Stereo system upgrade infor for 01 Pathfinder

[mda185]

After writing this and posting it, I thought it might be better to introduce myself first. I am kinda new to this forum and have not posted a lot. I am a 52 year old father of two and die hard DIYer. I have been modifying cars and stereo systems since 8 track players were the preferred upgrade path in factory stereo systems. My 01 Pathfinder is my second one. I also owned a 94 that I drove for about a million miles. The 01 is my family car. My other rides are a 92 Celica All Trac Turbo, 97 BMW 328i convertible, and 95 BMW 525i wagon. All have between 100-200K miles on them and I do all repair and maintenance. I don't know how many DIY folks are on this forum so I am looking for feedback on this post. The more interest there is, the more in depth info I will post.

I have posted some of this information to other threads but I think it is better to start a new thread and post pictures as my build progresses. I have a 2001 Pathfinder that came with the Bose system. In a word, the system in my Pathy sucks. The CD player is prone to jamming, the speed sensitive volume control isn't, the bass & treble responses are rolled off, and the tuner is not very sensitive. I don't know if my system is defective or if they all sound like this. It really is only good for talk radio if you like anything approaching good stereo sound. I decided to upgrade my system in two stages. The first step was putting in a better head unit. I chose an Alpine DVA-9860 single DIN DVD player. It was left over from a previous install and it is a decent performer. The main reason I bought this head unit is that it can control the Alpine H701 digital signal processor, it has an optical output, and it was on sale for about $250 at the time. There are better head units on the market but this was a good deal.

There was a problem with the Alpine. It only has a 2 volt preamp output and I wanted to use it initially with the Bose amplifiers and speakers while I figured out the rest of the system upgrade. 2 volts is not enough to drive the Bose amplifiers to reasonable output levels. They are designed for a 5-6 volt balanced signal from the OEM Bose head unit. There are two ways around this. I could have used the speaker level outputs from my Alpine head unit but this frequently results in a noisy signal. I did not try this in my install. I wanted to add some equalization capability and an aux input for my Sansa Fuze. I had an old Precision Power PAR-225 half DIN preamp that was perfect for the job. The PAR-225 was made about 15 years ago and it was a high end piece back then. It is still a very good performing piece of equipment and you can find them on Ebay and audio forums for $75-100. There is also a PAR-245 with similar features but no Aux input. I wired the preamp output from the Alpine to one of the inputs for the PAR-225. The front and rear outputs of the PAR-225 are wired to the preamp level inputs for the Bose amplifiers. Metra sells a Nissan Bose wiring adapter that makes this easy. The sound quality of the Bose system was improved tremendously. The bass response is far more extended and tight compared to the OEM Bose head unit. The treble response is much clearer. Now, the system limitations are in the Bose amps and speakers. That is the next stage of my system upgrade. Here is a picture of the Alpine HU and the PPI preamp in my dash. The gap in the middle has been filled with a plastic tray since I took this pic.



Next up, I will start upgrading the front door speakers and install high power amplifiers in an rear mounted amp rack.

Modified by mda185 at 4:57 PM 11/4/2009

Modified by mda185 at 7:06 PM 11/4/2009
Modified by mda185 at 7:12 PM 11/4/2009

[K03sport]

Sorry to bring up a thread from 2009, but I recently installed a JVC KW-R920BTS and my bass seems to have disappeared. I used the harness from scoche, but it uses the speaker level signal to go to the Bose amps. How did you get the signal from your PPI pre-amp to the Bose amps?

Was it Line Level (RCAs)? IF so, how'd you do it?

The JVC has 2-4V RCA outs on the back.

Thanks again...I know this is an old old thread.

[Jake2.4]

metra 70-7551

[K03sport]

metra 70-7551

Thanks for the reply and pic.

dag-nabbit....I was not supplied that particular harness with my Crutchfield order. They included the Scosche one that used the line level (speaker wires) instead of RCAs [p/n 142C4NN03 (http://www.crutchfield.com/p_142C4NN03/ ... 3&skipvs=T . I know one harness has the 12v/switched/illumination, etc, but that same harness (the bigger one) also has front L/R speakers in it as well.

The smaller harness has the rear channel and a few other wires.

I have a few PAC boxes that convert line level to RCA but I hate to hack up the wires behind the HU again, plus I don't think the front amps use RCAs...or do they? Does the rear amp use RCAs? I haven't dove into the inner guts of the PF; I just don't have the time.

It works; it took a while to do all of the soldering, and in the end I had sound with out issues...just not the "right" sound IMO. I'll keep researching and see what I can find and I might even end up call Crutchfield tech support to see what they have to say.



I spent about an hour tweaking all the Audio controls/x-overs/freq cut-offs and other EQ settings and I think I have it better but not as deep or loud as the factory HU would get.

Maybe the Bose system is not friendly to outsiders and because Bose artificially boosts low frequencies anyways, taking away the factory HU to away the artificial boost.

[K03sport]

Update/Edit:

They [Crutchfield] included the Scosche one that used the line level (speaker wires) instead of RCAs [p/n 142C4NN03 (http://www.crutchfield.com/p_142C4NN03/ ... 3&skipvs=T . It works; it took a while to do all of the soldering, and in the end I had sound w/o issues...just not the "right" sound IMO. I'll keep researching and see what I can find and I might even end up calling Crutchfield tech support to see what they have to say.

After doing some research on the Metra 70-7551 and reading reviews on the Crutchfield website, it may appear that the Metra 70-7551 causes some issues w/ popping when connected to an aftermarket stereo. lnik: http://www.crutchfield.com/p_120707551/ ... N&skipvs=T

So, in the end, it may appear that the Scosche 142C4NN03 might be the better option w/ the JVC HU I installed, despite it having 4V pre-amp outputs on the back. I will continue to tweak the system as necessary, but I will need to pull the HU again if I want to adjust the gain level adjustments on the "CNN03" adapter.