Base stereo technic harness

Omp · 07-29-2021, 01:41 PM

Hi there, new to the forum and I've been doing a lot of research around upgrading my stereo in my e91, I currently have base audio with Pro nav and it just isn't cutting it.

A friend of mine who has more audio experience than me says that I can run a 5 channel amp and take a high level input for the amp from the back of the stereo, run it to the amp and then run from the amp to my underseat subs bridged, then outputs to front door speakers and tweeters. Will this work?

I then read that there is a harness made by technic, I don't really like the idea of cutting oem wires, is this the only reason people buy the technic harness? Just because it saves splicing and running new wires? Could I just get an extension that sits between my stereo and factory wiring and splice into that so that I can just remove it and put it back to standard when I need to?

Help would be much appreciated.

OMP

ctuna · 07-29-2021, 02:12 PM

Omp · 07-30-2021, 01:15 PM

Thanks for the reply buddy, sorry I should have made it clear that I will be replacing the speakers in the doors and adding tweeters to a currently tweeter less system a d be adding new woofers in the casings under the seats, I will then be adding an amp as I don't have one from factory being base audio. I've been through most of them threads already that you've linked, like I say I've been doing my research but needed mainly to know if the technic harness is a necessity. I know people buy it to prevent splicing and make it plug and play but what exactly do you get in terms of wiring? I've been through the site but it doesn't exactly clear it up... If I buy one with rca terminations does that mean wiring from the head unit will be converted to rca for the amp input and then there will be open ended wires in the supplied loom that will go from the amp and will then link back up to the head unit loom again? Thanks for any help

ctuna · 07-30-2021, 03:39 PM

You should be able to read the explanations on his site.
He describes what they do in detail and what is required to
install them. If you have a basic understanding of electricity and have
ever delt stereo installations you should be able to understand it.

He has three different harnesses .

The first thing is to totaly understand the wiring and the bad eq curve
coming from the stock radio. This is well explained in the E90 Base Stereo Guide Link.

There are no RCA's from any BMW head unit.
You use the Front Left and Right channels to drive the new amp you may use the Rears to drive the
map if you are running the rear speakers off and amp.

The signal from the from the Head unit is a differential signal (speaker outs or reduced speaker outs
if recoded to Hi Fi ) this means no common ground and your amp has to able to accept differential signals.

Omp · 07-30-2021, 04:24 PM

Again thanks for the reply, as for the site is pretty bad on descriptions. Each item says what it does yes, but it doesn't say what's included other than in the 4/6 harness. If each item was written in the same format so I could work out the differences between each it would make things a lot easier. Also no explanation as to what it means by termination, regarding rca or normal. I explained in my last post as to what I believe this means but can't be sure without someone telling me I'm right or wrong. I'm based in the UK so I need to be sure before I order as it will take its time to get here plus it will incur charges, so also not straight forward sending it back.
I understand the base stereo is heavily eq'd and I will most likely be getting the stereo recoded as I've read this can sort it out and potentially run a processor. I understand the base stereo puts out a full range from the head unit. My understanding becomes limited more in where the technic harness fits into the factory wiring, what connection types I need to use and where in the technic harness these connector are.

bmw335ie90 · 07-31-2021, 05:03 PM

Quote:

Originally Posted by Omp

Again thanks for the reply, as for the site is pretty bad on descriptions. Each item says what it does yes, but it doesn't say what's included other than in the 4/6 harness. If each item was written in the same format so I could work out the differences between each it would make things a lot easier. Also no explanation as to what it means by termination, regarding rca or normal. I explained in my last post as to what I believe this means but can't be sure without someone telling me I'm right or wrong. I'm based in the UK so I need to be sure before I order as it will take its time to get here plus it will incur charges, so also not straight forward sending it back.
I understand the base stereo is heavily eq'd and I will most likely be getting the stereo recoded as I've read this can sort it out and potentially run a processor. I understand the base stereo puts out a full range from the head unit. My understanding becomes limited more in where the technic harness fits into the factory wiring, what connection types I need to use and where in the technic harness these connector are.

The technic harness goes in-between the normal car harness and the head unit. Disconnect the original head unit harness, plug that into the technic harness, and then plug the technic harness into the head unit. If you have a CIC it is VERY difficult to fit the big ass harness in while still leaving room to slide the head unit back in.

The technic harness allows you to grab the 4 channel output from the head unit. You have to run the cables (including remote turn on) all the way from the head unit, under the carpet to the trunk. It comes with everything you need as far as wiring goes. I highly suggest the twisted pair RCA termination option on the harness and coding the head unit to HIFI.

You could cut into OEM Quadralock harness and splice wires in if you don't want to buy the harness. Just need to splice 8 wires and find somewhere to grab a remote turn on signal. The harness does all this for you without the need to cut or solder anything.

amolvin · 08-15-2021, 03:12 AM

on my E90 , there are no multifunction buttons on the steering wheel. it is a base version.
Could we just add a upgraded steering wheel only or do we need to change some code ?

07-29-2021, 01:41 PM	#1
Omp New Member 0 Rep 5 Posts Drives: E91 330d Join Date: Jul 2021 Location: UK iTrader: (0)	Base stereo technic harness Hi there, new to the forum and I've been doing a lot of research around upgrading my stereo in my e91, I currently have base audio with Pro nav and it just isn't cutting it. A friend of mine who has more audio experience than me says that I can run a 5 channel amp and take a high level input for the amp from the back of the stereo, run it to the amp and then run from the amp to my underseat subs bridged, then outputs to front door speakers and tweeters. Will this work? I then read that there is a harness made by technic, I don't really like the idea of cutting oem wires, is this the only reason people buy the technic harness? Just because it saves splicing and running new wires? Could I just get an extension that sits between my stereo and factory wiring and splice into that so that I can just remove it and put it back to standard when I need to? Help would be much appreciated. OMP
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07-29-2021, 02:12 PM	#2
ctuna Lieutenant General 1911 Rep 13,102 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	The subject of the Base stereo is well covered The subject of the Base stereo is well covered if you search a little bit. https://www.e90post.com/forums/searc...rchid=69969851 Do an advanced search with Base stereo in the title limited to this subforum. http://www.e90post.com/forums/showthread.php?t=495855 Base system upgrades http://www.e90post.com/forums/showthread.php?t=445266 http://www.1addicts.com/forums/showthread.php?t=634957 http://f30.bimmerpost.com/forums/sho....php?t=1003810 http://www.e90post.com/forums/showthread.php?t=822366 http://www.e90post.com/forums/showthread.php?t=581379 http://www.e90post.com/forums/showthread.php?t=451941 http://www.e90post.com/forums/showthread.php?t=540954 http://www.e90post.com/forums/showth...ghlight=Dotech http://www.e90post.com/forums/showthread.php?t=495855 http://www.e90post.com/forums/showthread.php?t=494299 http://www.diymobileaudio.com/forum/...morel-jbl.html http://www.e90post.com/forums/showth...ht=amp+upgrade http://www.bimmerfest.com/forums/sho...d.php?t=550771 http://www.e90post.com/forums/showth...1#post16679904 http://www.e90post.com/forums/attach...1&d=1411521234 http://www.e90post.com/forums/showthread.php?t=1378833 base system wiring pre/post 3/09 http://www.e90post.com/forums/showth...1#post16679904 You have to know something about the base system wiring. The front floors and doors are wired in parallel running of the front channels of the Head Unit. The base system speakers are not designed to take much power and are not very good. Since there is no tweeters the eq for the front channels is boosted a the high end. The parallel wiring in the front is either made at the underseat speaker or in the door sills. BMW stereo types http://www.e90post.com/forums/showthread.php?t=352586 http://www.e90post.com/forums/attach...2&d=1266451970 http://www.e90post.com/forums/attach...2&d=1260829447 http://www.e90post.com/forums/attach...1&d=1209780865 http://bmwcoders.com/forum/3-er-8/bm...1-e92-e93-291/ http://technicpnp.com/menuDiagrams/d...e90_92_93.html http://www.musicarnw.com/page-2/ http://www.e90post.com/forums/attach...3&d=1169133185 http://www.e90post.com/forums/attach...1&d=1209780605 http://www.e90post.com/forums/showthread.php?t=641323 http://www.e90post.com/forums/attach...4&d=1278871872 http://www.e90post.com/forums/showthread.php?t=343673 https://www.bimmerfest.com/threads/e...n-752.1275694/ base system wiring pre/post 3/09 http://www.e90post.com/forums/showth...1#post16679904 Base System Guide http://www.e90post.com/forums/attach...5&d=1493273253 You could do your own wiring but it won't be as nice as a Technic Harness and there is a greater screw up factor. The underseats and the front door speakers should be replaced at a minimum and added tweeters. I would do a 6 channel amp if you are going to amp the rear channels and 4 channel if you are going to not do the rear channels and keep the Front speaker all on separate channels . The underseats are not sub's they are mid bass ( not even that on base system just total crap) Read this first. http://www.e90post.com/forums/attach...5&d=1493273253 Last edited by ctuna; 07-30-2021 at 03:39 PM..
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07-30-2021, 01:15 PM	#3
Omp New Member 0 Rep 5 Posts Drives: E91 330d Join Date: Jul 2021 Location: UK iTrader: (0)	Thanks for the reply buddy, sorry I should have made it clear that I will be replacing the speakers in the doors and adding tweeters to a currently tweeter less system a d be adding new woofers in the casings under the seats, I will then be adding an amp as I don't have one from factory being base audio. I've been through most of them threads already that you've linked, like I say I've been doing my research but needed mainly to know if the technic harness is a necessity. I know people buy it to prevent splicing and make it plug and play but what exactly do you get in terms of wiring? I've been through the site but it doesn't exactly clear it up... If I buy one with rca terminations does that mean wiring from the head unit will be converted to rca for the amp input and then there will be open ended wires in the supplied loom that will go from the amp and will then link back up to the head unit loom again? Thanks for any help
	Appreciate 0 Quote

07-30-2021, 03:39 PM	#4
ctuna Lieutenant General 1911 Rep 13,102 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	You should be able to read the explanations on his site. He describes what they do in detail and what is required to install them. If you have a basic understanding of electricity and have ever delt stereo installations you should be able to understand it. He has three different harnesses . The first thing is to totaly understand the wiring and the bad eq curve coming from the stock radio. This is well explained in the E90 Base Stereo Guide Link. There are no RCA's from any BMW head unit. You use the Front Left and Right channels to drive the new amp you may use the Rears to drive the map if you are running the rear speakers off and amp. The signal from the from the Head unit is a differential signal (speaker outs or reduced speaker outs if recoded to Hi Fi ) this means no common ground and your amp has to able to accept differential signals. Last edited by ctuna; 07-30-2021 at 03:51 PM..
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07-30-2021, 04:24 PM	#5
Omp New Member 0 Rep 5 Posts Drives: E91 330d Join Date: Jul 2021 Location: UK iTrader: (0)	Again thanks for the reply, as for the site is pretty bad on descriptions. Each item says what it does yes, but it doesn't say what's included other than in the 4/6 harness. If each item was written in the same format so I could work out the differences between each it would make things a lot easier. Also no explanation as to what it means by termination, regarding rca or normal. I explained in my last post as to what I believe this means but can't be sure without someone telling me I'm right or wrong. I'm based in the UK so I need to be sure before I order as it will take its time to get here plus it will incur charges, so also not straight forward sending it back. I understand the base stereo is heavily eq'd and I will most likely be getting the stereo recoded as I've read this can sort it out and potentially run a processor. I understand the base stereo puts out a full range from the head unit. My understanding becomes limited more in where the technic harness fits into the factory wiring, what connection types I need to use and where in the technic harness these connector are.
	Appreciate 0 Quote

08-15-2021, 03:12 AM	#7
amolvin New Member 0 Rep 6 Posts Drives: E90 Join Date: Aug 2021 Location: Mauritius iTrader: (0)	on my E90 , there are no multifunction buttons on the steering wheel. it is a base version. Could we just add a upgraded steering wheel only or do we need to change some code ?
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