Tuning: Bass: 20% Mids: 45% Treble: 35% Tech: PRaT: 25% Timbre: 30% Dynamics: 15% Imaging/Depth/Soundstage/Background: 30%

The nozzles (and shell btw) optimized for same sound performance. Another problem is that got same performance at universal shell not easy as custom shell. Prelude is not an easy thing to manufacture, but universal shell needs more effort.

It is filled by a rule, but not fully.

Dryer is better for eject excesive moisture from sound tube, damper and driver. But for UV light, i can not guarantee. At hearing aid UV light sterilizing but CIEM it may cause deformotion. Because UV light changes polimers moleculer structure so a fast aging occur. edit: I can say that for...

No, focus on connector. I mean the 4 pin connector used before the patent date. So there is no protection on connector. (Still not sure :) )

As I remember UM used 4 pin connector before(not sure, platform pp6) http://theheadphonelist.com/ciem_review/unique-melody-pp6/

As i understood from figure, seal zone between two dashedlines, not whole earmold.

in ear canal isolation effected 2 ways;(IMO) First is leakage, tight fit better isolation, and elastic material also. second is surface mass density, this is used more in noise control of buildings, but priciple in ear probably similar(in my prediction)...

, seal zone can be seen

At those sizes, sound waves behaves like fluid flow in a pipe more than room acoustics. The reason for that is huygens priciple; If wave lenght is longer than gate(in iems, it is tube diameter), the gate behaves like source and direction before the gate is lost effect (so wave becomes non...

https://www.amazon.com/High-Performance-Loudspeakers-Martin-Colloms/dp/0470094303 https://www.amazon.com/Springer-Handbook-Acoustics-Thomas-Rossing/dp/0387304460 brick type document :)

For measurements; Here are some interesting pages from the Colloms book about assessment of sound. It is directed at speakers, but still applicable to iems. The main topic is what part can be attributed to measurements, and what part to objective evaluation, and how to combine both. The next set...

Hi; Your understanding of mechanical side is so rudimentary to think logically. But I want to add some words from my point of view. At dynamic system modelling, there is 3 types of elements; Mass, spirng and damper.(all ideal case everthing are rigid objects) At damping case behaviour a bit...

To making more concrete the my idea; At DAC stage, in the best case there is a speed and signal quality can produce. After that level, your signal out will remain same. For my opinion some thing also has DAC, amp or CIEM. I suspected from slew rate of DAC, resulted frequency...

If it will be wellcome, I want to comment about aliasing; In my thoughts for very high frequencies, which caused by transients not only limited by digital parts but also analog side and mechanical side is critical for that, in fact all parts affect this response. I do not know which one...

@piotrus-g yes there is not strict true ot false, but there is some big mistakes and bit tricks. Not only iem, all areas of engineering :) just know principle, and solve problems. Yes my approach is differant from you but your approach give me another point of view ;) I asked the time needed...

@piotrus-g I saw some designs, it is a good chance to see a commercial designers design :) Very interesting and also very different XO approach than mine :)   Those are good example for me. out of topic: How much time do you need to develop a commercial XO or design?

@catoval55, @gnomen , that beetle is mine As I explained, Hugo and TP are special for me.

@Jeff Y The cheapest thing on that table is VW beatle,   @RubenV In pricewise, both price is similar. In soundwise Hugo sounded better maybe much better, there is a good resolution gap and hugo has also more natural and has better black background, which is big surprise to me. Because TP has...

A shoot from my office. Tera player, Hugo and Volkswagen Beatle (1976,1/32), and some pens, pencils.

If there is no shift on mean voltage there is no need for coupling cap, when I make a diymod, ı did not use coupling cap. coupling cap be used for to be safe side. You can try it with cheap earbud.   Are they for resevoir, or signal passing on that. It looks signal passing on that for...

Did you try by-pass the caps, just short circuit? If there is no shift on base voltage, it will be good.

Here is a EQ for PG, I hope you will like.

Haha, I should have known   But my opinion is different from others. I am an old school boy. To my opinion old machines( generaly) work better than todays sophisticated technological machines. For example, old coal fired powerplants( as I saw from my technical inspection) are working more...

What do you mean by obsolete armature? 2359(?) still producing.