[furyossa]

Yes I've seen the diy bud with your dream shells and the 400ohm To be honest, the finish doesn't look so good, the edges are quite rough on around the back vent for example. By the way, how do you tune a shell like that reliably? What sort of material do you put on the vent? I never had an open back shell before, so my main concern is how do you get reliable channel balance, how do you put something on those vents that covers the whole thing tightly and wouldnt get loose after a few days or weeks.
(we're talking about this shell https://www.aliexpress.com/item/1005001773416768.html and this earbud https://www.aliexpress.com/item/1005001836926242.html )

I have open back buds, but they not have such a big vent hole. In the case like this I will probably combine a couple of things
First I will add another "dust" steel mesh from inside to block air a bit more https://www.aliexpress.com/item/32800734441.html
Instead of steel mesh you can use small pieces from something like this (only hook) part without adhesive https://www.aliexpress.com/item/4001052968496.html
Another layer will be cotton filter (round part) https://www.aliexpress.com/item/2046606985.html , or this inner part https://www.aliexpress.com/item/4000250823937.html
More of this but for headphones https://www.aliexpress.com/item/2035370421.html
At the end if this is not enough you can always stuff the cavity with some absorbent material (sponge, mop ...)

 

[robar]

Thanks @furyossa very interesting
One of my possible projects for this year is to mod and upgrade my old semi-open AKG K514 which uses 40mm drivers. I already changed the front filters and earpads and the sound improved a lot, it's actually enjoyable now But I want to take it further, redo the tuning on the back vent (I guess same principles apply here as open back earbud), upgrade the cabling and even the drivers and headband. If you know some good quality 40mm drivers from aliexpress or good diy cables for one-sided headphone cabling (or maybe I convert it to Y cabling or just female connectors) I'd be happy to hear! We can continue via pm if other's don't wanna chime in, I guess this is getting pretty offtopic I also have a vintage silver AKG K141 which also needs some tuning work inside, recabling and earpad mod etc
I just need to figure out how to measure headphone freq response with my field recorder Maybe I'll make a little "flat bed" rig or just a wooden square with a hole inside

 

[furyossa]

Thanks @furyossa very interesting
One of my possible projects for this year is to mod and upgrade my old semi-open AKG K514 which uses 40mm drivers. I already changed the front filters and earpads and the sound improved a lot, it's actually enjoyable now But I want to take it further, redo the tuning on the back vent (I guess same principles apply here as open back earbud), upgrade the cabling and even the drivers and headband. If you know some good quality 40mm drivers from aliexpress or good diy cables for one-sided headphone cabling (or maybe I convert it to Y cabling or just female connectors) I'd be happy to hear! We can continue via pm if other's don't wanna chime in, I guess this is getting pretty offtopic I also have a vintage silver AKG K141 which also needs some tuning work inside, recabling and earpad mod etc
I just need to figure out how to measure headphone freq response with my field recorder Maybe I'll make a little "flat bed" rig or just a wooden square with a hole inside

I think that any mod related to dynamic drivers of any size would be a very interesting topic because many principles can be applied to earphones. When I mention "any size" I also mean also the loudspeakers. That area has so many innovative things about tuning and many things can be learned from there.
Also, most of us know each other well on this thread, so I don't believe anyone will mind, and to be honest many DIY threads are not as popular and "alive" as this one
Classic earbuds in comparation with headphones and IEM are much easier and cheaper to do mod and tuning.
I’m still collecting ideas and tuning material for my Sony and Sennheiser headphones. The stock cable and pads are around 30euros each which is expensive. Both models have two-way cable, HD25 Light has 2Pin sockets, but I can't find in my country
only the connectors to make balanced braided cable. Sony MDR-570 LB use non-removable cable, maybe I'll put standard MMCX. I will replace this "weird" pads with classic one. It's interesting that this model use 30mm driver but plastic frame around driver measure 80mm diameter. I need pads that can wrap around 80mm. HD25 Light use 70mm pads.

There are a couple of threads, but they are not active for quite some time
https://www.head-fi.org/threads/just-listened-to-some-fostex-t50rps-today-wow.452404/
Mass Loading and Damping


Cable replacement

 

[headenvelopedinsound]

I use my 400 and 600oms with DIY metal shells and yes, the bass is more tight, deep, punchy but because shell has open back vent I can control whether they are more intimate or spacious.
And of course the size of the cavity also has an effect here.

Yeah I pulled the drivers out of shells really similar to your DIY, think you stated your previous favorites. I found I couldn't really tune them to my liking in those but I also admittedly didn't try that hard. I wanted a change overall and am really pleased with them now. I put the 400ohms in some large metal open back shells and they sound really good but still the same issues I had in the other metal shells. I've got some felt that I lined my MSUR N650s with and going to experiment with that. Overall I really like the 600ohm in the M2 Pro shells with the stock tuning module. Got me thinking what an ST10s shell would sound like. I'll post some pics tomorrow to show what I am referring to.

 

[furyossa]

I just need to figure out how to measure headphone freq response with my field recorder Maybe I'll make a little "flat bed" rig or just a wooden square with a hole inside

https://www.aliexpress.com/item/32330952194.html
https://www.aliexpress.com/item/4001094165717.html
https://www.aliexpress.com/item/1950602389.html
https://www.aliexpress.com/item/1144636237.html
You're welcome

 

[furyossa]

Got me thinking what an ST10s shell would sound like

I hope better if you not have a problem with the fit issue. It's a bit larger shell?
Probably because of the size you will have spacious sound and TL is longer which will affect low-end even more

 

[headenvelopedinsound]

I hope better if you not have a problem with the fit issue. It's a bit larger shell?
Probably because of the size you will have spacious sound and TL is longer which will affect low-end even more

I’ll be experimenting with tuning and your post is excellent above to start on. I am use to tuning headphones but earbuds are on such a small scale comparatively it’s just not been something I’ve messed with extensively.

I’ve got the original st10 and it is great. No fit issues. I wear them down instead of over ear(just swap left and right). But yeah that’s what I am thinking. A little more bass depth and larger stage. I don’t want to take apart that set as I really am happy with them. But I am sure with my heat gun and time I can get the st10s drivers off.

As far as measurement I just use this https://www.daytonaudio.com/product/1117/imm-6-idevice-calibrated-measurement-microphone

I have measured out a tube to have a 1inch space between the earbud and mic. Works well for me except I can’t really do anything above 10khz reliably. It’s good for personal reference.

 

[furyossa]

I’ll be experimenting with tuning and your post is excellent above to start on. I am use to tuning headphones but earbuds are on such a small scale comparatively it’s just not been something I’ve messed with extensively.

I’ve got the original st10 and it is great. No fit issues. I wear them down instead of over ear(just swap left and right). But yeah that’s what I am thinking. A little more bass depth and larger stage. I don’t want to take apart that set as I really am happy with them. But I am sure with my heat gun and time I can get the st10s drivers off.

As far as measurement I just use this https://www.daytonaudio.com/product/1117/imm-6-idevice-calibrated-measurement-microphone

I have measured out a tube to have a 1inch space between the earbud and mic. Works well for me except I can’t really do anything above 10khz reliably. It’s good for personal reference.

For headphone measurement is logical that we need the silicon ear for DIY measurement rig. Ear shell in real life absorbs and reflects the sound.
iMM-6 will perfectly fit inside ear hole on the other side. I’ve been playing with coupler design for the last couple of weeks. At first I thought I had a problem with the DIY measurement rig but in the end with the expert advice of @assassin10000 I managed to find out that the problem was coupler size and shape. Also see the latest video from @jude about new measurement system.

You are the crazier than me in a good way of course.
At least I disassemble a little more expensive earbuds that don't sound good, so I don't mind in the end if something bad happens. You're planning to break up a pair that's already works and sound well. That's the charm of this hobby! I totally support you in that
You can probably find on the internet that someone is selling a broken ST-10. Maybe that would be a smarter solution

 

[robar]

https://www.aliexpress.com/item/32330952194.html
https://www.aliexpress.com/item/4001094165717.html
https://www.aliexpress.com/item/1950602389.html
https://www.aliexpress.com/item/1144636237.html
You're welcome

Thanks, but I don't plan to buy any ears soon I only want to measure the relative difference between different mods to the same headphone. The purest signal I can get from it, the more reliable the measurement gets. The graphs won't be similar to a standard measurement with a dedicated head, but I don't need it. My goal is to check channel balance and see the effect of different filters/vents/drivers on the same set of headphones. Maybe compare headphones that are very similar in terms of earpad design. But I wouldn't compare lets say an on-ear vs circumaural. Anyways, even if I buy a hard plastic ear, that will be also very different from a real ear, it would just make a lot of random resonance in my opinion that would make my life harder. For my purpose, the simpler the better I think.

 

[headenvelopedinsound]

For headphone measurement is logical that we need the silicon ear for DIY measurement rig. Ear shell in real life absorbs and reflects the sound.
iMM-6 will perfectly fit inside ear hole on the other side. I’ve been playing with coupler design for the last couple of weeks. At first I thought I had a problem with the DIY measurement rig but in the end with the expert advice of @assassin10000 I managed to find out that the problem was coupler size and shape. Also see the latest video from @jude about new measurement system.

You are the crazier than me in a good way of course.
At least I disassemble a little more expensive earbuds that don't sound good, so I don't mind in the end if something bad happens. You're planning to break up a pair that's already works and sound well. That's the charm of this hobby! I totally support you in that
You can probably find on the internet that someone is selling a broken ST-10. Maybe that would be a smarter solution

I actually got my st10 from assassin haha. It’s staying as is and yeah I am experimental when it gets right down to it. So this probably is the most pics I've posted on this site but here we go. An updated display of my DIY(excluding the stock silver M2Pro driver I stuck in a shell) AND my measuring rig with some samples.

From left to right we have 600 ohm, 400ohm, 64ohm Ti, and then I think it is a 32ohm N50 Red Film.

Then we have the inside of the M2 Pro shell with 600ohm Driver and stock tuning module

Now my measuring rig with some samples and using the ST10 as a baseline for general accuracy of my rig.

So you can see it has an opening that funnels to accommodate full coverage of driver, I always use donuts to get good seal and exposed driver head.

Here is the baseline, if I need to remove the pulled image from hiendportable.com let me know.

And this is my St10 measurement

and now just to see what I have for the 600ohm

Would love to see the peak move from the 2.2khz to 2.8khz but believe this is just the nature of the driver itself and that kind of shift probably isn't possible. If you tuning gurus know how to get that shift please enlighten me! Either way this is probably my favorite set right now, need to live with it longer in this state but overall I am very pleased

EDIT: I knew I forgot something... here is the ST10 and M2 Pro. From the look of it the shell cavity is actually bigger on the M2 Pro with the TL being obviously bigger on ST10 so it stands to reason that bass would be the biggest difference here. Probably going to cool my jets and enjoy things as is for now.

 

[furyossa]

These are my measurements for 600ohm Beryllium, 400ohm Graphene, 130ohm Beryllium and 64ohm Titanium
BTW... I use the same shell as yours for 64ohm Ti for my 130ohm and 64ohm models

Now you can see why 400ohm graphene has balanced sound signature

 

[headenvelopedinsound]

These are my measurements for 600ohm Beryllium, 400ohm Graphene, 130ohm Beryllium and 64ohm Titanium
BTW... I use the same shell as yours for 64ohm Ti for my 160ohm and 64ohm models

That's pretty much what my readings show as well when I lightly break the seal by moving the earbud at a small angle or just balance it freestanding on top of the opening. Except I don't have the 130ohm.I tend not to do it as it is easier for me to read the fully pressed readings anymore. All it takes is to just ever so lightly shift pressure so the seal on one side is eased up. In essence it is more likely the bud sits flush and firmly in the bottom of our ear and lightly lifts away at the top of the ear. Giving the more traditional readings like you have above. I wish I liked my driver 400ohm more but it's just something about the texture I don't enjoy as much as the 600ohm. It has the proper 3khz peak but more bloated bass. I definitely feel the lower mids are much better with the new shells on the 600ohm now as apposed to the previous, which it was in the same type as my 64ohm Ti.

I was just looking at the 130ohm driver yesterday but they are $33 right now which is the same as the 600ohm... You know a better place to get that driver for the old cheaper price?

 

[furyossa]

Wow, they double the price on 130ohm Bery. This is not good, and it seems a little rude to me, but I will not interfere in their politics.
That's why I bought 3 pairs, and I was supposed to do the same for 150ohm red film, 400 and 600ohm but now is too late.
This is how the current situation looks like when you want to order from my country. They're killing me with this abnormal shipping and this has been going on for almost a year now.

I use EVA foam for my coupler to reduce resonance from a plastic tube. EVA foam is like human skin, it's soft and act like absorber.
I noticed that by reducing the internal volume, it has a lot of effect on the final measurement. Also, we need to use "lightly" seal, as close as possible to the natural way of wearing earbuds.
The average length of the ear canal is around 25mm and the diameter is around 7mm. Now what is also important?
The section of the ear canal has an elliptical shape and not circular like an ordinary tube. The second and perhaps most important thing is that the ear canal is curved in length and changes its diameter.
This is my analysis and re-design tor iMM6 DIY coupler

This is the current version #3.
#4 will be curved model

 

[headenvelopedinsound]

Yikes those ship prices are insane. They are just saying don’t buy it basically... that’s got to be frustrating. I did do some fancy curved tube design with a bike handle grip but just didn’t work out as well as I had hoped. Honestly I am more than happy with my little rig as is. It’s made from a kids medicine syringe tube. For me it gives me good idea for what my drivers are doing but again why I don’t post them publicly, just personal reference. If I was going to go all out I would get the standardized coupler and ear simulation. Like this
US $55.20 8％ Off | Headphone Curve Tester Artificial Ear Artificial Ear IEC711 Frequency Response Curve Waterfall Chart Base Version
https://a.aliexpress.com/_m01uPTf

but at like $250 all in I am good. Even $40 I’d rather get another M2 Pro and just live with My little $15 measuring rig.

I am very use to 2.1 studio monitors and as such I think the M2 Pro shells are a good fit. I asked Smabat if they were going to offer just the shells again but not heard anything yet. The M2 Pro is $45 right now and seems like a good bet to go ahead and get another set so I can experiment some more. They are just so comfy. M1 Pro sounds great but due to it being a smaller driver just doesn’t have the same impact and spatial sensations as a larger driver.

I know one of my 400ohm drivers has a nasty notched dip around 1khz. It’s just one of them. So maybe I should just buy another set and see if it’s just my drivers I don’t like.

 

[headenvelopedinsound]

Yikes those ship prices are insane. They are just saying don’t buy it basically... that’s got to be frustrating. I did do some fancy curved tube design with a bike handle grip but just didn’t work out as well as I had hoped. Honestly I am more than happy with my little rig as is. It’s made from a kids medicine syringe tube. For me it gives me good idea for what my drivers are doing but again why I don’t post them publicly, just personal reference. If I was going to go all out I would get the standardized coupler and ear simulation. Like this
US $55.20 8％ Off | Headphone Curve Tester Artificial Ear Artificial Ear IEC711 Frequency Response Curve Waterfall Chart Base Version
https://a.aliexpress.com/_m01uPTf

but at like $250 all in I am good. Even $40 I’d rather get another M2 Pro and just live with My little $15 measuring rig.

I am very use to 2.1 studio monitors and as such I think the M2 Pro shells are a good fit. I asked Smabat if they were going to offer just the shells again but not heard anything yet. The M2 Pro is $45 right now and seems like a good bet to go ahead and get another set so I can experiment some more. They are just so comfy. M1 Pro sounds great but due to it being a smaller driver just doesn’t have the same impact and spatial sensations as a larger driver.

I know one of my 400ohm drivers has a nasty notched dip around 1khz. It’s just one of them. So maybe I should just buy another set and see if it’s just my drivers I don’t like.

Ok so I noticed there isn’t any info on the 500ohm beryllium so I bit the bullet and got it. Am going to just hope Smabat starts selling the M2 shells again at some point.

US $29.64 20％ Off | GHXAMP MX500-S500 Earphone Speaker Unit 500 Ohm Beryllium Membrane Full Range Earpiece Driver 102.33dB Repair Earphone Parts 2pc
https://a.aliexpress.com/_mMig8Yd