Nosoup4u

I am 99% sure my rear subwoofer is not working. It is a 2003. The PO upgraded the head unit to a Alpine DVA-310.

I plan on adding an auxiliary output to connect my iPod; but, I noticed that there really is no bass at all. I am not looking to put focals or anything like that. I did a search and it appears some of you guys simply swapped head units - but, were able to get the bose amplifier and stock speakers to work. Since I need to pull the HU out ... what should I be looking for? Is it the scenario where the amplifier was bypassed and HU is powering the front speakers and side? So, how do I get the subwoofer back? Most everyone is replacing speakers ... not looking to do that.

Is there a write-up or link? Spent the past hour searching with no luck here ....

I also tried to write crutchfield .. since it seems I could power at least 4 speakers with the head unit (18w RMS x 4). This was their response below. Surprising.

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I'm Nick. I checked on this for you, and I'm afraid I don't have any research information on your '03 Porsche at this time. Any installation will have to be completely custom. I wish I had better news for you there. If you'll please pass along some information on each speaker location (size of the factory speaker, mounting depth, and mounting height (from the speaker mounting surface to the bottom of the overlying panel)), I'll be glad to compare and pass along some great recommendations.

Kevinmacd

Think starting in 2003 the interfaces are different than the pre 2003. The bus is called MOST fiber optic. In order to change out the head unit I am pretty sure the BOSE amp has to go.
Here is a post that might help you.

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

Gern

I have an 02 with Bose, so it's pre-MOST, but I went through a similar experience. In my case the head unit is a Pioneer AVIC, and it had no bass. PO had a two channel amp in the trunk. It turns out that the sub was not powered, and the two channel external amp was powering the door speakers. The dash and back seat speakers were being powered by the head unit (25wpc I think).

I now have a 5 channel JL Audio amp powering dash, doors and sub and the left over Kenwood two channel powering the back seat speakers. The stock dash speakers were upgraded, but I'm using the stock speakers elsewhere. The system sounds very good, particularly considering the poor sonic environment of the car. I am very happy with the system, and I wouldn't do much more to it. The car is inherently too loud to spend a lot of money on a system, IMHO. This was a relatively cost effective way to get really good sound.

mikewils

Kevin - If you rewire the subwoofers in series and replace the head unit and amp, what kind of amp would you need and would that mean that the factory speakers can still be used? I wanted to get a new head unit until my local place said that everything would have to be replaced, which I wasn't about to do. THanks much!