Swapping out Most based audio

[Deetoo]

Hi - My car is very late '03 facelift S with the Bose upgrade inc subwoofer behind seats. I want to get rid of the Head unit (think it's a CDR23) and replace it with something Ipod friendly and built in Bluetooth. I realise the Most Bus will cause problems but am I right in thinking that if I take out the power amp as well as the head unit the speakers are wired normally?

Has anybody any experience of this sort of mod?

[AndyW]

Bump....I am looking to do something similar on an '07 Bose setup.

I stopped by an audio shop, and they claim, everything needs to come out, including sub and replaced. Total cost for Pioneer AVIC-Z2 install + amp, speakers and 10" sub is a little over 6K (Yikes!). I was hoping to do something a little less extreme, like replace the head unit and amp....

Anyone know if this is feasible? The 6K sounds like they added the "he drives a porsche" tax.

-- Andy

[Loren]

The problem is that you a a MOST (fiber optic) linked sound system in your car. To replace it requires adding wiring for a traditional sound system.

[graylens]

I'm considering doing the same to my 2003 Boxster S, but I just have the "Hi Fi" system -- is it true only the Bose has the MOST optical bus?

[Loren]

All the cars built in MY03 and after have fiber optic links (MOST) to the Amps, CD-Changer, and NAV system and radio (CDR-23).

[graylens]

All the cars built in MY03 and after have fiber optic links (MOST) to the Amps, CD-Changer, and NAV system and radio (CDR-23).

This is NOT good news. So if I have the basic factory head unit (no CD changer in the trunk), if I want to replace it I have to bypass the factory amp? Once I get there I (hopefully) have normal wire going to the speakers? Where is the factory amp?

[graylens]

OK, now that I've actually bought the 2003 Boxster S (today! wahoo!), and I can see the amp under the front hood. It appears there are "normal" copper wires proceeding from the amp, so, if I get a new head unit, bring in power from where the amp is getting it (I've read elsewhere that 12v is not even brought down to the center console for the CDR-23) am I golden? Possible complications could be that the illumination, continuous power, ground, etc don't get down to the center console so I'll have to tap those as well.

Of course, I have to bring down the copper speaker wires from where the amp used to be. Is there an adapter available so I could back out to original factory should I ever sell the car (not likely with my current attitude :D )?

Thanks in advance!

[sfarris]

I echo the above. Getting rid of the MOST unit is way troublesome. Try the JL Cleansweep unit. About two hundred bucks cheaper than the Denison ICE unit to add an iPod. Down side is that it makes you control the iPod at the iPod, not at the car stereo. Upside is that it goes in after the OEM amp and you can then power your system with an aftermarket amp. So, you have the factory look with better sound and performance.

[sfarris]

OK, now that I've actually bought the 2003 Boxster S (today! wahoo!), and I can see the amp under the front hood. It appears there are "normal" copper wires proceeding from the amp, so, if I get a new head unit, bring in power from where the amp is getting it (I've read elsewhere that 12v is not even brought down to the center console for the CDR-23) am I golden? Possible complications could be that the illumination, continuous power, ground, etc don't get down to the center console so I'll have to tap those as well.

Of course, I have to bring down the copper speaker wires from where the amp used to be. Is there an adapter available so I could back out to original factory should I ever sell the car (not likely with my current attitude :D )?

Thanks in advance!

You cannot wire in around the MOST system! It is tied to the alarm and ECU, I believe. Changing the stereo will result in socks gettin mismatched in your drawers, and milk expiring before the date on the carton. Don't do it!

[graylens]

You cannot wire in around the MOST system! It is tied to the alarm and ECU, I believe. Changing the stereo will result in socks gettin mismatched in your drawers, and milk expiring before the date on the carton. Don't do it!

Whelp, it looks like I have four options:

1. Get a new HU, bypass the amp, wire direct to the (eventually aftermarket) speakers. Loren, does this have any adverse effect if the stock HU and amp are simply removed? Does the OBD throw any codes?

2. I've heard you can get an Aux-In adapter from Becker Audio. I've not called them yet, and opinions vary on if it is compatible with the CDR-23. Supposedly this cable costs ~$20. This would get me iPod in, but I'd lose playing MP3/WMA CD's or USB thumbdrives, which I could live with but is not as preferable to #1.

3. I could get a high-quality wired FM modulator. Seems fairly cheap, but with the same drawbacks as #2 above, unless Porsche saw fit to make the antenna optical in or some such craziness.

4. I could try a JL Cleansweep or ICE-Denison, but I think this is foolish money for what I get back. I'm not in to controlling my iPod while driving, I just have a few huge playlists I set on shuffle; also, recharging isn't that big an issue since the new ones last 8+ hours on one charge.

Opinions out there? Experiences?

[Loren]

Technically any MOST items that are removed should have them "turned off" using a PST2 or PIWIS tester.

[graylens]

Technically any MOST items that are removed should have them "turned off" using a PST2 or PIWIS tester.

I have a good relationship with an Independent Porsche Mechanic that would probably do this for free or near free. Out of curiosity, what would actually happen to the car were the amp and the stock HU to "disappear"?