DIY Earbuds
Nov 3, 2019 at 5:39 AM Post #1,158 of 4,721
it's driver cover looks like 14.8mm rather than 15.4mm.. also some has orange point while some has purple, if it makes any sense..
Maybe they did a special PK plastic covers-like to be adapted to 15.4mm ? not sure what to trust so yeah for now it's safe to think it's 14.8.
 
Nov 3, 2019 at 6:58 AM Post #1,159 of 4,721
I have indeed used these drivers on standard MX500 shells, very good vocal performance

20191103_115252[1].jpg
 
Nov 3, 2019 at 8:31 AM Post #1,160 of 4,721
These speakers look very similar to what B40 uses. The front cover and the inner layout looks very similar, the only real difference visually for me is that B40 has thin white foam on the vents.
https://www.aliexpress.com/item/4000294994624.html
Fun fact: the B40 front cover is not complatible with anything I have (too deep for my 14.8mm shells but the diameter is too small for 15mm ones), except for the shell of Panasonic RP-HV095E. That Panasonic shell is of good quality and very comfortable but the sound is bad due to almost no vents, I'll try to mod it and see what happens :)

edit: there are small differences, I see 2 notches on the listing while B40 has one, and the cover holes look a bit smaller on the B40. Maybe the cover surface is more curved with the B40 but it's hard to tell. So probably not the exact same unit, but definitely related in some ways, maybe NiceHCK customized these drivers for the B40. All of it is just a theory of course
 
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Nov 3, 2019 at 9:52 AM Post #1,161 of 4,721
P1310182_DxO.jpg P1310185_DxO.jpg
B40 driver. I quickly swapped the drivers with another B40 as an experiment because there was a significant channel imbalance, so the soldering quality is my crime :D (the solder was quite hard to heat up for some reason and I was very frustrated with the whole thing when I tried this haha) The swapping improved the situation by the way, the two channels were different in both of my copies so in this instance I replaced the right speaker with the other pair's left speaker.

edit: Now the curves are the same with the two lefties, just one side is 2dB louder than the other, not sure why. Compared to Qian69, the sound is somewhat similar but softer and smoother with less bass impact and thinner vocals. I'm not sure if this is the same as the intended sound but this was the only usable configuration with my units
 
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Nov 4, 2019 at 4:31 AM Post #1,162 of 4,721
(the solder was quite hard to heat up for some reason and I was very frustrated with the whole thing when I tried this haha)
Sometimes you need to add some tin (almost a very little ball) at the end of the solder tip to help unsoldering wires from drivers, at 300°C it should do the trick :)
 
Nov 4, 2019 at 7:28 PM Post #1,164 of 4,721
Drivers do have to be matched. Even expensive brands take great care about it.
yes of course, but what was very strange and disappointing to me that the B40 channels had very significant differences, and very similar across multiple units, as if the left and right drivers were from completely different batches or something. My other cheap earbuds have much better matching, the best of all is my Qian69 which has virtually the exact same response in both channels according to my measurements.
First graph is my new B40 set in original imbalance, second is the two left drivers in new set, third is the two right drivers in old set. As you can see very big difference below 400hz. Again 250hz/1.2khz bump are resonances in my setup, I still haven't figured it out how to compensate it in REW haha
B40_new_channel-imbalance.jpg
b40_new_fix_v1_l-vs-r.jpg
B40_old_fix.jpg
Sometimes you need to add some tin (almost a very little ball) at the end of the solder tip to help unsoldering wires from drivers, at 300°C it should do the trick :)
Yep, thanks for the tip :) It had some coating or different material I think because the smell was very different too.
 
Nov 5, 2019 at 9:35 AM Post #1,165 of 4,721
Can anyone say how are the 130ohm beryllium vs 600ohm beryllium?
 
Nov 6, 2019 at 3:26 AM Post #1,166 of 4,721
Can anyone say how are the 130ohm beryllium vs 600ohm beryllium?
I don't own 600 but from what I think/readed the 600 looks to have slightly more bass (& more sub-bass especially?), but overall presentation/sound should be the same. All depends of course of the driving power to match the same.
600 ohm is very difficult to power in quality. That's why I generally prefer to stuck max at 150/300 ohm.
 
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Nov 6, 2019 at 3:53 AM Post #1,167 of 4,721
I don't own 600 but from what I think/readed the 600 looks to have slightly more bass (& more sub-bass especially?), but overall presentation/sound should be the same. All depends of course of the driving power to match the same.
600 ohm is very difficult to power in quality. That's why I generally prefer to stuck max at 150/300 ohm.
Thanks. Ordered them couple days back, couldn't find any info except one post on here that said they are totl level, guess I will have to order the 600ohm later, coming for samsara, going to miss the sub bass...

Thanks for the response
 
Nov 8, 2019 at 9:30 PM Post #1,168 of 4,721
Has anyone modded Qian69? I'm mainly interested in the recabling process, is the backplate removeable? I pulled out the cable but a metal clamp is dangling inside the stem which I can't take out. Btw I dont recommend opening up Qian69, the driver were torn apart immediately... :/
 
Nov 12, 2019 at 7:27 AM Post #1,169 of 4,721
After many modding tries and finally back to stock shells, I can confirm that my other set of 150 ohm red fim drivers that I ordered in september last is defective, one of the unit (left of right) is definitely not sounding the same as the other one.
I tried contacting Chitty's store (aliex) but they explained to me the cost it too high to send only 1 unit... and that they will wait for my next order to place a free unit as replacement, which is nice but I had no plan to buy something from this store for now.. lol
A bit sad then to not finalize another "GXaudio PK150" :frowning2: :D

In the meantime for that 11.11, I decided to get another 130 ohm beryllium but with metal covers instead of generic black plastic (hopefully a bit better sub-bass presence with these kind of covers), and a pair of 500 ohm beryllium drivers, I'm curious :)

*edit* : finally chitty store arranged me, offering 10$ for a new pair of PK1 red film drivers, I accepted that offer. Good service from the store I would say.
 
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