Audio Upgrade Complete
After months of stop/starting, I have finally completed my audio upgrade. Essentially I have removed the requirement for the head unit and go straight from my Car PC to the Amp, then speakers. The audio upgrade components consist of:
Creative USB Sound Blaster X-Fi 5.1 Surround External Soundcard
JBL GT5-A604 4ch Amp
JBL GT5-650C Front Components
JBL GT5-12 12" Subwoofer
The first requirement was to build the false boot wall to house the Subwoofer and hide the Amplifier/USB soundcard. For this I created a cardboard template of the boot area for the false wall and transferred to template onto 19mm MDF. Next I cut the 298mm hole for the 12" subwoofer and finally used 90mm wide batons to support the wall and help enclose it.
The predicted intrusion into the boot area...
A little black carpet added...
Trail fit...
The door panels were removed and the old front speakers/tweeters removed... (not many pics during this phase - sorry

)
The new JBL GT5-650C Front Components were fitted. I added decent speaker cable and routed them through the door connector (X3 and X4) - and what a job that was!...
With the front components fitted I was keen to get the subwoofer and amplifier fitted too...
The output from the Creative USB Sound Blaster X-Fi 5.1 Surround External Soundcard is set-up as 5.1, then the rear and centre speakers are removed from the set-up, front speakers identified as not full range so the bass can be re-directed to the subwoofer - Easy

. The soundcard subwoofer output is split in order to bridge two of the amp channels.
The last phase was attaching two brackets to ensure the already tight fitting false boot wall could fall over. Trust me, this is going nowhere now as the fit is incredibly tight!
The final product

...
And the Car PC on the other side...
All-in-all I'm happy with the outcome - and the sound is far better

.