[Ahmad313]

Dont see any electrical crossover components like resistors or caps. Also no sign of dampers. DD doesnt look like Sennheiser either.

 

Please if it is possible can you check the Rose b&r5 drivers iem they have the crossover are not and what is your idea about sound quality , actually i am intersted in that iem and waiting for some impressions .

 

[MuZo2]

Dont see any electrical crossover components like resistors or caps. Also no sign of dampers. DD doesnt look like Sennheiser either.

 

Please if it is possible can you check the Rose b&r5 drivers iem they have the crossover are not and what is your idea about sound quality , actually i am intersted in that iem and waiting for some impressions .

I might be wrong about above iems, just saying what I am seeing in pics.

 

[ForceMajeure]

Actually you can see the dumpers in the above pic also you can see the sound tube coming out the DD.
 
By the way the DD used is the 7mm "ie800" very common DD with elevated bass and suposedley wide stage

 
https://world.taobao.com/item/521492293686.htm?spm=a312a.7700714.0.0.nMVBuy#detail
https://world.taobao.com/item/44016951575.htm?spm=a312a.7700714.0.0.nMVBuy#detail

 

[hellfire8888]

  Actually you can see the dumpers in the above pic also you can see the sound tube coming out the DD.
 
By the way the DD used is the 7mm "ie800" very common DD with elevated bass and suposedley wide stage

 
https://world.taobao.com/item/521492293686.htm?spm=a312a.7700714.0.0.nMVBuy#detail
https://world.taobao.com/item/44016951575.htm?spm=a312a.7700714.0.0.nMVBuy#detail

the link provided is invalid..but i do manage to search 7mm ie800 driver in taobao and get the same result..
just notice Knowles TWFK-30017 is roughly 150 yuen it is very expensive to diy!!

 

[MuZo2]

  the link provided is invalid..but i do manage to search 7mm ie800 driver in taobao and get the same result..
just notice Knowles TWFK-30017 is roughly 150 yuen it is very expensive to diy!!

There are Chinese equivalent of TWFK which are 10 times less expensive. Less than 10$ for pair.

 

[MuZo2]

  Actually you can see the dumpers in the above pic also you can see the sound tube coming out the DD.
 
By the way the DD used is the 7mm "ie800" very common DD with elevated bass and suposedley wide stage

So that again a full range driver and would need proper crossover to work well with other drivers. Note beats drivers looks same.

 

[hellfire8888]

 
There are Chinese equivalent of TWFK which are 10 times less expensive. Less than 10$ for pair.

I guess you are referring to a replica or fake drivers....but if i were to diy a custom iem with real Knowles TWFK driver then it is costly.

 

[ForceMajeure]

We are getting of topic here but yeah no one said it is really cheap to make, simple cost check for materials and labour IMO (I could be wrong) is around 180-240$ with knowles drivers.
As Muzo2 the implementation is key especially with DD inside.

 

[bhazard]

  We are getting of topic here but yeah no one said it is really cheap to make, simple cost check for materials and labour IMO (I could be wrong) is around 180-240$ with knowles drivers.
As Muzo2 the implementation is key especially with DD inside.

I like the fact these are being attempted with real Knowles BAs. I think these companies can learn a lot from of our feedback and provide measurements before purchase.
 
Things are only going to get better with community input, which I'm sure they will highly appreciate coming from us (free r&d). 

 

[TwinACStacks]

Not really a red flag, tbh. Most of the tuning is done mechanically, e.g filters and the like. Without the major dip at 1k, these would probably sound quite good. My guess would be an issue in phase from the DD. You could solve this by adding a low-pass into the mix, but only to lift the DD freq-range till it's in unision with the first BA.

Wouldn't this limit the crap out of the Sub Bass extension of the DD?
 
Or am I misinterpreting Low Pass Filter?
 

TWIN

 

[FUYU]

Wouldn't this limit the crap out of the Sub Bass extension of the DD?

Or am I misinterpreting Low Pass Filter?

TWIN

Nope, a low-pass elimitates all frequency above the target cutoff, while the rest below is unchanged, hence low-pass. By the way, the crossovers used in IEMs are almost all first-order ones.
Crossovers, while identical in logic, work slightly different for IEMs compared to regular speakers. The drivers are less specified in freq-range, as most stuff is fairly wide-band. There are exceptions of course, but these are way more uncommon (In case of BAs). At the crossover-points, you want to have a low degree of phase-variance from one driver to another (-180° to 180°) as this is the root of these valley/dips and most of the incoherence in multi-driver setups. (Ideal would be 0/180° or perfect phase)

In the case of the QT5, ideally you can push it to be a 3-way crossover with one for lows, mids and highs, as there is one DD and two dual BAs. But in terms of pure soundquality, this does not so much for the IEM itself.

 

[bzfrank]

Sounds reasonable. But looking at the frequency graph it almost look like the phase of the DD is 180 degree to that of the next BA. Attenuation alone would not produce such a sharp drop, neither are the BAs so limited in range.
 
 
 

 

[FUYU]

Sounds reasonable. But looking at the frequency graph it almost look like the phase of the DD is 180 degree to that of the next BA. Attenuation alone would not produce such a sharp drop, neither are the BAs so limited in range.

I was also thinking that. Maybe they flipped the phase-offset by wiring it in reverse. Like I mentioned, BAs are usually full-range or atleast fairly extended on their own. However, I can't really judge the wiring and schematics by just looking at the provided pictures. Just guessing at this point.

 

[bzfrank]

Well, guess I will toss a coin by sunday, head - they will go back, number - I'll open them up and tweak things until they sound good.
 
Are the tubes glued or just firmly pressed in?

 

[FUYU]

Well, guess I will toss a coin by sunday, head - they will go back, number - I'll open them up and tweak things until they sound good.

Are the tubes glued or just firmly pressed in?

There are no tubes. :rolleyes:
http://www.head-fi.org/t/808607/lightbox/post/12656926/id/1656044

This is a case of non-tuning in the most literal way.