In this Qudelix case is more complicated than balanced connection.. The cabling should be similar to using bi-wire cabling from amplifier to speaker.. But instead of using passive crosover inside the speaker box, with active X-over, each driver would have their own amplifier.
For example for 2 ways with active XO one channel only... (So for stereo, there will be another like this)
LPF : Low Pass Filter
HPF: High Pass Filter
source
|
actXover
| |
LPF HPF
| |
Amp Amp
| |
Low High
Driver Driver
Imagine the complexity on wiring IEM like this.. This could not be simplified to 3.5mm TRS nor 2.5mm TRRS.. It would need at least 4.4mm TRRRS.. If and only if the circuit could have common ground. But even so, the wiring would be totally different with balanced 4.4mm as we normally use..
Theoretically, with active XO, we have so much freedom to decide XO order (1st, 2nd, 3rd, etc..) and scheme (Butterworth, Linkwitz-Riley, etc.) which could result as better driver integration/seamless or we coud use it to push driver to the limit (i.e. using 6th order 48db/octave) which is very difficult to do (if not impossible) with such a small space on IEM housing..
I'd like to see how Qudelix could achieve this and whether it would worth the effort.. Time will tell.. But I really, really hope they are succesful and the result worth the hassle