Amp wiring question

2012 Tacoma Double cab. Having some confusion on wiring in my amp and sub setup. I got a great deal on the setup on facebook marketplace and couldn't say no. Here is what I started with.
I bought an amp wiring kit from skar audio, 4ga wire. Two 10" Kicker subwoofers, and a Pioneer amp. The amp has a speaker level input.
I have run the power cable, the speaker wires from the subs to the amp, and now I am trying to wire into the factory head unit. I'm not very experienced with wiring and electrical so this is a new project for me. My question is, do I need to get a line output converter so that I can connect the RCA cables to the amp? Or do I use the speaker wire to use speaker level inputs? I am really lost with all of this.

 

This may help

https://www.pioneerelectronics.com/StaticFiles/Manuals/Car/GM-5500T_OwnersManual071211.pdf

From what I can tell your amp will except one of two types of inputs from your deck. High (speaker wires) outputs and RCA.

 

Will the line output converter sound worse than the speaker inputs?

 

Anytime you're dealing with deck amplified signal and wanting to amplify it. You can have poorer sound quality. A deck with stock RCAs takes that signal before it's amplified making for a cleaner signal to be amplified. You could try each way and choose the better sound. Base only so sound quality may not be effected as much as full signal being used.

 

First off, are you using the factory deck or aftermarket? If aftermarket, put the RCAs from the sub out in the deck to the inputs on the amp and use a test tone to set gains with a multimeter. If using the factory deck, you need to make a decision first. Do you want to add a line out converter, or run from the speaker output to the speaker in on the amp? Line level is another possible failure point in the future, but does make install easier. If using speaker level, tie into the front speaker (left or right), because the rear speakers are tuned to output lower and cut off at a higher frequency. Easier to tie in behind the deck, instead of feeding the wire through the boot on the door.
Lastly, I mentioned setting the gains. Get a 50Hz 0db test tone off the JLAudio website, put it on USB, loop it, and set the gains for desired power output from the amp.

Simplified, but the jist of it for you.

 

As a former car audio and security installer, a line level converter is the way to go. You can connect it and hide it behind the radio then run the RCA (low level) to the amp. If you ever decide to install an aftermarket radio the RCA's will already be there for you. Usually you get more adjustment on the input/output of the line level converter than you do if you decide to use the high level ins on the amp itself. Also don't worry about sound quality difference whichever route you choose because subwoofers outputs are low freq enough that sound quality differences are not perceptible.