See, this is why this wont work in my particular application...
My DSP requires a full range signal, im not simply adding a subwoofer and calling it a day...if this was the case, I would be booked in with you and getting the subwoofer output enabled on the MMI lol
What DSP's require are a full range signal, they need to see the whole frequency bandwidth...once it sees this, it can split up the frequencies as required - send 4khz upwards to tweeters, send 150hz - 2khz to the midrange, send 50hz - 120hz to the midbass, and 50hz and below to the subwoofer. This signal can also be EQ'd flat, and tailored to meet your musical taste (ie if you like a flat neutral sound, or you like it crystal and sparkinling on the top end, if theres too much mid you can remove it etc), as well as time aligned, phase shifted, and filtered
What I am interested in trying though, is using the front speaker inputs in to the DSP, for my full range signal for front and rear channels from the DSP, and then use the subwoofer high level outputs from the headunits to feed into my DSP to feed the sub...however this then throws up an issue if the signal is filtered which is usually is below 30hz or so which isnt low enough lol...
This way, we will be able to use your coding, retain the stock subwoofer control on the headunit, and still add all the external amps in the world and uprate everything...but if the signal is filtered, then it will be a no go. From all of our previous cars and installs, the stock headunit filters the signal on the bottom end
Worst case we need to add a RCD controller which isnt the end of the world and would look pretty smart too