I have had my 996tt for 2 weeks and really dislike the audio setup, which I want to upgrade.
I have spent a couple of hours searching this site researching audio upgrade options and although I have picked up lots of good info, I still have a couple of questions that I need help with, specifically about re-using the stock bose amp and speakers.

I have MY02 996tt (Australian model RHD, same as the UK model) with the CDR-220 deck, ie. without the fibre optic setup. I have purchased the Kenwood DNX7100 and still waiting for it to arrive for install which I will DIY. I'm fairly handy with DIY car audio installations having done a number in my younger days but new to the installation tips/traps for the 996. My goal with this system is to add nav/bluetooth/ipod and improve the audio quality, but I dont want to go crazy with the best quality or loud doof-doof bass.

I have found the pinouts for the CDR in the manual, and have taken the amp apart to discover a DSP and what looks to be a fairly weak 4 ch + subwoofer amp. If the DSP is setup to match the speakers then my options are limited to replace the headunit and leave the amp/speakers or replace the headunit, amp and speakers.

I have a number of questions about the stock amp and speakers, as follows:

- Does the DSP in the amp only do the low pass filter for the subwoofer, or does it also equalise the Bose speakers? If it does equalise the speakers, then when I change out the speakers I should change out the amp also.

- Is the quality of the amp reasonable and is it recommended for reuse? (assuming the answer to the previous question is that the amp does not equalise the main speakers)

- Do the speakers have a normal impedance & frequency response or are they non standard (ie. Designed to work only with the Bose amp and visa versa)?

- Does the amp add any delay between the front & rear channels, or maybe even time alignment (via the DSP)?

- Does the DSP head unit drive any speakers or does the Bose amp under the hood drive all speakers?

- Is there a wiring adaptor to connect the standard Porsche plugs to the Kenwood, or do I have to make up a special adaptor (not difficult as I have the pinouts but a wiring harness adaptor would make it easier)?

It looks like my best way to go is to replace the head, amp and speakers, and use the existing wires to the head unit and the amp to connect a new amp where the stock amp is. I also plan to use the existing subwoofer chamber in the rear and swap out the stock subwoofer drivers.

Any tips for decent speakers and an amp (6 channel + subwoofer channel with low pass filter) to replace the stock bits with?

Many thanks for your help.

 

I have a similar setup, I have the Kenwood DDX 8019 with blue tooth and the Video Ipod cable, I went with a JL Audio 6450 6 channel amp.The speakers are MB Quarts, and for the sub I replaced the factory subs in the Bose sup box with JL 6" subs. The car sounds great and has enough bass for me, I'm not a bass head anymore. Make sure you use good wire and keep the interconnect cables away from the power cable.Good luck!I did not have the DSP so I cant really reply to that, but if you do it the way i did it wouldnt matter.

 

So are you powering all the speakers in the car and the subwolfer with the 6 channel amp, or just the mids and highs?

 

The entire car is being powered by the amp, including the sub, the amp has High and low pass crossovers.

 

Thanks guys.

I'll try replacing the headunit first and see how it sounds. The front speakers are not too bad, but the subwoofer in the back sounds so muddy, what were bose thinking....

I suppose you buy a 996tt for the performance not the audio, but having a high quality setup at home, the bose system sounds so colored, and easily beaten by stock systems in much cheaper cars.

I have found the answer to my question about the wiring harness, there is are 2 wiring adaptors you can buy from Metra part number 70-1787 + 70-1784, links below for more info:
http://forums.rennlist.com/rennforums/showpost.php?p=4842458&postcount=10
https://www.6speedonline.com/forums/showthread.php?t=103193&highlight=bose&page=2


Kilrgt, the JL Audio 6450 looks like a good amp for this application and not too expensive. Did you setup the amp to drive the dash and door speakers, with your standard unit driving the rear (which does not need to be too high quality), and bridge the last set of channels for the subwoofer? Although you say the amp drives all your speakers, it does not have enough channels so 2 pair must be paralleled or you are using the head unit amp for a pair.


I'm still interested in any information that anyone has about the DSP done in the amp, and any strange impedance / frequency response of the standard Bose speakers. My setup does not have any DSP functions in the head unit menus, it is only in hardware of the amp, and possibly may only be the subwoofer crossover filters but I don't know.

 

The rears speakers are on the same channel has the door speakers, the only difference is I added resistors so the volume was lower.The rears need to be on but as I am sure you already know just for rear filler.The Sub channel is bridged.

 

Thanks Kilrgt.

Anyone else have any information about the DSP processing in the bose amp, especially if the processing is setup to match the speakers, ie. can the speakers or amp be re-used, or if you replace the amp you should replace the speakers and visa versa?

 

subscribed.

 

I thought I'd follow up with the results of my upgraded stereo install. I used the Kenwood DNX7100, and moved the a/c control to the bottom console. For this I had to purchase a new a/c control surround and new pocket from my local dealer. The a/c control is pretty easy to move (about 1 hour to do it), and I ditched the useless CD carrier as I'll be using a portable music player.

The double DIN unit needs some hacking to fit into the slot for the CDR and old a/c control position, but nothing too drastic. I screwed the DNX chassis into the plastic surround behing the facia once I had adjusted the height / depth for the DNX surround so it looks flush with the dash.

Patching it into the wiring harness was pretty easy, I did not find the right adaptors locally, but with a soldering iron and 2.5mm spades which fit the little sockets for each wire in the plug I built my own wiring harness and did not have to cut the car harness / plugs. The only thing to watch for is the remote amp switch on (Red/Black wire on C1) which goes to the remote amp control on the DNX. I installed the satnav antenna under the little alarm sensor panel at the top of the dashboard, so along with the flush fit of the DNX facia it looks very integrated and if you didn't know you would think it was a factory option.

One tip for people looking to replace the OEM Becker head unit and keep the stock amp and speakers is do not connect the speaker output of your new unit to the wiring harness speaker inputs. The DNX has line outs and having taken the stock Bose amp apart in the trunk, I could see that it accepts both line and speaker inputs on the same wire, and applies DSP and amplification for all the speakers. Using the line outputs from the head unit improves significantly the quality as it is not going through the head unit power amp to be amplified again in the Bose amp. This made an appreciable difference in quality and I'm now much happier with the stock amp and speakers, that I won't bother replacing them, especially as the 996tt is noiser than most when driving. You can also improve the quality of the Becker head unit the same way, by connecting the line outs from the back of the Becker unit to the speaker wires in the harness, but I have not tested this.

I have not seen this documented anywhere on this forum so this is my little contribution to this community .

Two cute things I could do with the DNX, one was use a Porsche wallpaper JPG as a background, and another was hard wire my gate remote control into the spot where the satnav antenna and alarm sensor goes. The DNX has 2 external control soft switches that can be accessed via a hotbutton, so I now have integrated gate open / close soft buttons which work well. I had to add a little DIY electronics (relays and diodes) to make this work.

The satnav works pretty well once I upgraded to Aussie maps as I bought the unit Stateside and it only had US maps. The user interface is a little clunky but functional and easy to use once you get use to it.

All in all this took about 8 hours of work, most of the time futzing with dash to take it apart. I think I could do it in 3 hours if I had to do it again

 

Attached are pictures if you are interested in how this looks. I have yet to do the final adjust of height and fill a gap below the unit, but even now it looks decent & integrated, almost factory. It also makes the car seem much newer.

 

Can you please tell me model # you used for subs and speakers.
Thank you.