 

[re23071998]

Sorry which open design specifically?

Do you mean the black and gold one?
If so the main negatives would be the loss of bass.,
They were inspired primarily by the Sony MDR-F1 headphones, which are similarly open. I just wanted to hear what that arrangement might be like after I read a post by someone lamenting that such open headphones were no longer available.

I suppose the main forms of tuning would be filter paper and/or fabric in front of the driver and at the rear; changing the venting in the centre and round the rim.

got it,
yea the black gold

 

[Tofty]

I've completed the new Borealis build and have updated the Thingiverse page with loads of new files, photos and build info: https://www.thingiverse.com/thing:5103331

I finished the rigid headband build. Unfortunately this design doesn't work very well, as it's not really possible to deliver enough clamping force with this arrangement. They are just about usable, but the design needs a rethink.

I haven't made much progress with the design of the Audio-book headphones, although I did do a mock-up build of the electronics, with the planned power switch and button arrangements and it all works as it should. One issue though is that when the DFplayer Mini is powered off it looses it's place on the mp3 that I was playing, so the circuit needs to be left powered between listening sessions of each audio-book. This shouldn't be a problem with the huge 3.4Ah battery I plan to use, but that needs to be tested in the actual use scenario.

The things missing are of course the second speaker, along with the 18650 Li-ion battery and a USB-C battery charger board. This should allow the headphones to be charged while still powered on, if that's ever needed.


I've posted this elsewhere a while ago, but it's relevant for here:
For my next big project I want to have a go at making a headphone tuning testbed.
I want to make a frame that allows for quick, tool-less swapping out of various parts, to help identify what specific changes do to the headphone's sound profile and the listening experience.

My plan would be to get hold of some MiniDSP EARS (bought them over the holidays) for the more objective measurements and make 2 or 3 pairs of these headphones for side by side direct personal sound comparisons. I'm basically aiming for the audio version of those glasses they use an the opticians; with the clip in lenses.
This is meant as a design that hopefully others will find of use for their own tuning experiments, so I want to try and include as many features as possible and incorporate people's suggestions, as I really don't know what I'm doing.

Firstly, does something like this already exist? What kind of setups have others used in the past?

What things can be adjusted to change the sound profile? (ignoring different drivers and the altering of their venting for the moment)
Open Vs Closed back would be the most obvious variable,
Different side wall and general cavity shape,
Resonators and focusers behind the driver,
Venting around the driver and the specific materials used for any baffling,
The poke guards in front of the driver and any baffling material that may be used here,
Ear pads, thickness, shape, material, etc
Headband clamping force,
Anything else I'm missing?

For the headband design I'll probably use something similar to the rigid headband design shown above, just with the elastic adjuster replaced or at least supplemented with a screw adjuster, so the clamping force can be altered manually (this will likely end up being significantly changed to how they are now). The swivel design, which allows the ear cups to turn 90 degrees and lay flat on a surface will be helpful for the replacing of parts.
The arm length adjustment will probably have some form of locking system applied; to keep everything in the same place when the headphones are constantly being put on and taken off.
Forks will become a bit wider; to allow for a larger outer ear cup frame, with room for all the variable components to fit inside of it. The attachment points between the forks and ear cup will either be thumb screws or something super quick release like a Dzus Fastener.
The diver will be retained in a little padded cradle and attached to the outer ear cup frame with minimal spurs. Everything else in front of and behind the driver will slot into the outer frame.

That's as far as I've got so far.