Hi Guys,
I found a post on another forum somewhere about replacing a DSP head unit with a new one by hiding the original in the car and piggy-backing a new head unit in and thought I'd share my findings, as there are a few posts asking 'can I upgrade DSP' etc.
I can't take credit for the idea, the stuff I read (trying to find the link now) gave me the idea and I just added to it.
I have the full carver system, which has 2x analogue inputs from the back of the head unit. To gloss over all the middle bits, by connecting the upgraded head units front RCA connections to the 2 inputs and leaving the old head unit still wired up with everything else, you can trick the amp to thinking the audio signal is coming from the original head unit.
Here is some more detail:
DISCLAIMER - I'm not an auto electrician, feel free to try this but don't blame me if your system goes up in smoke!
Also, if anyone can spot any issues with what I have done, please feel to point them out to me, i won't be offended!
Step 1: Remove vents and existing head unit.
Step 2: Unwrap the cloth wrap stuff from the stereo wires.
Step 3: Decide where the head unit will go, it needs to be accessible to start with, I intend to mount mine behind the passenger seat for adjustment and then into the boot in the future.
Step 4. Cut off the existing connector from the loom at a sensible point and extend all the wires to the head units new location. You need to extend all the wires apart from the 4 at the right hand side of the connector, closest 4 on this photo (blue/red, yellow/red & 2x browns). It's easier to use connector blocks than bullet connectors for this as you will need to add other cables later.

Step 5: Clip the connector back into the old head unit and stuff under seat or wherever, as you will need to get to it soon. The head unit is now fully connected to the car apart from the signals to the Carver amp, thats what the 4 wires we didn't extend are for.
Step 6: Attach fascia panels, stereo cage etc for the new head unit.
Step 7: Connect new head units power, dimmer, acc, remote, etc to the connector blocks following the head units wiring instructions. Do not try to connect any speaker cables.
Step 8: Get a RCA connector and cut off one end. This then needs to be connected (using connector blocks or bullets) to the 4 wires we didn't extend. Browns to the negative of the RCA's and the colours to the positive.
Step 9: This may vary depending on your head unit, but mine has front and sub RCA out, some have front and rear, some have all 3. I connected the red and white RCA to the front RCA out. This now means a low voltage analogue signal is being passed to the amp.
Step 10: Re-build your dash and get your new head unit secured.
At this point comes a lot of fiddling around with sound settings and it will vary with each individual head unit and taste in sound, so I'll leave the 'make it sound good step to each of you. You will want to set the head unit to a suitable level and forget about it. All the changes can then be made on the new head unit. You'r effectively using the old head unit as a equaliser.
I personally had the Bass and Trebble up to one off max and the balance and fade set to central.
When you switch the car on the old head unit wakes the amp up using the i-bus which was extended in step 4, and the system thinks all is good, it doesn't understand that the audio is coming from another source.
Niggles / Issues.
The volume level on the old head unit is high as the RCA output is quiet. This might be my new head unit, I can't find what voltage the carver amp needs. It may be possible use the new head unit speaker connections, but i need to check voltages before blowing the amp up. The high volume on the head unit means that as the new head unit is turned up it can crackle a little. But this is only noticeable when your ears are bleeding.
If you turn off the new head unit, the old one is still on (in the boot or wherever) and it does have a slight hiss on the speakers.
But it works....
If anyone out there knows more about electrics than me (and thats probably everyone!) feel free to comment / critique / add 2p's worth. I'm interested to get this right and think the discussion might help others!
Wattsie
I found a post on another forum somewhere about replacing a DSP head unit with a new one by hiding the original in the car and piggy-backing a new head unit in and thought I'd share my findings, as there are a few posts asking 'can I upgrade DSP' etc.
I can't take credit for the idea, the stuff I read (trying to find the link now) gave me the idea and I just added to it.
I have the full carver system, which has 2x analogue inputs from the back of the head unit. To gloss over all the middle bits, by connecting the upgraded head units front RCA connections to the 2 inputs and leaving the old head unit still wired up with everything else, you can trick the amp to thinking the audio signal is coming from the original head unit.
Here is some more detail:
DISCLAIMER - I'm not an auto electrician, feel free to try this but don't blame me if your system goes up in smoke!
Also, if anyone can spot any issues with what I have done, please feel to point them out to me, i won't be offended!
Step 1: Remove vents and existing head unit.
Step 2: Unwrap the cloth wrap stuff from the stereo wires.
Step 3: Decide where the head unit will go, it needs to be accessible to start with, I intend to mount mine behind the passenger seat for adjustment and then into the boot in the future.
Step 4. Cut off the existing connector from the loom at a sensible point and extend all the wires to the head units new location. You need to extend all the wires apart from the 4 at the right hand side of the connector, closest 4 on this photo (blue/red, yellow/red & 2x browns). It's easier to use connector blocks than bullet connectors for this as you will need to add other cables later.

Step 5: Clip the connector back into the old head unit and stuff under seat or wherever, as you will need to get to it soon. The head unit is now fully connected to the car apart from the signals to the Carver amp, thats what the 4 wires we didn't extend are for.
Step 6: Attach fascia panels, stereo cage etc for the new head unit.
Step 7: Connect new head units power, dimmer, acc, remote, etc to the connector blocks following the head units wiring instructions. Do not try to connect any speaker cables.
Step 8: Get a RCA connector and cut off one end. This then needs to be connected (using connector blocks or bullets) to the 4 wires we didn't extend. Browns to the negative of the RCA's and the colours to the positive.
Step 9: This may vary depending on your head unit, but mine has front and sub RCA out, some have front and rear, some have all 3. I connected the red and white RCA to the front RCA out. This now means a low voltage analogue signal is being passed to the amp.
Step 10: Re-build your dash and get your new head unit secured.
At this point comes a lot of fiddling around with sound settings and it will vary with each individual head unit and taste in sound, so I'll leave the 'make it sound good step to each of you. You will want to set the head unit to a suitable level and forget about it. All the changes can then be made on the new head unit. You'r effectively using the old head unit as a equaliser.
I personally had the Bass and Trebble up to one off max and the balance and fade set to central.
When you switch the car on the old head unit wakes the amp up using the i-bus which was extended in step 4, and the system thinks all is good, it doesn't understand that the audio is coming from another source.
Niggles / Issues.
The volume level on the old head unit is high as the RCA output is quiet. This might be my new head unit, I can't find what voltage the carver amp needs. It may be possible use the new head unit speaker connections, but i need to check voltages before blowing the amp up. The high volume on the head unit means that as the new head unit is turned up it can crackle a little. But this is only noticeable when your ears are bleeding.
If you turn off the new head unit, the old one is still on (in the boot or wherever) and it does have a slight hiss on the speakers.
But it works....
If anyone out there knows more about electrics than me (and thats probably everyone!) feel free to comment / critique / add 2p's worth. I'm interested to get this right and think the discussion might help others!
Wattsie
