Sub installation: line in to amp??

[krooster1234]

I'm going to be installing an amp/sub in my 2004 prius, which has the JBL system. I have one question though:

What are my options for signals that I can run into the sub amp, and where are these signals easily accessable?

I've done searches of this forum, and the only example I found where someone gave specifics is where their installer used some sort of device to convert the signal going from the JBL amp (to the rear woofers) into a pre-amp signal.

I was hoping there was an easier solution.... like access the signal going from the head unit to the JBL amp, and wire it to the amp for the sub??

Basically, I just want to know what kind of signals an aftermarket amp can take as their input, because I know you can't simply take the line out of the JBL amp and use it as the line in to the sub amp.

-Kevin

[HTMLSpinnr]

The line-in for the amp is a shielded 4 conductor wire. The receiver only outputs 2 channels, and fade and balance (and possibly volume) appears that it could be handled at the amp itself via an ACV-LAN connection (which btw, kills anyone's idea of putting in an aftermarket amp). There are also 2 mute lines - one for the NAV and the other probably for the head unit itself.

The line-in connection at the amp colors would look like:

Common Shield connection
Left (-) = Black
Left (+) = White
Right (-) = Green
Right (+) = Red

Because this is not faded - and possibly not volume controlled (fixed output), it may not be a reliable source for input. Also, we don't know the impendance or voltage of the line-out, which may or may not match your sub amp's requirements.

Although it's not the best option for fidelity, I'd opt for the speaker-to-line converter off the rear speakers simply because I would know it's post-modulated (volume, fader, etc.). And given that it's a sub, I wouldn't be worried about killing high-end fidelity.

For those with techinfo access - grab the "Multi-Display and Audio System with Separate Amplifier" file and you can have a better understanding of what I'm talking about. Filename 052mdass.pdf. This file also shows how it connects to the multi-display unit (screen) and whatnot.

For those without, I've taken the liberty of taking some screen-shots (PNG format) of the 2 pertinent pages - Danny if this isn't kosher, feel free to pull them. They tell way more than I can describe, however the connections displayed are not all-inclusive.

Enjoy!

[krooster1234]

Thanks for the excellent info.

Also:

Does anyone know for sure whether or not the line into the amp is volume controlled, or whether the volume control takes place in the amp? Using the signal going to the amp would be preferable, if volume control is possible.

Does anyone know if I can just go into an audio store and ask for a "speaker to line converter", and they will be able to sell me one? Do I need to know any specifications of the amp to find the correct converter?

[finman]

Can't answer the 1st question, I have the #7 non-JBL stereo...but the second I can. Sure, the device you're looking for is commonly called a line-out adapter. It takes the high-level speaker signals (say, from a head unit or even right from a speaker), then lowers it thru circuitry to 'amp-level' signals, which an aftermarket amp likes much better. I don't believe there are any specs one has to know to do this. Also, get the best u can afford, helps in a clean solid signal with minimal loss. I'm hoping to add a sub to my basic system someday, running the rear speaker signal thru a line-out adapter and into a sub amp. Got to have more bass! Love this car...