Hi all, I purchased an early SL55 (2003 with the stock fibre optic setup) that already had the head unit upgraded to a Pioneer SPH-DA250DAB:
https://www.pioneer-car.eu/eur/products/sph-da250dab
This has been paired to an amp that replaces the original Bose amp:
https://www.garsonamai.lt/en/amplifi...amplifier.html
As well as crossovers that have been wired up:
https://www.kenwood-electronics.co.u...FC-P707/?view=. (this link is for the entire kit but I only have the crossovers pictured)

So far it all makes sense:

• Headunit to amp
• Amp to crossovers
• Crossovers to speakers

What I can't get my head around is the stock subwoofer, it's currently wired up directly to the amp but it doesn't seem to be working at all - it's as if it's disconnected but I've checked and it's definitely connected!

Any idea why it wouldn't be working? - do I need a separate amp to power the subwoofer?