Hello, I have a 2023 Mazda CX-5 w/ Bose.

I want to know if there is any audio interface that can be used so that I can hook up a bass amp and subwoofer while using the rest of the stock audio system. If not what other options do I have like a line output converter(LOC) and or digital signal processor(DSP)?

Thanks.

 

You can fairly easily tap into the Bose system subwoofer which is in the spare wheel well and run a separate amp.
The issue is how the Bose system processes different sources and I'm not sure an additional audio interface will help or hinder that.
There are several online instructional video sources on how to best resolve this issue with your audio settings and how to tap into the Bose sub-woofer.
As always sound is very subjective to the listeners ear and musical tastes.

 

Lobstah ... maybe because of the year and BOSE that may not actually work well as your would think. BEFEOR you do any adding onto the BOSE system in your 2020MAZDA you should contact the aftermarket manufacture of the equipment you are looking to use and find out from them if it is compatible to use on a factory MAZDA BOSE system.
My 2018 was a PIA because of BOSE and I was using top grade stereo compontes..... working with several manufactures all over the US . At least one top very well known in the audiophile and stereo world (I am not going to post which) said not to use their products! And this all started with only wanting to add a subwoofer and encloser with its own dedicated amplifier.