Where to find Stereo Amplifer to install Crossovers.

[saf98]

So i have spent the weekend installing new speakers on my polo 9n 08.
I have had many problems with this, especially drilling out the rivets.
Now i bought JBL Stage 3 6.5inch speakers that are component.
I got the tweeters installed by removing stocks and splicing new tweeter to with the harness on which will clip into the A Pillars just like OEM.
Now onto the door speakers, the speakers are connected with the harness just like these: https://www.halfords.com/technology/car ... 76154.html
The woofer is connected to a wire harness which seems to be coming from the tweeters or if im wrong the amp wire.
To install Crossovers it needs the INPUT Amp wire from the stereo, however even with unwrapping the speaker wire loom i could not find the amp wire spliced onto it?

So the question is where is the amp/input wire?

[Maarten]

From original radio, there are 2 wires per side set
So 8 in total if your car has rear speakers from factory.

So IMO the wires for (i.e.) the left front are used for the LF tweeter and the LF woofer

[saf98]

Right so they must be fuses together to power both of them right? The issue is where is it crossed over? On some video guides say mk4 golf it can be found in the door panel wrapped hidden in the loom tape which all is need is to cut off and extend to crossover.
However, for the 9n it's just two wires that connect in parallel.
See attachment, I have removed wrapping tape as much as I can.