[kaixax555]

I believe the BA200 doesn't have a crossover because it doesn't need one. Crossover circuits are usually low pass and high pass filters that sends the specific signals to the desired BA. But for BA200's case there is a specially machined plate that acts like a mechanical crossover, which is a special feature of the Acupass driver, thus no crossover circuits.
 
The Y-splitter only contains circuitry that controls the impedance, so not something particularly worrying.

 

[kaiss3r]

  I believe the BA200 doesn't have a crossover because it doesn't need one. Crossover circuits are usually low pass and high pass filters that sends the specific signals to the desired BA. But for BA200's case there is a specially machined plate that acts like a mechanical crossover, which is a special feature of the Acupass driver, thus no crossover circuits.
 
The Y-splitter only contains circuitry that controls the impedance, so not something particularly worrying.

 
Thanks for clearing that up kaixax555. I thought every multi-driver earphones has to use a crossover circuit to separate frequencies. I didn't know such Acupass technology exists. Did TDK mentioned this before? I was able to find details about Acupass technology but couldn't find any BA200 reviews nor their old websites mentioned about this.

 

[aiaosu]

Thanks for clearing that up kaixax555. I thought every multi-driver earphones has to use a crossover circuit to separate frequencies. I didn't know such Acupass technology exists. Did TDK mentioned this before? I was able to find details about Acupass technology but couldn't find any BA200 reviews nor their old websites mentioned about this.

Acupass is actually a product of Sonion that TDK utilized. There are other iems that utilized the same drivers but without the impedance correction in the cord. I've never seen the impedance circuitry on a cord except for TDK. The Sonion website explains the Acupass pretty well...I remember reading about it when looking for replacement filters.

 

[kaixax555]

   
Thanks for clearing that up kaixax555. I thought every multi-driver earphones has to use a crossover circuit to separate frequencies. I didn't know such Acupass technology exists. Did TDK mentioned this before? I was able to find details about Acupass technology but couldn't find any BA200 reviews nor their old websites mentioned about this.

It was mentioned in some of the review websites, and I also have a broken BA200 which reveals the Acupass driver. I don't think manufacturers would want to tell you what they use in their earphones, so it is pretty much up to the community to reveal what is inside the IEM.

 

[Rdwng1975]

Looking to buy a TDK BA200. Please PM me. Thanks.

 

[azattarj]

Anybody still using these IEMs?

 

[earplug]

Anybody still using these IEMs?

Unfortunately, not me. The sound on mine ended up cutting out on one side. They were one of my favorites too. I loved the isolation and sound signature. Is there anything similar out there?

 

[kaiss3r]

Anybody still using these IEMs?

Mine is still alive and kicking. Still my main earphones until now. However, the extension cable already died on me so I'm already using different cable.

 

[Silver]

Who would expect I jump to the Westone bandwagon

Westone 2, UM2, UM3X...