As I am planning to upgrade from my dead CDR23 CD player to a Pioneer or Clarion Nav unit with the eBay kit, a friend of mine (who will most likely be working with me on this upgrade) brought up a question...

Anyone knows the ohm rating of the factory Bose speakers?

I am not very technical compared to my friend as he just loves doing this as a hobby, he mentioned that if the factory speakers have any special ohm rating...like 2, 4 ohms? If its mostly standard speakers, probably easier to bypass the factor amp entirely. Either use the built-in head unit amp or external 4 channel amp.

 

This is a great write up from TINS...

After a few months and numerous discussions with various "experts" Here is what I've discovered:

- After MY 2002 1/2 Porsche began using MOST bus system (fiber optic).
- Head unit replacement requires replacement of the amp (one 5 channel amp runs the OEM system, it's located next to the spare)
- The Bose speakers are 2 ohm, the Bose subs are also 2 ohm, but are wired in parallel and therefore in original configuration run at 1 ohm.
- There are very few amps that run stable at 1 ohm.
- You can re-wire the Bose subs in series and they will run as 4 ohm
- Your choice is to replace everything (head unit, amp, and speakers) and have full flexibility in the equipment and sound quality you want...
or
- Re-wire the sub woofers in series and just replace the head unit and amp. Sub woofer enclosure is easily removed by carefully pulling off the trim ring surrounding the ports from the top, exposing torx screws. When these are removed the whole enclosure slides forward.
- I ordered a pre-MOST system Porsche amp with the idea of a plug and play amp solution, however the connectors for these amps are not compatible and although you could retro fit a 2002 connector the amp isn't that good and is +/-$700.

My solution:

I run a B&B exhaust, good performance and sound, but loud, so I was not striving for great audio sound (I wouldn't be able to appreciate it over the exhaust note). I elected to leave in the Bose speakers, re-wire the subs to series and replace the amp and head unit. I found the Kenwood DNX 8120 http://www.kenwoodusa.com/Car_Entert...gation/DNX8120
head unit as currently best in class, and the Alpine PDX-5 (5 channel) http://www.alpine-usa.com/US-en/prod...hp?model=PDX-5 will run speakers (2 ohms) and subs (once they are re-wired) to 4 ohm. I chose the Alpine because it fits well in the location of the Porsche CD changer. There are better quality amps available but they are significantly larger and will eat up some of the precious cargo space.

This is a simple install because most of the necessary wiring (speaker and power) is already in place. The installer only has to feed line out cables from the new head unit through the firewall to the amp.

The GPS antenna fits nicely under the plastic bridge behind the alarm LED in the center of your dash. The Sat radio antenna (if you choose to add it) fits under the plastic cowl in front of the windshield wipers. This cowl has allowed for a good signal. The mic for the bluetooth phone application can be drilled into over head cowl. I think it fits best vertically centered just in back of the sunroof motor (there are 2 screws under the infrared security readers that hold the cowl in place. Remove these to see the location I'm describing). An alternate location and easier install (although I believe poorer performance because it is adjacent to the vent and will pick up the sound of heat or A/C air movement) is in the plug just to the right of the ignition. This plug pulls straight out.

The cable for I-Pod integration runs into the glove-box

I also found a wireless rear view camera that integrates nicely (not necessary, but this is supposed to be fun right?). Super easy to install if you provide it to you installer while he is installing the head unit. http://boyovta.com/products/vtx420.html no wires front rear bumper to front of the car. Power is connected up through the license plate lamps, into the engine bay, and over to the reverse lamps.

In my opinion regardless of the skills of an installer, the less dis-assembly the better. The Kenwood NAV, phone and Ipod interface, and GUI are excellent. The sound quality with the OEM speakers and the Alpine amp is clearly superior over stock and satisfactory for me given my application. If you are a true audiophile you will want to replace the speakers and subs.

If you want to upgrade everything this is the best solution I've found. Retain the OEM sub enclosure the Focal 13 KS subs http://www.focal-america.com/ are 5" subs fit perfectly. You can experiment with blocking or keeping open the ports (in the end sound is a preference). Sound connoisseurs will tell you that the enclosure is sub par due to it's plastic construction, I'm not convinced that's true. The Focal 130 KP are good speaker replacements and will fit with the OEM grills.

For better quality amps I would use the Genesis Profile Series. They are low profile and light weight. http://www.genesis-ice.com/. The 5 channel will fit in the place of the OEM CDC and extend over the black hump located at the center of the trunk. This black cover will need to be re-made 1.5" lower for the amp to fit under the hood. A qualified install shop can do this easily, but at some expense.


Hopefully this will save you the time, mis-direction and, and expense I have into what I thought was going to be a simple head unit exchange project.
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Absolutely, thanks a lot for your message!!

 

I have been reading so many threads from various forums as I look for ways to improve or replace my '03 Boxster 986's CDR023 Bose system, and this is probably the MOST informative post I have read. Thank you so much!

Just wish I knew where / what TINS... is.