[ALMS]

I didn't know the Superlux drivers would just pop out of the baffle like that. Good to know!!

Getting a new amp won't change the tuning of the headphone

It might be that the diaphragm is actually touching the baffle - this might be preventing excursion and muting bass frequencies. If this possibility has been eliminated from troubleshooting, I'm not sure what else you can do other than go open-back. Those ear pads should be delivering bass.

Yeah, it did require a bit of 'persuasion' to pop out the drivers, if you know what i mean

Hm, alright. I'll do some tests with the drivers free-floating and see if the issue persist otherwise it must be a tuning challenge.

 

[frank2908]

I had some experience with dynamic drivers. Looking at the gold driver, they are completely open on the back side, and given that the volume of the dt770 cup is quite large, you can get good bass out of these. Looks like the diaphragm touching issue, and you may need to replace the white paper cover the front driver with some thing else less obstructing sound. ( More open mesh fabric). Also try to seal the baffle and driver assembly. Looks like the connector mod may have produce some leak from the back cup to the ear side. This will reduce bass and mid drastically and make treble very peaky. You can try sealing them with doubke sided foam tape on this opening, and apply more foam tape to cover the rest of the white paper on the baffle. Also use blue tack to seal around the driver.
After doing this the sound maybe too bassy and thick mid, you can try to add some damping with cotton ball or wool or synthetic damping materials to damp them

 

[interface95]

Obviously tuning headphones is more difficult than tuning loudspeaker, because you have to take into consideration many more aspects like the transfer function of our ears. Or even the resonance of the air volume between the ear and the driver.
Said that, all of these effects are even more present in closed headphones.
And because of that, I strongly recommend to begin with open headphones.

You just can't mess up the whole impulse response, and try to fix the sound with an EQ a little bit.

 

[almuzzi]

Just tried out the K88s...very good imaging and detail with a lot of damping. Removed the tape covering the hole in the middle, which brought up the bass and "impact".

 

[Slater]

Just tried out the K88s...very good imaging and detail with a lot of damping. Removed the tape covering the hole in the middle, which brought up the bass and "impact".

When you say a lot of damping, do you mean a lot of damping is required to make them sound good?

 

[almuzzi]

Yep, a layer of felt and then filling up the cup with cotton balls. Once damped though they sound shockingly good!

I am thinking of trying out passive radiators on the back of the cup. Will update.

 

[GREQ]

Just tried out the K88s...very good imaging and detail with a lot of damping. Removed the tape covering the hole in the middle, which brought up the bass and "impact".

Have you tried more porous baffle venting like Beyerdynamics?

 

[almuzzi]

Nope. This is the first time I'm building headphones so I'm still looking out for features to add. For now, everything (the cup, pad holder, body) is twist on/off for ease of tuning so I think baffle venting can be easily added - just need to alter the design (as below) and print the body.

What would you recommend I use to cover the vents? Transpore/masking tape?

 

[GREQ]

Surgical tape would be OK for testing, I wouldn't consider it a permanent solution due to the eventual 'sweating' of the adhesive, which will decompose or denature after 1 or 2 years.
I'm not sure what the best permanent replacement would be, but I would look for thin/porous 'exotic' paper materials for a start.
They're cheap and hold their shape when cut.

Some fabrics might be another reasonably cheap alternative, but they're difficult to keep in a flat/tight form.
If you're feeling extra fancy, a ultra-thin wire-mesh filter could also be used, like on HD650. But that would be the most expensive, and you might not like how it sounds.

 

[almuzzi]

Thanks for the tips!

As they are now the headphones have just south of enough bass so I'm not sure if a vented baffle would help (you will note that the baffle holes I included for tuning were taped up). That might change with passive radiators though so I'll definitely print out a pair (once I get my MPSM nozzle unclogged) to test.

Any other 40/50mm drivers to recommend? I found a few on Aliexpress - beryllium and the othe K-series drivers - but they're quite pricey

 

[KThife]

Thanks for the tips!

As they are now the headphones have just south of enough bass so I'm not sure if a vented baffle would help (you will note that the baffle holes I included for tuning were taped up). That might change with passive radiators though so I'll definitely print out a pair (once I get my MPSM nozzle unclogged) to test.

Any other 40/50mm drivers to recommend? I found a few on Aliexpress - beryllium and the othe K-series drivers - but they're quite pricey

Maybe u can try these?

Those are quite interesting. They are 40mm bio-cell 22ohm with sensitivity of 95db. It's also a Chinese knock off of bowers and wilkins P7 drivers.

Would love to know how those would sound like because a buyer that replaced his dead p7 driver with these apparently says it sounded as good as his original p7 drivers.

Links for the drivers :
https://m.pt.aliexpress.com/item/4000064562471.html?spm=a2g0n.seo-amp-detail.reviewList.0
The link i shared is a bit pricey. Try too search around to see if any vendors is selling it in a cheaper price

Ps: Also it's my first post here, I've been following this thread for years but i can't figure out how to post my own photos that I've shot with my phone. Hope that i can get some help here and can finally able to post some driver pics in my favourite thread!

 

[528068]

Has anyone compared K99 to the 540ohm bery driver? Also for the comparison I mainly prefer the 500ohm version of k99 to make the comparison more fair

 

[528068]

@almuzzi Have you tried out the K99 500ohm model before? I'm very interested in buying the 500ohm k99 for my 3d printed headphone which is a re-design of that Armadillo headphone because I cannot be bothered to learn about modelling in 3d software. And about that headphone you produced through 3d printing, is it necessary to have a grill pattern that is right in front of the membrane for the grill part?

 

[almuzzi]

@TheBigCheese I haven't tried those yet - thinking of getting either those, the beryllium ones, or the P7 replacements (which @KThife very kindly pointed out).

I'm leaning towards the beryllium ones due to the pretty good reviews in this thread - someone did a comparison a couple of pages back.

On the design, 3d modelling isn't that hard. I picked it up over a couple of hours, and I have zero engineering or design background. Managed to work out my current design over a week or two - working on it after work. I'll put my STL files up on Thingiverse at some point and post em here.

 

[KThife]

Talking bout the K100 drivers, they recently came out with a 64 ohm ver in Tao bao. So now there's 3 versions of the drivers, 32ohm, 64ohm and 500ohm.

Other than that, here are some photos and some description on how they sound by some buyers. U guys might be interested~

"Silent reversion" of the K100 drivers?
Here are the pic seller shows

And here's from a buyer

According to the pic above from a buyer, there might be a "silent reversion" for the drivers. As u can see the "composite layer" of the drivers is alot more thin and brittle than the pic they show in Ali / Tao bao. The buyer also commented that the driver arrive like that with some damage on the diaphragm and the composite layer looks cheap compared to the sellers pic. He bought his unit in early 2020 dis year, So be aware??

Now for some description and comments on how they sound by some other buyers~

^ K100 500ohm ver : "On a quick listen, they have great soundstage and can reproduce highs and mids in a recording very precisely. Resolution vise these are not bad."

^ K100 500ohm ver (Note u can see it measure way below 500ohm) : "Ive play with alot of high impedance headphone, these are actually not that hard to drive. Heaven't play with their filter papers yet, in this headphone casing they have a large soundstage with almost like a dark background surrounding it. Their low end is abit meh but overall it's a high quality driver."

^ K100 32ohm ver : "High quality drivers, their resolution is almost on par with some planar. They are loose and full in the low end, precise imaging with wide sound stage. If their high frequency extension is abit better then it will be perfect."

Note: Im only sharing and translating other peoples opinions. They all uses the same drivers but with different mods, shell and most importantly audition by different people. So pls take all the words above with grain of salt~ Sorry for the long post, hope it's helpful!!