power rating for after-market speakers

[tecciball]

So I have read up a bit on stereo installs in the Garage and Pinned areas and found some good info. But I have a few questions.

 

First, my Pathy is an 01 SE with the BOSE tape deck plus multidisc CD below (which broke a while back). I understand that the stock set up includes separate amps for the door speakers. Since there are external amplifiers, I assume that the stock head unit has little to no power output. I wont be adding a sub, so I plan to use the existing speaker wiring and amps. Since an aftermarket head unit has quite a bit of power ontop of the stock amps, I am concerned that the stock speakers will blow out. For that matter, I am concerned that aftermarket speakers, if not matched properly, would blow also due to the extra power. So my first question - does anyone know the power spec on the stock amps? Most new head units appear to have about 50 max watts per channel (15 - 20 RMS). Since the headunit and door speakers would essentially be in parallel, I would need to add the max and RMS specs from the stock amps with the headunit and make sure that the speakers can handle those wattages, right?

 

Second, can someone please recommend a source for the headunit wiring harness or harnesses I should use? The crutchfield site shows that I need or should use the following 3 pieces. Do I really need the gain controller below?

Nissan/Infiniti Receiver Wire Harness

http://www.crutchfield.com/p_120707550/Nissan-Infiniti-Receiver-Wire-Harness.html?tp=736

OEM diversity antenna cable

http://www.crutchfield.com/p_12040NI10/Nissan-Antenna-Adapter.html

Scosche OEM Amplifier Adapter

http://www.crutchfield.com/p_142C4NN03/Nissan-Infiniti-Factory-Integration-Adapter.html?tp=3486&nvpair=AG_Size%7cFFDouble%40DIN

 

Thanks in advance for your time.

Seth

[Towncivilian]

If upgrading to aftermarket speakers, either run your own speaker wiring or bypass the amps entirely. The FSM has wiring diagrams and schematics to make this very easy. I bypassed the amps in my Pathfinder. I think it's the better way to go, since if you use that amplifier adapter your output will be quieter I believe. I still have my Scosche adapter if you choose to go this route, I'd let it go for the cost of shipping.

[Timmons]

You should pull all that crap out of the vehicle and start over. It will sound better. Double din Pioneer with Flat Screen multi media and GPS. Put in some Focals or JBL's. Use good wire and amplifiers. I will post what i did to mine this weekend when it's half way done finally. Still need to install the JL audio 12" sub in right quarter panel. They make subs that are thin now and still pound out the bass.

 

That bose system was crap when I bought mine brand new from the dealer. LOL.

[Slartibartfast]

I've got an aftermarket head with the stock amps, and new speakers in the doors, and I haven't had any issues. If I turned it all the way up, I probably could damage something, but I'd be deaf for life long before then. Unless it's really pounding, you're probably good. (I blew out a factory speaker with the stock deck, but only because the foam was all dried up and crumbly.)

 

You're right, the stock head unit is quite weak. I hooked mine up to a computer power supply (12v) and a door speaker from a Ford. It's very quiet, even turned all the way up. I don't think it was intended to power speakers on its own. Not entirely sure what Nissan's thinking was there.

 

I've been considering a ghetto bypass (just connect the input and output wires that would've gone into the amp) rather than running all new wire. Should be pretty easy. Not as good of course, but as I'm not swapping any more speakers (unless they blow), it should be an improvement at least.

 

As for your links:

 

#1 Looks good to me.

#2 Depends on if your aftermarket head has the plug for the stock antenna. I'm fairly sure mine did.

#3 Only if you're keeping the stock amps.

 

Also keep in mind my experience is with WD21, R50 may well differ.

Edited September 30, 2011 by Slartibartfast

[adamzan]

The idea behind the non powered deck was to use the amps for power...

[Tungsten]

If upgrading to aftermarket speakers, either run your own speaker wiring or bypass the amps entirely. The FSM has wiring diagrams and schematics to make this very easy. I bypassed the amps in my Pathfinder. I think it's the better way to go, since if you use that amplifier adapter your output will be quieter I believe. I still have my Scosche adapter if you choose to go this route, I'd let it go for the cost of shipping.

 

x2

 

Run 14 gauge wiring to all the speakers and bypass factory wiring completely.

[devonianwalk]

I ran new wiring to all of my speakers from my after market stereo. Sounds great to me!

[XPLORx4]

OK, it sounds to me like you want to replace the head unit, but plan to keep the stock speakers and stock Bose amps. That will work, but you need to use the Scosche adapter. The factory HU outputs low-level signals to the amps (one attached to each front door speaker, and a 2-channel amp behind the left rear cargo panel for the rear speakers). A new HU will output high-level signals, which need to be attenuated down to the low-level signals. The Scosche adapter does this.

 

You cannot bypass the Bose amps and use the stock speakers with an new HU because the stock speakers have an impedance of only 1 ohm, instead of the 4-ohm load that aftermarket units need. So, if you plan to bypass the Bose amps, you must also replace the speakers.

 

When I replaced my audio system, I didn't reuse anything except the factory wiring. I installed a Pioneer AVIC head unit, an Alpine 4-channel amp, 4 new door speakers, and a 10" subwoofer. Originally, I didn't have the sub, but the sound from only the door speakers was still unsatisfying because it lacked deep bass. The front speakers and sub are powered by the amp, and the rear speakers are powered by the HU.

 

In short, if you want to keep your Bose amps and speakers, just get a new HU and the Scosche adapter. If you want to replace your speakers, just get a new HU, skip the Scosche adapter, and yank out the Bose amps.

Edited September 30, 2011 by XPLORx4

[Tungsten]

OK, it sounds to me like you want to replace the head unit, but plan to keep the stock speakers and stock Bose amps. That will work, but you need to use the Scosche adapter. The factory HU outputs low-level signals to the amps (one attached to each front door speaker, and a 2-channel amp behind the left rear cargo panel for the rear speakers). A new HU will output high-level signals, which need to be attenuated down to the low-level signals. The Scosche adapter does this.

 

You cannot bypass the Bose amps and use the stock speakers with an new HU because the stock speakers have an impedance of only 1 ohm, instead of the 4-ohm load that aftermarket units need. So, if you plan to bypass the Bose amps, you must also replace the speakers.

 

When I replaced my audio system, I didn't reuse anything except the factory wiring. I installed a Pioneer AVIC head unit, an Alpine 4-channel amp, 4 new door speakers, and a 10" subwoofer. Originally, I didn't have the sub, but the sound from only the door speakers was still unsatisfying because it lacked deep bass. The front speakers and sub are powered by the amp, and the rear speakers are powered by the HU.

 

In short, if you want to keep your Bose amps and speakers, just get a new HU and the Scosche adapter. If you want to replace your speakers, just get a new HU, skip the Scosche adapter, and yank out the Bose amps.

 

That depends on how you hook it up. Most head units have both a line level output and a high level signal output. I think the adapter uses the line level output of the aftermarket deck rather than attenuate signals but I don't know for sure.

 

To whoever wants to keep the factory speakers: I recommend getting some better speakers if you want better sound because that BOSE stuff is junk.

Edited September 30, 2011 by Tungsten

[tecciball]

Thanks all for the quick feedback.

 

So I dont want to dump a bunch of money on this. And even less time. I think I will get the best upgrade with the least cost by replacing the HU and front speakers. Since the fronts have individual amps in each door, which will be removed, they can get power from the HU. For the rears, I will use the Scosche adapter. Does anyone think I will have a problem using only half of the Scosche adapter? Will there be a power and remote wire to each front door for the amps? Do I need to do anything with those to avoid noise or electrical issues?

[Towncivilian]

You cannot bypass the Bose amps and use the stock speakers with an new HU because the stock speakers have an impedance of only 1 ohm, instead of the 4-ohm load that aftermarket units need. So, if you plan to bypass the Bose amps, you must also replace the speakers.

They are 2 ohms, not 1 ohm.

 

For the rears, you can just bypass the stock wiring by removing the rear amp, cutting a few wires on its wiring harness and soldering them together. I can give you a list of which wires to solder together later if you wish to do this.

[MrT]

Just an FYI: Using a speaker with a higher impedance rating is fine, you'll just get less "volume" from them. Going lower can blow your amp though.

You don't need the schosche adapter either if your new HU has line outs (RCA plugs) and you can solder or figure out a crimp connector. All it does is convert a speaker level signal to line level.

 

Run 14 gauge wiring to all the speakers and bypass factory wiring completely.

 

This is complete overkill unless you have one crazy system. You'll need 18 AWG max. And contrary to what anyone who is "in the know" will tell you, lamp cord works just fine; It's just ugly, but usually cheaper.

 

And the stock Bose system sucks. I will agree with that.

Edited October 5, 2011 by MrT