Connecting Crossover on 2012 Prius C

Easy- the crossover is going to have 1 input and n (usually 2) outputs. The input is expected to be full-spectrum amplified speaker-level audio from the head unit.

The crossover is a passive filter network that divides that full-spectrum signal into two or more bands of frequencies. These component signals are then output onto several sets of wire terminals on the output side.

The net effect is better power efficiency and lower distortion. The watts you've already gots are better applied.

What it really means: The car has one pair of speaker wires going into each of the front doors. This is the full-spectrum audio. This goes into your crossover, which you should mount someplace inside the door- watch where the glass moves. Then take the high frequency output and run a wire from those terminals to the tweeters mounted up high, and run a second pair of wires from the low frequency output to the big speaker in the bottom of the door.

Very common method, I did the same in my c.

Good luck!

 

This post covers it about as good as you can.

BUT.....I think that replacing audio components in most cars in an attempt to improve the "quality" of the sound is just a waste.
Especially is a small car that has little to no design elements to reduce ambient noise.
Wind noise, tire noise, engine noise and an "enclosure" that is not "tuned" all makes for an extremely BAD environment.

 

It's been a couple of years but here's what I recall:

The aftermarket crossover is in a fancy box to make the buyer feel better about the expense- not technically required at all, thus the factory system is done in a cheaper and uglier layout, no centralized device.

Moving on... the lines connected to the large speakers are what you want. Either cut off the Toyota connector or buy an adapter to get back to bare wires. Those wires are what you want going IN to your crossover.

Then disconnect, tape-over & ignore the wiring branch going up to the hi-mount tweeters.

Physically mount your new speakers. I removed the factory tweeter assemblies, and then cut the actual speakers off from the plastic boomerang shaped brackets. Then I used epoxy glue to mount my new tweeters on the brackets and bolted the assemblies back into the door- worked great.

Then run new wire from the outputs of your crossover box to your new speakers & reassemble.

I doubt they changed much in the way of speaker wiring between your 2012 and my 2018, but it's always good to verify wire paths with a continuity tester before committing. Good luck!