[robar]

So I tested the large pk-style speakers from cklewis. So there is one properly working unit, which sounds pretty nice, impressive bass and smooth full sounding mids/treble for a 14.8mm driver. Treble is a bit rolled off. I tested in the B40 shells with stock tuning, it definitely feels like an improvement from my particular b40s. But sadly one speaker of the pair has some problem because it sounds muffled the treble is almost missing, very typical "lemon sound" maybe it got damaged on the way or I screwed it up somehow. I measured it as well, there is like 8dB minus at 8khz compared to the properly working one. This happens to me a lot and it's very frustrating because I waited for like 3+ months… I've already tried resoldering, switching shells, redoing the tuning, but it's the speaker. I start to have a little collection of the lemons :/ I'll try the sucking method if nothing helps, I have some hope because only the treble is problematic, but also getting pretty annoyed at the moment, this happened to me too many times this year, most of these were not curable, like with the titanium 64ohm when I had to ask for replacement.

 

[assassin10000]

Spent some time this evening re-tuning the 120Ω beryllium and the 150Ω redfilm.


I included the measurements I took with my 2nd version of the coupler, as they are prior to most changes and are when it was simply installed driver and center of horseshoe tuning foam on the vent (basically minimal tuning). It has a weird dip around 2.4k and measures almost flat from 2.5-8k due to weird resonance (basically 2k-8k is useless for comparisons).


Settled on the 'blue' tuning for the 120Ω Be driver for now. I may return to it to try and bring the lower mids/mid bass down another 1-2db.



If you look at the green line, this driver can be tuned almost 'flat' or monitor style neutral.

Currently have the 150Ω redfilm drivers on the 'red' setup. Haven't listened to it yet as I just epoxied the MMCX and will need to wait for it to cure.


Of all the 14.8mm drivers I've tried it has the least bass roll off.

I start to have a little collection of the lemons :/ I'll try the sucking method if nothing helps, I have some hope because only the treble is problematic, but also getting pretty annoyed at the moment, this happened to me too many times this year, most of these were not curable, like with the titanium 64ohm when I had to ask for replacement.

Man, that sucks.

Even worse is when you damage it like I did the N55 64Ω. I broke the coil wires on one making it.


Hopefully the 'suck' method worked and it was only a crinkled diaphragm from assembly.

 

[jogawag]

Of all the 14.8mm drivers I've tried it has the least bass roll off.

How about your SR2 drivers?

 

[assassin10000]

How about your SR2 drivers?

The DIY SR2 ones? I haven't measured them but I wasn't as impressed with them, so they're just sitting with all my extra drivers. Probably because I spoiled myself with the 150Ω redfilm driver that came at the same time.



Anyone in the US looking for some 14.8mm drivers to experiment with? I have a few pairs I won't be using.

16Ω SR2
https://m.aliexpress.com/item/1666829407.html

32Ω bass
https://m.aliexpress.com/item/32877041035.html

32Ω balanced mesh (one grill surround cracked on install so fits loose, can be solved with a dab of e8000 glue)
https://m.aliexpress.com/item/32230887418.html

 

[assassin10000]

Did a little more fine tuning on the 14.8mm 120Ω beryllium drivers and with my USB-C dac they are playing in the same realm as the 150Ω redfilm pk1 drivers. These definitely require a bit more power & EQ to sound their best, goes from 2nd tier DIY driver to near top tier IMO.

On the BT20S they are not quite as dynamic sounding (slightly dry or less 'wet' sounding) and treble/detail/air is slightly less.


On the blue tuning (this is with no EQ applied).

 

[assassin10000]

Forgot to post these:

The 120Ω beryllium driver covers were swapped from the 16.7mm plastic ones to the smaller O.D. stainless ones.


Measurements on 1st version coupler:


Warm, mid-centric and somewhat similar to the original Yuin PK2, except with less treble. This is without additional tuning or EQ.

Regarding the 120Ω Be drivers. They come with the larger modded PK shells and covers that are 16.7mm O.D.

I was able to safely remove the drivers and swap them into the smaller stainless steel covers 16.1-16.3mm O.D. They do have some glue holding them in and fortunately I had no mishaps.

What I did find interesting is that the MFG added an extra spacer between the driver and the inside of the cover. If you look at the picture below there is an extra brass ring that was glued in before the driver was placed. This ring is the same that is used to hold the diaphragm material around the outside edge, I placed my bad N55 64Ω driver next to the ring removed from the cover.



I wonder if it is just to prevent contact between the diaphragm and the cover or perhaps it allows for some additional soundstage and/or other sound tuning. It may take someone with better ears than me to tell. Plus I'm not going to swap the drivers back and forth to test.


Took a few minutes to take a couple quick measurements of these via my BT20S both with and without EQ & +3.0db on the bass tuner of the Wavelet app. These are the settings I came up with by ear to my preference. I switch between the red & blue graphed settings.



White = via USB-C DAC
Green = BT20S
Red = BT20S & EQ
Blue = BT20S, EQ & +3.0db bass

 

[gleanfont]

im learning from this thread! keep it up. You are so cool guys.

 

[Plicco]

This looks definitely interesting, have anyone ever heard of this rubidium driver?

€ 14,63 25%OFF | 14MM 32 ohm Flat Headphone Drivers Speakers DIY Magnetic Clear HiFi Loudspeakers Audiophile Speakers
https://a.aliexpress.com/_B0N03v

 

[assassin10000]

This looks definitely interesting, have anyone ever heard of this rubidium driver?

€ 14,63 25%OFF | 14MM 32 ohm Flat Headphone Drivers Speakers DIY Magnetic Clear HiFi Loudspeakers Audiophile Speakers
https://a.aliexpress.com/_B0N03v

I messaged a seller about those a while ago, according to them they are not good for earbud use. They are for IEM/sealed housing use.

 

[Themilkman46290]

Spent some time this evening re-tuning the 120Ω beryllium and the 150Ω redfilm.


I included the measurements I took with my 2nd version of the coupler, as they are prior to most changes and are when it was simply installed driver and center of horseshoe tuning foam on the vent (basically minimal tuning). It has a weird dip around 2.4k and measures almost flat from 2.5-8k due to weird resonance (basically 2k-8k is useless for comparisons).


Settled on the 'blue' tuning for the 120Ω Be driver for now. I may return to it to try and bring the lower mids/mid bass down another 1-2db.



If you look at the green line, this driver can be tuned almost 'flat' or monitor style neutral.

Currently have the 150Ω redfilm drivers on the 'red' setup. Haven't listened to it yet as I just epoxied the MMCX and will need to wait for it to cure.


Of all the 14.8mm drivers I've tried it has the least bass roll off.




Man, that sucks.

Even worse is when you damage it like I did the N55 64Ω. I broke the coil wires on one making it.


Hopefully the 'suck' method worked and it was only a crinkled diaphragm from assembly.

So after some tuning and playing with the 120 ohm 14.8mm, would you recommend them?
Are they worth it?
I was going to order them a month back, but had read on here that the bass is really rolled off. I have been watching your post and it seems you have had some success in tuning. I was going to try the red film, but I don't think they will compete with the 400ohm or the 130 beryllium, the 120ohm seem a bit cheaper then the red film.

 

[assassin10000]

So after some tuning and playing with the 120 ohm 14.8mm, would you recommend them?
Are they worth it?
I was going to order them a month back, but had read on here that the bass is really rolled off. I have been watching your post and it seems you have had some success in tuning. I was going to try the red film, but I don't think they will compete with the 400ohm or the 130 beryllium, the 120ohm seem a bit cheaper then the red film.

If you are looking for a higher impedance 14.8mm driver and will be driving these with a good source, I would say they could be worth it.

I think I'm the only one here that currently has them, so I'm guessing it was me that said that . And it is true without tuning (just the shell and foam on vent) the bass was terribly rolled off, about -22db from 200hz. I posted a graph showing this here:

I've not heard the 15.4mm 400Ω or 130Ω drivers. I find 15.4mm uncomfortable so I skip them. Can't help with any comparisons here.


As far as the 150Ω red film drivers, they still are my top pick for 14.8mm drivers. If you can only get a pair I would personally choose them 1st. They have better sub-bass extension and sensitivity seems a bit better matched for lower powered sources compared to the 120Ω Be.

By that I mean the 120Ω sound a bit veiled/dull/muffled on my BT20S, compared to driving them with my TC35B. The 150Ω redfilm sound fine on the BT20S, I haven't had an extended listen yet on the TC35B so they may also scale.


Edit: I've not gone back to the 40Ω Ti or 64Ω N55 drivers and re-tuned them. So they are also a potential option still.

 

[Themilkman46290]

If you are looking for a higher impedance 14.8mm driver and will be driving these with a good source, I would say they could be worth it.

I think I'm the only one here that currently has them, so I'm guessing it was me that said that . And it is true without tuning (just the shell and foam on vent) the bass was terribly rolled off, about -22db from 200hz. I posted a graph showing this here:




I've not heard the 15.4mm 400Ω or 130Ω drivers. I find 15.4mm uncomfortable so I skip them. Can't help with any comparisons here.


As far as the 150Ω red film drivers, they still are my top pick for 14.8mm drivers. If you can only get a pair I would personally choose them 1st. They have better sub-bass extension and sensitivity seems a bit better matched for lower powered sources compared to the 120Ω Be.

By that I mean the 120Ω sound a bit veiled/dull/muffled on my BT20S, compared to driving them with my TC35B. The 150Ω redfilm sound fine on the BT20S, I haven't had an extended listen yet on the TC35B so they may also scale.


Edit: I've not gone back to the 40Ω Ti or 64Ω N55 drivers and re-tuned them. So they are also a potential option still.

Thanks, I been thinking about trying some 14.8mm for my wife, she wanted to try the 120ohm, so your graphs and comparisons are very helpful.
Thanks for taking the time and effort, I beleive we all appreciate it

It's to bad you have fit issues with the 15.4mm, I was able to tune them with great success the 400ohm and 130ohm are fantastic but they also need a good powerful source to shine.

 

[golov17]

120 ohm not 14.8 mm.... maybe 15, after some tuning and glue (for original Yuin housing) sounds good..
but they demand good gain, despite 120 ohms, low sensitivity.. imho

 

[assassin10000]

120 ohm not 14.8 mm.... maybe 15, after some tuning and glue (for original Yuin housing) sounds good..
but they demand good gain, despite 120 ohms, low sensitivity.. imho

You have the 120Ω Berylliums too? Cool.

The drivers are 14.8mm. The new design shells and covers are 15.0mm. The drivers had to be glued to the covers they come with but fit perfect in 14.8mm covers.

Agreed. They need more power than many earbuds do. Typical of higher impedance and lower sensitivity drivers.

 

[golov17]

120 ohm swd2, fluff compared to them..