Using rear channel wiring for front speakers

Sorry, I don't have the answer, but I second your question. I am considering upgrading the JBL with something like Cleansweep and another amp, but would like to skip the expense/step of combining the front signals while retaining Nav/Phone sounds.

Anyone with ideas??

 

You will lose nothing by tapping the rear channel speaker outputs to drive an aftermarket amplifier, as long as you continue to use the stock speaker wiring. That is how I've wired my 2005 w/JBL. The nav drives the front left speaker directly by disconnecting the audio signal and connecting itself to the speaker. You would only lose the Nav voice if you ran your own speaker wire.

 

1) The point where the nav voice switches itself in is downstream of the amp. That's why I wrote "The nav drives the front left speaker directly by disconnecting the audio signal and connecting itself to the speaker." If it was upstream of the amp I would not have written that it connects itself to the speaker. Therefore it does not matter what you do with your amp - you could cut all the input signal wires and all the speaker wires at the amp and the nav voice would still function.

2) You lose fader control. In a high-end audio install you only care about the fronts anyway. Utilizing the rears for anything more than fill ruins what little imaging and soundstage a car audio system is capable of producing.

 

Yes. It's clear when you look at a wiring diagram. The speaker signal from the amp actually goes through the Nav system before it goes to the speaker. This give the Nav system the ability to disconnect the amp output from the speaker, and drive the left door speaker itself.

That's what I have, except I used a four channel amp, and send four channels of amplified signal from the amps in the trunk forward to the passenger seat, where they connect to the stock speaker wiring to carry the signal to the speakers themselves. Crossovers for the front speakers are under the passenger seat, since with the JBL amp, woofer and tweeter for the front are driven separately from the amp. Crossovers for the rear speakers are mounted in the doors (since only a single pair of wires goes from the area under the passenger seat to the rear doors).

Mutes and beeps are preserved by keeping the JBL amp (you can amplify its outputs, but you need it to generate the beeps, and mute the speakers). Nav/Bluetooth phone output is preserved by keeping the stock speaker wiring going from under the passenger seat to the Nav (and eventually the driver door woofer).

 

What wiring diagram?!? I've been trying to find a diagram for months... where do I look?

 

The following information is correct for 2006+ models only. It does not apply to the 2005. Thank you Priusenvy for calling this to my attention.

Hey guys, I think you may be making an incorrect assumption about how the "premium" sound system works.

It is true that the rear outputs from the JBL amp under the passenger's seat are full range. If you do not have bluetooth or nav, using the rear outputs to drive your whole system--front & rear--would work. Quick and simple.

If you do have BT & nav and wish to hear their signals, these are only available on the left front output of the JBL amp. (The JBL amp performs several functions including system volume control, fading, muting and mixing in the BT & nav audio.)

The only way to preserve the BT & nav audio is to capture it at the left front output of the JBL amp. Since the front outputs are for bi-amp configuration--two outputs per channel, high frequency and low frequency--and you intend to install speakers using crossovers, the high & low outputs need to be summed to drive your after market power amp.

To combine these outputs you need a summing device of some type. There are simple and complex ways to do this and I've written extensively about it in older threads. Check this one out:
http://priuschat.com/forums/audio-e...pgrade-jbl-premium-speakers-4.html#post496309

Good luck and have fun with your Prius.

 

That is not correct, at least for a 2005 w/Nav, and I suspect it is not true of later models as well. I am only utilizing the rear channel outputs of the JBL amp (all eight speaker wires to the front have been CUT - the front channel outputs of the JBL amp are connected to NOTHING). I still have Nav voice and Bluetooth phone coming out of the left door mid-woofer, and that is because I preserved the stock speaker wiring to the left front door. It has nothing to do with preserving the output of the left front channel of the JBL amp.

That is just flat out wrong, at least for a 2005, which is what I and the OP both have. As I wrote before, if you look at the wiring diagram, you see that the left door mid-woofer speaker signal goes into the Nav so that it can control who's driving the speaker. It has nothing to do with the JBL amp's front channel output, and everything to do with how the speaker wire is run from beneath the front passenger seat to the left door.

 

A four channel amp will usually have a switch on it for two-channel input or four-channel input. Mine has a switch. If it didn't have one, you could use a Y-connector, as the inputs are high-impedence, and can be safely driving in parallel. So yes, I am avoiding the need to sum the front channel woofer and tweeter signals, at the expense of losing fader control on the head unit.

You still have front-rear fader control by adjusting the gain controls for the front and rear separately on the amp. It's just really inconvenient, so you pick a ratio you think you can live with and forget about it. Works for me. My rear speakers are some Infinity components - I don't feel a need to upgrade them, even though the Diamond Audio speakers are in a whole nother league. I really like my Diamond D661s speakers - I think they can give any speaker under $800 retail a serious run for their money.

 

Oh, I missed the 2005 reference. :redface:

Sorry for the intrusion and my inaccuracies.

 

Are you sure the 2007 is different? I'd be surprised that they'd make that big of a change in how things were wired between model years. You're telling me that if you yank the front channel inputs to your amp, you lose Nav and Bluetooth? Like I said before, on the 2005, retaining Bluetooth and Nav only depends on keeping the stock speaker wiring, not on any signal into or out of the amp.

 

Yes, I was just referring to the Nav voice and Bluetooth audio itself, not the beep or muting functions.

 

Yes, because the rear speaker output of the JBL amp feeds my JL Audio CleanSweep, which then feeds two channels into my four channel amp, which is then hooked back up to the stock speaker wiring.

 

where did you hook up into your speaker wire? at the speakers? in the dash?