Bigaudiofanat- Can you clarify something for me..? Above you said running your Bose speakers off your aftermarket headunit will fry it. What I did was get a wiring harness, but just the one that allowed me to tap into the factory wires, not convert ohm levels like the PAC unit you mention above. I am assuming that the factory wires behind the headunit are ALREADY GOING TO the Bose amp BEFORE going to the speakers, right? So, in my case, the Bose speakers should still be powered by the Bose amp. The headunit I'M using now (Pioneer X920BT) is just sending the audio source to the Bose amp, just like the stock Bose headunit, no? Am I off here?

For what it's worth, the performance of the stock Bose audio system in the Touring is at least 1000% better with this Pioneer X920BT in place. You have much better control from an EQ perspective, so you can do a better job of removing the deep guitar riffs from coming thru your highs. I'm no expert in car audio, so I'll be the first to tell you that. However, I've been installing my own car stereos and friends since 1990 and am VERY picky about sound quality.

There is one song I've used to tune my sound systems' preamps with, and it's Metallica's "Eye of the Beholder" off of their And Justice For All album. Regardless of what music you like, I recommend playing this song very loud, and you'll see whether your mids are pushing clean audio. If you quickly reach for the volume to turn it down to avoid harm, you might want to look into a preamp if you don't already have one. I know some don't like using them, but I swear by them and will never go without. But that's me. The point is that for those of you who are debating on getting rid of your stock Bose, I highly suggest you consider doing the headunit first to see how you like it as-is. I believe you'll be surprised. I will likely swap it out down the road, but it's not my highest priority anymore because I'm very content with what I'm hearing how.

So i just dropped in a z120bt into my sport touring z without the nav. I replaced my bose head unit. The harness does go to the bose amps, however, this is why you cannot directly wire your head unit to the harness. It is the bose amps that present such low impedance to the head unit. This is what will burn out your head unit. For my install i used a pac. The headunits 4x2 speakers wires (8 wires) were wired to the pac, and the pacs output wires were connected to the car wire harness. All other wires were hooked up normally.

I am pretty sure this is an accurate response, i hope Big can verify it.

^^^^ What he said.

Your new head unit gets wire to the pre inputs of the input of the bose amp than goes to the bose speakers. So this will work but you can not run wires from the bose speakers directly to the head unit, that will fry them. The best way to integrate the new head unit into the bose system is that pac unit I linked. That allows the levels going into the bose amp not to be to much to harm it.

Thanks for clarifying. I gotcha now. This morning I went to CarToys to talk to someone who has experience with the 370Z installs, and he gave me the right wiring harness for "High End Factory Systems", which does exacly what you explained. It has the 4 RCAs for the Bose Amp, and 4 wires for all the power needs. Much cleaner this way. I will say that it now sounds totally different than it did last night though. As you've probably read in my other posts about how good it sounded while running through just the wiring harness, it went back to factory sound. However, and this is a big however, once I was able to play with the loudness and EQ settings on the headunit, the bass is even more responsive than last night, tighter, and I can now raise my volume over 6 without blasting my ears out.

Thanks for the feedback on this. I'm glad I checked before putting everything back together. I'm now onto the rear camera wiring, and the install of the new pioneer XM receiver. I was able to find the factory XM antenna wire, which goes right into this Pioneer XM receiver, and then outputs to the headunit via an IP-BUS cable, which is what the X920BT was looking for but I didnt have while using the stock XM Receiver. If anyone has questions about that setup, let me know. I just spent hours researching how to reuse your factory XM antenna and am glad I did because I am able to reuse the antenna wire already run, the ACC and Battery power wires right off the stock XM receiver. Will post pics once I complete everything. I've been taking pics as I go so I have plenty, just no time to post them while I'm installing.

You mean 4 rcas to connect to your head unit? Other than that bose amps do not have rca inputs on their amps.

Yea.. i think that is what he means... I choose to use the power level outputs of my HU to connect to my PAC.

wow that's very interesting running XM to the x920bt with no adapters. I'd love to do this one mine as well.

Sorry to bring this back to life after a couple of months but just want to clear this up as much as possible...

I too have the Bose system and want to install ONLY a new HU...

So, the right connection would be:

HU ---> PAC SOEM-4 ---> Bose Amp wires

the HU brings a wiring harness.. should I use that one or am I going to need something like the Scosche NN04B harness..??

Am I going to be using only the wires that need to be split and put together or am I going to be using the RCA connectors as well..??

Thanks for the help..

Anyone please? Thank you!

You are NOT going to be able to use just the head unit. Only way to even try it is with a re-q from mtx as that may accept the low output of the head unit. BUT I have only heard that it can be done with the bose amp in tack as that is all I have done plus it is easier as well.

Just finished my HU install I have a 2009 touring with the Bose. I replaced just the Hu and kept everything else.
I installed a
Pioneer AVIC Z120BT
Pac SOEM-4
Axxssess ASWC with all steering wheel contols working
Pioneer backup camera.
Scoche wireing harness

Everything works great. It took me awhile to get everything properly installed( did some dynamating too) but can be done. Was able to fit the PAC under the HU and the Axxess to the side of the HU. tight fit all in all.

I think it sounds much better than the Bose. I have much more control over my sound stage adn my EQ settings. I would say night and day differencees in sound quality. granted I'm not the best audiophile out there, but I know what I like.. I now also have Nav, DVD. adn rear view camera
Without the PAC The volume is very hard to adjust. turning the radio to 7 would blow you out of the car. With the PAC you can adjust the outputs and the volume becomes much more controllable. I did not use the RCAs in the PAC setup. you have the choice of RCAs or just direct wire. While I had the Soldering Iron out I just soldered up all the wires.

I plan to put details of my install up later. If you have any questions jsut reply to this post or PM me

That's awesome!

Thank you very much man!

It's actually really simple to do .. Metra 70-7552 - solder Male RCA ends on in place of the speaker wire leads - plug into your new HU like you would an aftermarket amp. Done.

Although I do find humor in the retailers that 'up sell' something that you 'need' to make it work right. :)

I'm a little confused, maybe because I don't have any wiring manuals in front of me right now. Above is what I'm planning on doing in a couple of weeks, but I'm confused about how all the wiring fits together. It's always been HU -> Scoche wireing harness -> factory wiring for any previous install I've ever done. But where does the Pac SOEM-4 fit into the mix? Does it connect between the HU and the Scoche, or between the scoche and the factory wiring? Thanks for the clarification. :hello: