About MFxLMS active noise reduction processing

Hello:

I am currently working on the active noise cancellation function implemented with MFxLMS, I want to achieve the goal of reducing the noise inside the car through this filter, but I encountered some problems.

For example,why is there a particularly loud noise in Secondary Path Training?

How long do I need to train to stop?

And how do I know if the training was successful?

Here is my engineering schematic and MFxLMS's filter parameters.

Engineering documents: MFxLMS滤波.dspproj

English is not my first language, some expressions may not be so easy to understand,I apologize for the trouble caused.

I use number 1 as reference noise signal and number 17 as error signal.In addition, I used a microphone on number 0 and 1 respectively.Number 1 mic is used to receive noise from a white speaker,number 2 mic is used to receive noise from this black speaker(output 0).

Diagrammatic sketch:

When everything is ready for me, I choose Secondary Path Training and press start ,the black speaker Make a very noisy sound ,even if I didn't make any sound from the white speaker.

Like this: