I'm in the middle of installing a Rockford P300 in my 2017 IS200T (no Mark Levinson).

The instructions that came with the subwoofer indicate that the RCA cables have to be connected this way (and set the amp to High Level Input):

• White to Left + (Peach on the OEM amp for the left rear speaker)
• White/Black to Left - (Pink on the OEM amp for the left rear speaker)
• Grey to the Right + (Light Green on the OEM amp for the right rear speaker)
• Grey/Black to the Right - (White on the OEM amp for the right rear speaker)

Do I tap into the rear speakers on the amp directly?

Or can I do the following since the amp has a Low Level Input setting as well:

• White to Left + and Grey to the Right + to the Gray wire on the OEM amp (positive on the OEM amp for the subwoofer)
• White/Black to Left - and Grey/Black to the Right - to the Blue wire on the OEM amp (negative on the OEM amp for the subwoofer)

I see a lot of people using a LOC, is this necessary for this subwoofer?

Thanks in advance!

 

You have instructions, follow them.
Tap into the harness at the amp.
Low level (or line level) and high level (or speaker level) are two different input signals, you want high.
A LOC is needed for amplifiers that don’t have high level input capabilities.

 

Worked with the subwoofer wire.

I asked since this subwoofer has been around for years and I'm guessing they didn't take into account cars that come with a subwoofer.

 

Glad it worked out. And you’re probably right, they recommended those speaker wires for cars without factory subs.