2008 Accord Coupe - factory upgrade
Upgrade build log – 2008 Honda Accord Coupe (EXL)
I am in the very early stages of an upgrade to my OEM system after recently joining the forums. Initially I needed to do a lot of research as although I’m not new to high-end car audio (I was an installer in the past) things have changed dramatically since I installed in the early 1990’s.
Here are the goals I have in mind:
• Low cost
• Stealth (in cabin)
• Utilize factory head unit
• Designed for sound quality
• Utilize factory charging system
I listen to a mix of music depending on my mood but typically fall back to something bass heavy. When I’m in the mood for Jazz I need a system that can reproduce vocals and saxophones without sounding harsh.
Regarding the factory HU, here’s my thought process: Obviously, its stealth as there wouldn’t be an aftermarket head unit and cars have changed – where we used to put a DIN (or double DIN) is most cars, factory head units have changed substantially making this difficult. Additionally, I have the upgraded audio system with external amp and in the Accord forums there’s an individual who competes using the stock HU as it provides a 4V balanced output that can be adapted to RCA. Using the stock HU would allow me the additional capability of balance, fader and subwoofer output as I have 5 channels coming out of the HU.
Here’s my plan: Factory HU converted to 5 channel balanced outputs. Mono block amp driving a single 12” subwoofer and 4 channel amp driving 6.5” components in the front (stereo) and rear in tri-mode mono. For the rear, I might use a coaxial 6.5” or possible a quality 6.5” mid bass driver than can make it to 5 KHz + for fill. I’m contemplating keeping an 8” OA solution and using it as a woofer from 50 Hz up. If I use a 8” woofer, I don’t know if I’ll need to enclose it but I haven’t done that in the past and without driving a few thousand watts into a 12” sub it shouldn’t be impacted. I spent time in August sealing off the rear deck with sound deadening to get rid of rattles and dramatically enhanced the sound of the factory sub – output decreased slightly but low end is crazy shaking the entire car and impacting the mirrors more than I’ve seen with a factory system. Many owners complain about this sub (Pioneer?) but Honda did a terrible job isolating the front from the back on the rear deck and the difference in sealing it is remarkable.
Along with the upgrades I need to get rid of some “rattles” and “buzzes” and will be adding more sound deadening to the rear deck as well as going through the doors. Not sure whether I’ll trim out the trunk (don’t planning on competing) or just keeping the install clean. I also plan on building (or buying) a standard enclosure for the sub (haven’t decided on sealed or ported) instead of removing the spare and using that space.
My plan is to use Zapco amps and still deciding on components. I have a friend that will sell me a new in box Alpine Type R 12” sub (old gray style) that he never used. I’m intrigued but it’s dual 2 ohm voice coils and while Zapco amps handle 1 ohm they prefer 2 ohm for efficiency. This isn’t as big of a deal on a sub so I might do it anyway. I lean towards a Class D mono block, i.e. ST-500XM II, producing 500 watts at 1 ohm and a Class AB 4 channel, possibly ST-4XSQ @ 70 watts x 4.
If I’m able to start soon, I’ll focus on the mono block, sub and sound deadening the front doors. I live in IA so installs aren’t popular in the winter and my garage is old (i.e. not heated) but it’s still comfortable outside right now. I need to tread lightly on the finances so my wife doesn’t freak out and currently have some unused electronics for sale to pay for stage 1. I also have some OCD and love car audio – it’s an addiction that I need to keep from getting out of control.
Was a professional installer in the early 90's - things have certainly changed!
Current: Honda premium HU, Zapco ST-X5II running stock components and Alpine Type R (sealed)
Planning on adding AudioControl Three.2 and using balanced differential keeping stock HU for control/EQ
Researching 6.5" components to replace stock in doors