Adding an amp to stock headunit using high level inputs

[tehsumo]

I just bought a 2010 Aveo, four dour auto transmission, and I like the head unit overall, but I would like a little more bass. I have a 12" Pioneer TSW sub (400watts rms @4ohm) that was used in my old car for about a month before the cheap amp gave out. Anyways, I am used to using RCA inputs and a aftermarket head unit so this is all new to me.
I decided to get an amp with a wiring kit as well, something small and cheap:
Dual XPA6100 600 Watt Peak 300 Watt RMS Mono Block Car Amplifier+8 Gauge Amp Kit (827204103142) | eBay

The amp says it has high level inputs, and it look like a five pin connector comes with it for L+-GND-+R. So my questions is, will I just splice into the rear speakers and add a ground connection, or will I have to do something different. If I go with the high level inputs will the sound quality be terrible? Should I just spend the money and get the high level converter to RCA?

Last question, where will I get the remote wire from?

[protomorph]

You should use a line output converter and wire it into both rear speakers they work great and give the rca output. Fierce Car Audio

[festersays]

^^ bingo. if you don't use a line output converter... for the remote wire, any constant power source will do the job. just use a fuse tap or something, hook it up with a cigarette lighter and it'll work for you.

[tehsumo]

So any 12v source will work? Is the cig lighter on at all times like some cars or in the aveo does it only turn on when car is running on in ACC?

[paulsaveo]

by using any type of high end converter, the sound quality will be sacrificed. the best option to maintain or even increase sound quality wuold be to use some type of sound proccessor (something along the lines of the JL Audio clean sweep), they are used to tie into a factory radio but allow you the functionality of an after market readio , such as RCA connections.

[protomorph]

a sound processor seems a bit expensive for an aveo install. that would be perfect for an expensive car that already has a good factory radio or a radio that cannot be switched. at that cost it would be better to buy an aftermarket radio.

that line output converter will do you just fine for low cost. for the remote wire the cigg lighter should be a good fuse to goto since it is a switched power source (at least it is in my aveo). you dont want a constant as that will leave your amp on to drain power while the car is turned off.

[limcooo]

for the remote wire you should use the factory radio (Car Radio Accessory Switched 12v+ Wire: Yellow) wire