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New stereo system = new wiring?
Posted: Sun Nov 28, 2021 12:55 am
by nlmajors
2003 Cobalt 240. Current setup is a Sony HU, six 6.5" Sony speakers. one Rockford Fosgate M 500, 5 channel amp, and two 10" Rockford Fosgate subs.
Here's what I want to do.
Change out HU to a Rockford Fosgate 2.7" Digital media Receiver - PMX-5CAN with two wired remotes (one at helm, and one in transom)
Add a 4 channel Rockford Fosgate amp (M2-300)
Replace the Sony speakers with JL M3's with LED lighting
Add two 8'8" JL M6's. I'm having a custom enclosure built in the center storage (where the old 12v air compressor used to be) to face out to back behind the boat.
The existing Rockford Fosgate M500 amp will run 4 of the interior JL's (bow and center) and the subs.
The new Rockford Fosgate M2-300 will run the rear JL's and the two 8" JL's placed in the center storage.
Questions: (2) Any thing wrong with this setup? (2) will wiring in a 16 year old boat handle this or do I need to look at replacing the wiring?
Re: New stereo system = new wiring?
Posted: Mon Nov 29, 2021 6:25 am
by VTENGR
at the very least you're going to have to run wires to your existing 6 Sony speaker locations for the RGB controls for the LEDs on your new M3 speakers. My opinion, if you're doing that may as well run the speaker wire too and get new, upgraded speaker wire in there. It will be easy to run since the wires are already there.
Re: New stereo system = new wiring?
Posted: Sun Dec 05, 2021 9:11 pm
by NautiGirl
nlmajors wrote: Sun Nov 28, 2021 12:55 am
2003 Cobalt 240. Current setup is a Sony HU, six 6.5" Sony speakers. one Rockford Fosgate M 500, 5 channel amp, and two 10" Rockford Fosgate subs.
Here's what I want to do.
Change out HU to a Rockford Fosgate 2.7" Digital media Receiver - PMX-5CAN with two wired remotes (one at helm, and one in transom)
Add a 4 channel Rockford Fosgate amp (M2-300)
Replace the Sony speakers with JL M3's with LED lighting
Add two 8'8" JL M6's. I'm having a custom enclosure built in the center storage (where the old 12v air compressor used to be) to face out to back behind the boat.
The existing Rockford Fosgate M500 amp will run 4 of the interior JL's (bow and center) and the subs.
The new Rockford Fosgate M2-300 will run the rear JL's and the two 8" JL's placed in the center storage.
Questions: (2) Any thing wrong with this setup? (2) will wiring in a 16 year old boat handle this or do I need to look at replacing the wiring?
Coming out of retirement for this one, because I loce pointing out how bad Cobalt stereo setups were in the mid 2000's. I did a complete stereo refresh in our 07 222 a few years back, I did a big writeup on what we did, others have done similar. Lot of good info on setups, do a search and you should find some posts. On the surface that build looks a lot like what I ended up with.
The power and ground wire Cobalt used in our boat, and I assume all boats around that year, is stupid undersized even for the factory stereo. Our boat came from the factory with dual Sony 400watt amps and Cobalt ran 8ga wire. I was honestly shocked when I pulled it all out, here is a pic. I wouldnt try to run either of those JL Amps on this. IIRC JL Specs 6ga as a min I would run 4.
Also included a pic of our nicely terminated and heat-shrunk 4ga I replaced it with just to show off. Running power wire really wasnt too hard, really no excuse not to do it.
Good luck /w the setup.
power Wire.jpg
pwerwire2.jpg
Re: New stereo system = new wiring?
Posted: Sun Dec 05, 2021 11:37 pm
by nlmajors
Good info. Thanks. I'd hate to put the money into this upgrade and it not be able to perform at it's full potential.
Re: New stereo system = new wiring?
Posted: Mon Dec 06, 2021 9:13 am
by jhnmdahl
Yeah, I "second" what the others have said - it's not as hard as it looks to run new wires, and heavier gauge speaker wire and power supply wires will make a big difference in sound/performance for relatively little cost.
I posted a thread summer of 2020 that had a handful of pictures of my stereo upgrade too - check out Nauti's and a few others for ideas and you should be in good shape. Also, creativeaudio.net gives a discount to forum members, and they're great about making sure you do it right as well as good with pricing.
John
Re: New stereo system = new wiring?
Posted: Mon Dec 06, 2021 6:12 pm
by Big Block Power
NautiGirl wrote: Sun Dec 05, 2021 9:11 pm
nlmajors wrote: Sun Nov 28, 2021 12:55 am
2003 Cobalt 240. Current setup is a Sony HU, six 6.5" Sony speakers. one Rockford Fosgate M 500, 5 channel amp, and two 10" Rockford Fosgate subs.
Here's what I want to do.
Change out HU to a Rockford Fosgate 2.7" Digital media Receiver - PMX-5CAN with two wired remotes (one at helm, and one in transom)
Add a 4 channel Rockford Fosgate amp (M2-300)
Replace the Sony speakers with JL M3's with LED lighting
Add two 8'8" JL M6's. I'm having a custom enclosure built in the center storage (where the old 12v air compressor used to be) to face out to back behind the boat.
The existing Rockford Fosgate M500 amp will run 4 of the interior JL's (bow and center) and the subs.
The new Rockford Fosgate M2-300 will run the rear JL's and the two 8" JL's placed in the center storage.
Questions: (2) Any thing wrong with this setup? (2) will wiring in a 16 year old boat handle this or do I need to look at replacing the wiring?
Coming out of retirement for this one, because I loce pointing out how bad Cobalt stereo setups were in the mid 2000's. I did a complete stereo refresh in our 07 222 a few years back, I did a big writeup on what we did, others have done similar. Lot of good info on setups, do a search and you should find some posts. On the surface that build looks a lot like what I ended up with.
The power and ground wire Cobalt used in our boat, and I assume all boats around that year, is stupid undersized even for the factory stereo. Our boat came from the factory with dual Sony 400watt amps and Cobalt ran 8ga wire. I was honestly shocked when I pulled it all out, here is a pic. I wouldnt try to run either of those JL Amps on this. IIRC JL Specs 6ga as a min I would run 4.
Also included a pic of our nicely terminated and heat-shrunk 4ga I replaced it with just to show off. Running power wire really wasnt too hard, really no excuse not to do it.
Good luck /w the setup.
power Wire.jpg
pwerwire2.jpg
By the way Jeef painted his /her finger nails just for that job!




Re: New stereo system = new wiring?
Posted: Mon Dec 06, 2021 6:40 pm
by NautiGirl
Big Block Power wrote: Mon Dec 06, 2021 6:12 pm
NautiGirl wrote: Sun Dec 05, 2021 9:11 pm
nlmajors wrote: Sun Nov 28, 2021 12:55 am
2003 Cobalt 240. Current setup is a Sony HU, six 6.5" Sony speakers. one Rockford Fosgate M 500, 5 channel amp, and two 10" Rockford Fosgate subs.
Here's what I want to do.
Change out HU to a Rockford Fosgate 2.7" Digital media Receiver - PMX-5CAN with two wired remotes (one at helm, and one in transom)
Add a 4 channel Rockford Fosgate amp (M2-300)
Replace the Sony speakers with JL M3's with LED lighting
Add two 8'8" JL M6's. I'm having a custom enclosure built in the center storage (where the old 12v air compressor used to be) to face out to back behind the boat.
The existing Rockford Fosgate M500 amp will run 4 of the interior JL's (bow and center) and the subs.
The new Rockford Fosgate M2-300 will run the rear JL's and the two 8" JL's placed in the center storage.
Questions: (2) Any thing wrong with this setup? (2) will wiring in a 16 year old boat handle this or do I need to look at replacing the wiring?
Coming out of retirement for this one, because I loce pointing out how bad Cobalt stereo setups were in the mid 2000's. I did a complete stereo refresh in our 07 222 a few years back, I did a big writeup on what we did, others have done similar. Lot of good info on setups, do a search and you should find some posts. On the surface that build looks a lot like what I ended up with.
The power and ground wire Cobalt used in our boat, and I assume all boats around that year, is stupid undersized even for the factory stereo. Our boat came from the factory with dual Sony 400watt amps and Cobalt ran 8ga wire. I was honestly shocked when I pulled it all out, here is a pic. I wouldnt try to run either of those JL Amps on this. IIRC JL Specs 6ga as a min I would run 4.
Also included a pic of our nicely terminated and heat-shrunk 4ga I replaced it with just to show off. Running power wire really wasnt too hard, really no excuse not to do it.
Good luck /w the setup.
power Wire.jpg
pwerwire2.jpg
By the way Jeef painted his /her finger nails just for that job!



Katie was in charge of heat shrink, I didn't have the patience to do it, she did an amazing job.
Re: New stereo system = new wiring?
Posted: Mon Dec 06, 2021 8:11 pm
by Big Block Power
NautiGirl wrote: Mon Dec 06, 2021 6:40 pm
Big Block Power wrote: Mon Dec 06, 2021 6:12 pm
NautiGirl wrote: Sun Dec 05, 2021 9:11 pm
Coming out of retirement for this one, because I loce pointing out how bad Cobalt stereo setups were in the mid 2000's. I did a complete stereo refresh in our 07 222 a few years back, I did a big writeup on what we did, others have done similar. Lot of good info on setups, do a search and you should find some posts. On the surface that build looks a lot like what I ended up with.
The power and ground wire Cobalt used in our boat, and I assume all boats around that year, is stupid undersized even for the factory stereo. Our boat came from the factory with dual Sony 400watt amps and Cobalt ran 8ga wire. I was honestly shocked when I pulled it all out, here is a pic. I wouldnt try to run either of those JL Amps on this. IIRC JL Specs 6ga as a min I would run 4.
Also included a pic of our nicely terminated and heat-shrunk 4ga I replaced it with just to show off. Running power wire really wasnt too hard, really no excuse not to do it.
Good luck /w the setup.
power Wire.jpg
pwerwire2.jpg
By the way Jeef painted his /her finger nails just for that job!



Katie was in charge of heat shrink, I didn't have the patience to do it, she did an amazing job.
Really that's all the credit you are giving Katie? Come on tell the truth she did the install!
Re: New stereo system = new wiring?
Posted: Tue Dec 07, 2021 5:31 am
by Krob1114
NautiGirl wrote: Sun Dec 05, 2021 9:11 pm
nlmajors wrote: Sun Nov 28, 2021 12:55 am
2003 Cobalt 240. Current setup is a Sony HU, six 6.5" Sony speakers. one Rockford Fosgate M 500, 5 channel amp, and two 10" Rockford Fosgate subs.
Here's what I want to do.
Change out HU to a Rockford Fosgate 2.7" Digital media Receiver - PMX-5CAN with two wired remotes (one at helm, and one in transom)
Add a 4 channel Rockford Fosgate amp (M2-300)
Replace the Sony speakers with JL M3's with LED lighting
Add two 8'8" JL M6's. I'm having a custom enclosure built in the center storage (where the old 12v air compressor used to be) to face out to back behind the boat.
The existing Rockford Fosgate M500 amp will run 4 of the interior JL's (bow and center) and the subs.
The new Rockford Fosgate M2-300 will run the rear JL's and the two 8" JL's placed in the center storage.
Questions: (2) Any thing wrong with this setup? (2) will wiring in a 16 year old boat handle this or do I need to look at replacing the wiring?
Coming out of retirement for this one, because I loce pointing out how bad Cobalt stereo setups were in the mid 2000's. I did a complete stereo refresh in our 07 222 a few years back, I did a big writeup on what we did, others have done similar. Lot of good info on setups, do a search and you should find some posts. On the surface that build looks a lot like what I ended up with.
The power and ground wire Cobalt used in our boat, and I assume all boats around that year, is stupid undersized even for the factory stereo. Our boat came from the factory with dual Sony 400watt amps and Cobalt ran 8ga wire. I was honestly shocked when I pulled it all out, here is a pic. I wouldnt try to run either of those JL Amps on this. IIRC JL Specs 6ga as a min I would run 4.
Also included a pic of our nicely terminated and heat-shrunk 4ga I replaced it with just to show off. Running power wire really wasnt too hard, really no excuse not to do it.
Good luck /w the setup.
power Wire.jpg
pwerwire2.jpg
Damn...I missed the retirement party. Glad to have you back.
Re: New stereo system = new wiring?
Posted: Tue Feb 01, 2022 9:58 pm
by jsmith262
Sorry to bring up an old thread, but out of curiosity, how much power and ground wire did you all use when upgrading the factory wiring? I keep my boat at the marina 3 hours from my house so I can't run to check before I order. Mine is a 2011 262 so amps are in the compartment in front of the helm.
TIA.