Amp and Subwoofer install?

If you want to add an amp, then add an amp. as long as it can take high level inputs, you can keep your head unit.
If it can't take high level inputs, you can use a voltage divider to reduce the voltage.
No need to remove the amp under the seat.
I suspect the JBL system manipulates the frequency response when it drives the speakers. If that is the case, you
will want to be able to compensate for this with your subwoofer amp.

You might want to contact a honest professional installer.

 

Hi Quinton,

I've replaced my entire audio system and still have the old parts. The factory deck connections at the rear look like this:



There are no pre-amp outputs...even the antenna connection for AM/FM does not use the standard plug!





Hope this helps!

 

Whoops, my apologies - I didn't read your first message. My Prius is a non-JBL equipped vehicle. Perhaps the JBL equipped ones do have a pre-amp output.

As for my system, I put in new everything: My version of the ultimate stereo for the Prius | PriusChat

Good luck.

 

check out this youtube video, this is how I installed my Kicker power sub woofer.

 

I have a a 2010 III jbl with nav so the setup is different than yours.
If you replace the head unit you may lose you steering wheel audio controls. Some interface adapters work with some radios and steering wheel controls, others don't. If you stay with the current head unit you have to figure out how many channel amp it is. The reason that matters is the frequency range of the signals coming out of the radio called preamp level radio outputs. Like the other response said you have to be concerned with buying an amp that can take low level, preamp inputs if that's the case.
If the head unit has one FULL RANGE output( 2wires)per channel meaning a total of 8 wires that is great since that's how most after market amps have inputs for. Meaning that your currently installed OEM head unit has 2 wires/channel feeding 4 channels=8wires. Then you can connect those 8 wires into the new amp and your set.
BUT if your amp, being the JBL setup has the frequencies divided up by the head unit and not inside the amp, meaning NOT FULL RANGE outputs leaving the head unit,then you have a problem because you have 8 output channels coming out of your amp. Instead of a total of 8 wires coming from the head unit you have 16 going into the amp. As each channel has 2 high freq. tweeter wires and 2 low freq woofer wires = 4 wires for 2 channels/speaker pair. Assuming you have 8 speakers , that 16 wires coming out of the head unit but most OEM amps can only use 8 wires as stated above.
Jl audio and I guess other manufacturers sell summing signal conditioners (but that's an extra $400) to take the 16 wire input and convert it to a 8 wire configuration that will work with any 4 channel aftermarket amp (or a 5 channel aftermarket amp that will feed all 4 speaker pairs and a sub channel also. If you love the head unit and want to guarantee you don't lose your stereo controls, you buy the summing signal condition for $400.
But you could also put that same $400 towards buying a nice Nav unit without the need for this not so cheap $400 signal conditioner. Up to you.
My email is [email protected]. If you like email me there and i'll give you my phone number and i'll explain it to you better.
Put something in the title so i'll know its you. Hope this helps more than it confuses. I can explain it in realtime better than email.

 

I just installed my system into my Prius Wagon this week. All you need to do is get an amp with a speaker level input and tap those into your rear speakers. You dont need to go through all the hassle of removing your head unit. Run the normal remote, ground and power wires and you're all set.