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First, thanks for any assistance. I am in the process of upgrading to a double din in my C5. I have read many posts but am still a bit confused. Do all four speaker go through an amp and sound processor? I am replacing all speakers and am not sure if I can just tap into the existing wires or is it better to run all new wires? I think I read that the front have the built in amps and the rear speaker amp is in the head unit? I also thought I read the tapping into the existing wires will still force the sound through the processor which could impact the quality of my sound? I am not installing an expensive unit, not really interested in the volume, just having the features along with a slightly better sound. I am not adding an amp. So, tap into existing speaker wires, or run new direct to new HU? Thanks so much for any assitance!
First, thanks for any assistance. I am in the process of upgrading to a double din in my C5... ...I am replacing all speakers and am not sure if I can just tap into the existing wires or is it better to run all new wires?... ...I am not installing an expensive unit, not really interested in the volume, just having the features along with a slightly better sound. I am not adding an amp. So, tap into existing speaker wires, or run new direct to new HU? Thanks so much for any assistance!
What you want to do is perfectly feasible and the results are very satisfying. You will need to use an Axxess or PAC adapter. Use the factory wiring. Just click on this link to take you to a post that summarizes all the possible ways to upgrade. What you are looking for is explained in Option 4.
Originally Posted by lanier
...I have read many posts but am still a bit confused. Do all four speaker go through an amp and sound processor?... ...I think I read that the front have the built in amps and the rear speaker amp is in the head unit?... ...I also thought I read that tapping into the existing wires will still force the sound through the processor which could impact the quality of my sound?...
The C5 OEM Bose system's 4 main channels are composed of 2 front 3½" and 2 rear 5¼" (or 6½" if a coupe) twiddlers and all 4 of them are directly driven by the headunit's built-in 4-channel amp. In addition to that, each door has an 8" subwoofer directly driven by a dedicated amp that is mounted right besides it.
The C5 Bose system is based on a modified Delco headunit that uses pseudo-differential low level signals along with fully differential speaker level signals. The common signals are not standard and have a DC offset, so they cannot be grounded.
The way the Bose OEM system works, the audio signals from the head-unit are "detoured" through a signal processor, where a 2-way crossover filter is applied. The mids and highs receive additional "conditioning" and then are returned to the head-unit. At the same time, the signal processor adds up the low frequency information from the 4 channels and sends it to the 2 subwoofer amps in the doors.
The OEM head-unit has 4 female connectors in the back:
C1 / C2 (which is a single siamese connector) - power, ground, BCM data, front and rear speakers
C3 - power amp inputs
C4 - pre-amp outputs
are needed when replacing the headunit, in order to take care of all necessary interfacing and make the process plug-and-play.
Here is a diagram showing a replaced headunit while keeping the rest of the system intact (the diagram is the same for Axxess or PAC adapters). As you can see, the sound of the 4-main channels is not touched by the Bose DSP module. It is directly handled just by the new headunit.
You just need to power up the new head unit and run the speakers directly from it...
You say changing all speakers..with what?
Are you removing the bose woofers..and if so..with what..
Also..a head unit at best will only put out about 20 watts per channel which is not much..
yes, was planning on taking out the bose woofers-was going to replace with just some 6.5 speakers. maybe if i do that then just run speaker wires straight from HU directly to speakers. I have wired a few stereos in my day, but nothing even close to this mess.
yes, was planning on taking out the bose woofers-was going to replace with just some 6.5 speakers. maybe if i do that then just run speaker wires straight from HU directly to speakers. I have wired a few stereos in my day, but nothing even close to this mess.
Actually the Bose OEM system is very similar to a hometheater surround sound setup, with a receiver directly driving 4 small satellite speakers and complemented by 2 powered subwoofers.
You mentioned you just wanted to upgrade the headunit and the speakers, and that you didn't want any external amps and therefore, no aftermarket subwoofers either.
The best way to do that yielding the best results is to replace the headunit and the 4 main channel speakers (the 2 front 3½" and 2 rear 6½" - since you have a coupe) keeping the rest of the OEM infrastructure in place(and that includes not touching the 2 door-mounted 8" powered subwoofers).
Of course you can gut everything out, but if you are not going to install external amps and aftermarket subwoofers, it's not worth it. There would be no advantage and you would end up loosing the 2 OEM powered subwoofers.
That's why I suggested Option 4 in the link I gave you in my previous post:
Replace just the headunit, leaving the rest of the system intact, using either one of these adapters:
This is what i did but unfortunately did not get the jbls..i put in jl audio which are 4 ohm and not as sensitive..my problem is trying to balance the system..you have to adjust the gains with the adapter module in the axxess harness..i think i have one bad adjuster..channel
I have been wondering if replacing the woofers and 3.5 speakers with a 6.5 component and powering it directly from my HU which has an additional in line amp..would sound better..i dont like the sound of the bose woofers.
I downloaded a tuning app and pink noise generator to tune it
Cool stuff
Ldt us know how it comes out...you doing install?
This is what i did but unfortunately did not get the jbls..i put in jl audio which are 4 ohm and not as sensitive...
That makes all the difference in the world! Yes, these JBLs are the best replacement I've seen for this application, with half the impedance and higher sensitivity than what's commonly available (in addition to good quality, of course).
Originally Posted by mfi2000
...my problem is trying to balance the system..you have to adjust the gains with the adapter module in the axxess harness..i think i have one bad adjuster...
Sorry to hear that. Can you still exchange the Axxess under warranty?
Going to contact crutchfield..the right front speaker is being over driven..so its popping when it gets loud..the #1 channel is stuck..probably maxed and just spins now
What you want to do is perfectly feasible and the results are very satisfying. You will need to use an Axxess or PAC adapter. Use the factory wiring. Just click on this link to take you to a post that summarizes all the possible ways to upgrade. What you are looking for is explained in Option 4.
The C5 OEM Bose system's 4 main channels are composed of 2 front 3½" and 2 rear 5¼" (or 6½" if a coupe) twiddlers and all 4 of them are directly driven by the headunit's built-in 4-channel amp. In addition to that, each door has an 8" subwoofer directly driven by a dedicated amp that is mounted right besides it.
The C5 Bose system is based on a modified Delco headunit that uses pseudo-differential low level signals along with fully differential speaker level signals. The common signals are not standard and have a DC offset, so they cannot be grounded.
The way the Bose OEM system works, the audio signals from the head-unit are "detoured" through a signal processor, where a 2-way crossover filter is applied. The mids and highs receive additional "conditioning" and then are returned to the head-unit. At the same time, the signal processor adds up the low frequency information from the 4 channels and sends it to the 2 subwoofer amps in the doors.
The OEM head-unit has 4 female connectors in the back:
C1 / C2 (which is a single siamese connector) - power, ground, BCM data, front and rear speakers
C3 - power amp inputs
C4 - pre-amp outputs
This is why adapters like the Axxess XSVI-2004 and PAC ROEM-VET1 are needed when replacing the headunit, in order to take care of all necessary interfacing and make the process plug-and-play.
Here is a diagram showing a replaced headunit while keeping the rest of the system intact (the diagram is the same for Axxess or PAC adapters). As you can see, the sound of the 4-main channels is not touched by the Bose DSP module. It is directly handled just by the new headunit.
So if you just unplug the woofers and get rid of them and hook up a 6.5 component speakers they will run off the head unit...The adjuster module on the axxess does adjust the other speakers though and thats what I think mucks up the sound a bit..I guess you can't get that out of the picture.
So if you just unplug the woofers and get rid of them and hook up a 6.5 component speakers they will run off the head unit...
Not sure if this is what you mean , but if you unplug the OEM subwoofers and remove them and then install new speakers using the OEM subwoofer wiring, they would still be driven by the door-mounted amps, and there would be no point in using component speakers since only low frequencies from the Bose DSP will be reaching them.
Originally Posted by mfi2000
...The adjuster module on the axxess does adjust the other speakers though and thats what I think mucks up the sound a bit..I guess you can't get that out of the picture.
If you feel the Axxess is affecting or modifying the 4 main channels when you adjust its potentiometers, then something is not right. That, plus the defective potentiometer you mentioned above, might explain why you perceive the resulting overall sound as mucked up.
I would suggest replacing the Axxess unit and readjusting relative levels.
Neither the Axxess or PAC interfaces should interfere with the 4 main channels. This interface just taps into each of the 4 main channels speaker outputs. It is not inserted in-line to provide a modified speaker output, it only taps the speaker outputs to derive line level signals to feed the Bose DSP module, while keeping the speaker level circuits isolated from this "branching" as can be seen in the diagram. The adjusting potentiometers should only change the relative level of the 2 door-mounted 8" subwoofers.
Originally Posted by GCG
...Here is a diagram showing a replaced headunit while keeping the rest of the system intact (the diagram is the same for Axxess or PAC adapters). As you can see, the sound of the 4-main channels is not touched by the Bose DSP module (nor modified or affected by the adapting interface). It is directly handled just by the new headunit.
I first set the pots all the way down and had no sound..then starting raising 1 channel and measured with my dsp meter..then went through all channels..it definately affects all speakers..the module has 4 channels..
When i put the new one in ill pull the door panels and see whats what..but im tired of doing this
And no..i would hook up the component speakers to the line feeding the 3.5's using the supplied crossover for now..but at this point..wiring in an amp and ditching all this bs is better..but would double the cost..but ill do this any way..just wondering if i can buy the focals..which are a grand..and just hook them up where the fronts are using an adapter plate. I have 45 watts available which should drive them
Unplug c4 and you ca see what your system will sound like without subs. Funny when you do this the front and back speakers will all have the same sound level. Then plug it back in and now the rears are gone. I think it is just due to the sub being over powered.
First, thanks for any assistance. I am in the process of upgrading to a double din in my C5. I have read many posts but am still a bit confused. Do all four speaker go through an amp and sound processor? I am replacing all speakers and am not sure if I can just tap into the existing wires or is it better to run all new wires? I think I read that the front have the built in amps and the rear speaker amp is in the head unit? I also thought I read the tapping into the existing wires will still force the sound through the processor which could impact the quality of my sound? I am not installing an expensive unit, not really interested in the volume, just having the features along with a slightly better sound. I am not adding an amp. So, tap into existing speaker wires, or run new direct to new HU? Thanks so much for any assitance!
If you do this with new wire hook directly to HU please post up what it sounds like. I was thinking of do this myself and maybe add a power sub (slim line) later. My main reason is I think either the speakers or the bose amp is going out. Certain songs like Pantera cemetery gates, Almost all metallica cause weird distortion went it hit the lows.
Wanted to thank everyone for all the great advise with assisting me with this project (especially to GSG)! Goal was to have better sound, the features of a double din and a backup camera. I kept the stock woofers and put JBL’s in for tweeters as suggested. I had some new Pioneer 3 ways lying around from an old project and I placed those in the back. They do sound way better, but still debating if it would be worth it to put JBL’s in the back since I did not install an amp. I tried saving the old bezel and modifying it, but it was looking like crap so I decided to get the conversion bezel-good choice, looks way better. Result was exactly what I was hoping for, much better sound, really all the volume and bass I need for my listening along with a back up camera and Bluetooth. Below are my final costs in case anyone is interested:
-Boss Audio Systems BVB9358RC with rear view -$74 (Prime Day)
-JBL GX302 150W 3.5in 2-Way GX Series-$49
-Axxess XSVI-2004 Amplifier Interface Harness-$60
-Scosche Wire Harness FM Antenna Adapter-$6
-Metra DP-3021B Black Double DIN-$174
-12V Lighter Socket Dual 2.1A USB Port Charger LED-$7
-Rear speaker harness/adapter $7
Total cost-$377
Upgrading Head Unit-run new speaker wires ?
Axxess XSVI-2004 
Yes, these JBLs are the best replacement I've seen for this application, with half the impedance and higher sensitivity than what's commonly available (in addition to good quality, of course).
, but if you unplug the OEM subwoofers and remove them and then install new speakers using the OEM subwoofer wiring, they would still be driven by the door-mounted amps, and there would be no point in using component speakers since only low frequencies from the Bose DSP will be reaching them.
