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Subject: How to replace your DSP Amp with an aftermarket unit. Author: 740sporter as Stu : member since June, 2005 : 5192 posts Posted on: 2006-04-30 22:37:30

Folling is my procedure for circumventing the DSP Amp and installing top quality speakers up front to handle the additional power. When and if you do this the advantages are:
1. More power(louder!!)
2. Cleaner sound
3. Retain Steering wheel controls
4. Retain CDC funtion/control

Disadvantages:
1. No DSP
2 Not fadeable without running rear channel from head.

Anything you do to your car is your responsibility. I take no responsiblitiy for your actions as this post is a procedure I performed after extensive research and tested on my own vehicle. Hate to be a stick in the mud, but, again, what you do to your car is your responsibility!

This procedure was performed on a 99 740iS Non-Navigation. The same procedure will work for the Nav vehicles as well as i'm told but I cant garuntee it will work as I have not performed the operation myself. Guinea pig anyone?

The first section pertains to replacing the front door speakers with Diamond Audio HEX Components. I switched out the 5.25 woofers (after some dremmel action) and replaced the stock midrange with the component tweet. After the new amp is up and running the Super tweeter in the stock system will no longer be utilized ( this is great cause it destroys the front stage in the stock DSP system anyway).
This is a pic of the new woofer next to the old and the speaker box that mounts to the inside of the door. To remove the door panel, refer to E38.org

This is the woofer installed in the box.

This is the box reinstalled in the door.

This is a closeup of the HEX crossover and the component tweeter.

Here is the tweet installed in the pod. Note the original next to it

And tidily installed in the door. Note the tweeter is secured with a piece of bailing wire using the original speakers' mounting screws.

When wiring your aftermarket components, by all means use the factory wiring. Just check, double check, then check again that you got the polarity correct on the speakers. If you get one +/- wrong out of the 20 connections you will make, your sound quality will be compromised.
Here is a basic schematic of my system.

The Alpine amp pictured is actually a 4 channel amp but I am using it in 2-channel(bridged) mode. The HEX crossovers feature a RAF channel (rear audio fill) that you can connect your rear speaker crossovers to. This allows you to put most of the power to your front stage but also have an adjustable image via the crossover for the rear passengers as well.
The way the BMW system is set up from the factory you only have the front channels available to tap in to at the DSP amp connection via the stock harness. Keep in mind that through this process I did not have to run one single wire from the front to the rear. If you wish to run a 4 channel amp however, you will have to tap in to the rear channels at the radio up front. The pin designations for those rear channels on the tape deck or NAV unit up front are:
RR+ Pin 6
RR- Pin 14
LR+ Pin 3
LR- Pin 12
I plan to do this eventually as well but will wait till the Sirius/Ipod install so I wont have to tear the interior up more than I have to.
Here is the board I created for my expirament. All of these compnents will eventually be discreetly mounted inside the trunk. The board is just for ease of installation/removal during the tuning process.

The board simplifies (if thats possible lol) the installation by breaking it down into 3 sections.
1. Input 4 connections
2. Output 16 connections
3. Power supply/ground/REM

The second amplifier is for the subwoofer. You will notice in the next few pictures a Bazooka tube. That unit is self powered and helps greatly with the stock system, but it will soon go away. I actually turned out using the Alpine for the room speakers and will use the Planet for the 12" Sub to be built in a custom fiberglass box where the old Amp/CDC were. You may notice that the board was initially wired to the Planet in the pictures but after firing it up, 200/Channel was too much for the Component speakers.
Here are the wire taps I used for all of the speaker connections. How fitting that I took the pic of them on top of the DSP amp. Get the Red ones. Wire size 18-22ga.

Here are the pin outs/connections. This is where it gets rough. This takes some serious patience. I have been working on car stereos for about 15 years and this part of the process took me 4 hours to complete. You have to make sure every connection is perfect. Double and triple check before tapping/cutting. Verify with your multimeter as well. The only saving grace in this is that on the 18 and 26 pin connectors there is a sliding lock mechanism that easily slides out. You will then be able to plainly see a very small number next to each and every pin that it is assigned to. Thanks to our own DavidC for this crucial and 100% accurate information.
BMW DSP Amplifier Pin Designations
If your car is out of warranty and you dont plan to reverse the system, dont be afraid to cut the plugs as that would be the easiest and highest quality connection. Keep in mind if you do so though, there will be no turning back and it will potentially hurt you come resale time. I just diddnt want to cut anything at this point. I will probably go that route and solder each connection upon permanant implementation of the system as I plan to keep this car till it is junkyard time.
Heres a shot of the board all wired up and installed.

And a couple of shots of the Taps in place. Looks like a sideways plate of Spaghetti!


No more DSP Amp.


The CDC is still in place and funtions perfectly. When you unplug the DSP amp the CDC automatically defaults to its wiring harness to the input in the front instead of sending its signal directly to the DSP amp via the digital Coaxial cable. The CDC will go next weekend in favor of an Ipod/Sirius and the space will be used for an Alumapro 12" sub in a custom enclosure. More on that to come.....

Stu

• How to replace your DSP Amp with an aftermarket unit. (pic) (url) - Stu 2006-04-30 22:37:30 (37913 views)
  • so Stu, got any factory DSP speakers you want to sell? - JohnG 2006-05-01 17:42:39 (685 views)
    • Abosolutely. all of the speakers are perfect. (nt) - Stu 2006-05-02 15:48:29 (695 views)
      • Shoot me an email. (nt) - Stu 2006-05-02 15:50:24 (439 views)
        • e-mail sent (nt) - JohnG 2006-05-03 14:52:20 (407 views)
  • I just went to listen to my car as they were adjusting the crossovers. (nt) - Tony K 2006-05-01 15:43:25 (820 views)
    • hit enter too fast - Tony K 2006-05-01 15:44:39 (599 views)
  • what kind of wires R those grey sleeve ones? they don't look like speaker wires? (nt) - LA-Sean 2006-05-01 13:49:45 (598 views)
    • 16 guage 2 conductor industrial speaker wire. (nt) - Stu 2006-05-01 14:06:55 (723 views)
  • Just found this amp. NE1 have expirience with it? (url) - Stu 2006-05-01 12:39:38 (943 views)
    • Stu, Did your 7 come with shadowline, or DIY ? (nt) - Blue740i 2006-05-01 14:07:19 (589 views)
      • Stock Sport model. Shadowline, 3:15, Highstall, Winter, Steptronic (nt) - Stu 2006-05-01 14:11:07 (567 views)
        • Thanks (nt) - Blue740i 2006-05-01 14:20:08 (379 views)
  • My car is in the shop now having the same thing done. - Tony K 2006-04-30 22:59:45 (615 views)
    • Tony, when do you get yours back. Why diddnt you go with a 500/5? (nt) - Stu 2006-05-01 15:22:06 (600 views)
      • Tomorrow. I already owned a 300/4 from my MINI and had a 500/1 in the 7 (nt) - Tony K 2006-05-01 15:50:57 (528 views)
    • I was thinking 'i wonder how Tony's car is coming along' while - Stu 2006-04-30 23:02:41 (559 views)