Adding sub to HK system. ANC question.

[Renegade34]

I’m planning on adding a compact powered sub to the HK system in my 2021 Sport.
I plan on tapping into the speaker wires to the factory sub (at the amp) for signal. Will I have to disable the ANC system? I’m leaving the rest stock.

 

[Brunzca]

I’m planning on adding a compact powered sub to the HK system in my 2021 Sport.
I plan on tapping into the speaker wires to the factory sub (at the amp) for signal. Will I have to disable the ANC system? I’m leaving the rest stock.

yes, you’re going to want to bypass / disconnect the ANC. Any more bass will cause noise from it.

 

[Renegade34]

I read this on another forum. Can anybody confirm that this is true? Mine is a 2021.

"If you have a 2021 you can retain ANC by using the PAC AP4 CH41 interface, which would send your sub amp a flat pre-amp signal without the ANC processing. Unfortunately from what I hear, the PAC doesn’t work in the 2022s."

 

[Renegade34]

What I don't understand about this whole ANC thing is how would it know to try and cancel the new sub if I tap into the factory sub wires for signal? The cut off frequency would be the same. There would just be more bass and I don't know how that would be any different than cranking the bass way up now.

 

[Brunzca]

I read this on another forum. Can anybody confirm that this is true? Mine is a 2021.

"If you have a 2021 you can retain ANC by using the PAC AP4 CH41 interface, which would send your sub amp a flat pre-amp signal without the ANC processing. Unfortunately from what I hear, the PAC doesn’t work in the 2022s."

What I don't understand about this whole ANC thing is how would it know to try and cancel the new sub if I tap into the factory sub wires for signal? The cut off frequency would be the same. There would just be more bass and I don't know how that would be any different than cranking the bass way up now.

The CH41 won’t bypass the ANC, the ANC is activated/driven though the factory amplifier, and triggered by sounds ”heard” by the small microphones in the headliner. The ANC has to be disconnected, or bypassed With a separate harness.

This is how Crutchfield explains it.

When you install a subwoofer in one of these vehicles, the ANC system hears the subwoofer's output as being part of the engine/road noise it's supposed to cancel out. So, it emits an out of phase bass signal to block the sub's output. When the ANC doesn't hear any bass, it stops playing the out of phase signal, and the sub becomes audible again. Until the ANC kicks in again. And on and on.

 

[Renegade34]

Ok. Thanks for the reply. Much appreciated!