Balanced armatures are bad in price and performance as a transducer compared to dynamic drivers.

Disagree the ER4S has a clarity that DD barely can reach. Pointing out the THD noise is kinda silly when DD has it flaws like coloured sound vs other driver types. There a reason why the best IEM are BA rarely DD.

Multi driver IEMs have many areas of QC issues such as crossover network, frequency response variance, tube lengths and the general high cost of balanced armatures.

That also why multi driver still struggle with coherency issues.

Expensive CIEMs are a waste of money and a joke. Higher driver counts are marketing and I wouldn't be surprised if Knowles and Sonion are being pressured into making unnecessarily small versions so the driver count can be inflated.

Never understood the multi driver craze, You have the IE80, E5000, EX1000 for good single DD & ER4S for a really good single BA.

Yeah i necro'd.