[Ja'Crispy]

LC2i would be your absolute best bet in my opinion if all you are looking to do is add a sub. They can be had fairly cheap on Amazon/eBay and would produce much better quality signal than a traditional line out converter. Your factory speakers will operate as normal while the LC2i generates a signal for the subwoofer amplifier.

Yep, Find it cheap on Amazon (sold and shipped by Amazon) and Crutchfield will price match it, full warranty intact w/free shipping. I saved a significant amount of scratch going that route when I ordered my system.

Side note about the factory system and adding in a sub. I will say that the factory DSP settings of the headunit for the base model sport, suck. I haven't done a frequency analysis yet, but I can easily tell they have a steep roll off high-pass filter at 40/50Hz. This moves higher as the volume climbs, so set your input gain higher on your amp and tune your headunit for max gain at no more than 32/33. It does not play well if you are looking for good capture of sub-harmonic frequencies. Sure, it will bump, but if you're after SQ - an after market head unit is a must. I haven't upgraded mine yet, only because I haven't found one with a GUI I like. I am not sure why aftermarket touch screen manufacturers always have such terrible user interfaces. Everything is touch screen these days, why does car audio/video still look like it was built in the 80s? Lol... I love the UI on the stock system, just hate the DSP settings.

 

[Ja'Crispy]

What about the use of something like this https://www.jaycar.com.au/speaker-high-level-to-line-level-converter/p/AA0482

With taps, then I'm assuming that the speakers I've tapped will still work as per normal, and I get RCA out to connect to the amp? I am quite keen to use the Pioneer unit I linked earlier.

Something like should work - on paper. I would be hesitant to put something that inexpensive in line. If your route is to convert the signal pre-amp, I would go with this.

https://www.crutchfield.com/p_161LC2IB/AudioControl-LC2iB-Black.html?tp=70736

 

[Ja'Crispy]

So I ended up buying a self contained sub/amp combo to try and install, one of these bad boys. https://www.pioneer.com.au/shop/car/ts-wx120a/

The spot behind the centre console was a PERFECT size, slightly raised by really flat thanks to the car being a front wheel drive, excitement was rising.

So I pull the dash apart and get the deck slid out and it has neither of the two connections this unit needs to connect (Speaker line input or RCA input).

Looks like if you have the base 7" unit / 6 speaker system, you're plum outta luck trying to add a subwoofer to that setup, unless someone here knows a good solution given what I've said? Here are some pics of the back of the unit.

You will need an amp with speaker level inputs, then need to use taps to split off the front or rear speaker outputs from the head unit.