2002 745i System Install?

[TalonTsi97]

Hey guys! Ive looked at a lot of the forums and read up on a lot of information on how to do this, but im still very confused on it. All im wanting to do is add an amplifier and a set of subs at minimal cost and confusion. Ive read up on the Req5 (no longer available). Ive read up on LOCs but dont know which ones work, what they look like, or how they are wired in. Im basically requesting an idiot's guide on how to install a system on a 745i. Thanks again fellas!

[White94RX]

It's really a very simple procedure. Wire in the amplifier to power, ground, and a keyed power source like you would in any car. Then use the speaker-level inputs on your amp (if it has them), or buy a speaker-level to RCA conversion box, to get the audio signal from your factory amp to your new amp. I did this on my E60, and my E39. A wiring diagram of the factory amp will help you tap into the correct wires for the audio signal.

[DennisCooper]

Hi,

You can install a basic level upgrade and have what you want relatively easily. The 'usual' audio result is a mismatch as the amplifier and subs used either overpower the cabin speakers or, if the ski hatch or 'vent' to the cabin isn't done, the sub bass is 'locked' in the boot/trunk and all you get is vibrational bass in the cabin.

The quality method of doing what you are thinking is to use a sound processor which takes all the outputs from the OEM amplifier and uses clever electronics to 'clean' the dirty signal - by this I mean it'll only output a non distorted signal, boost it's voltage, and remove the factory set Equalization curve as best it can. That 'clean' signal is fed to a 5 channel amplifier where you upgrade the front speakers to 2 way components (or 3 way ) and the rear speakers to 2/3 way co-axials. A 8/10/12 inch subwoofer in a small sealed enclosure to let the subwoofer 'vent' into the cabin is then added. The result is a much cleaner, better and accurate level of sound quality with excellent sub bass performance that's efficient, controlled and musical. The rest of the speakers will then also have enough power to be driven well and the complete audio spectrum is reproduced with balance and would be well matched.

The quality method costs more overall, but can sound fantastic and also provides you with excellent performance Vs money spent ratio. The basic method is cheap, but doesn't sound anywhere as good overall.

I'd also suggest you contact local reputable car audio installers who'll be able to advise you on the above and install what you purchase both correctly and most importantly, safely. I recommend this route as from your post it sounds as though you don't have much experience installing 12V electronics in such a way.

Cheers, Dennis!

[TalonTsi97]

Thanks for the replies guys! White94RX, the way you stated is the way im looking at doing it. $$$ is very tight but this car really has zero bass atm. Im also looking to replace the subs below the seats at some point in time as well. Thanks for your input as well Dennis. I know there is a much higher quality of way of doing this but it doesnt fit my budget at this time. Im looking for the simplest method that i can do without worrying about hurting/destroying the idrive, logic7, or anything else attached to this lol! Ive installed systems before, but never tapped into wiring like this before! Any pics or idiot proof write-ups you guys have would also be very helpful...thanks again!

[matt@bavsound]

I think you may find that going into this without the proper info or help (from a good car stereo shop) may end up costing a lot more in the long run than just doing something a bit more straightforward like swapping out the underseat subs first before you attempt adding an amp and subs to the factory system. One big problem with the E65 is the lack of options when it comes to the remote turn on source for the amp. Some E65s have an ignition wire that can be found in the trunk, but it is tricky to find without some prior knowledge and a multimeter. Unlike older BMWs with a simple white remote wire at the factory amplifier, the OEM amp in your E65 is controlled by the MOST ring, so this wire isn't present.

You can of course use a sub amp with signal sensing to automatically turn on when audio is playing to avoid this trouble, but they don't necessarily always work as advertised...

That said, the best place to catch signal if you're not going to use a processor is the factory sub wires coming from the OEM amp. They are larger gauge twisted pairs (yellow and blue) in the amp harness. You should be able to find wire colors in the forums with a bit of searching, but I'd strongly suggest not going straight to adding a sub in the trunk without any other modifications, as you'll likely be frustrated and disappointed with the outcome.

Let me know if we can help!