Fed Up with Stock AMP: Replace HU or Steam Ios?

[jjcuff1]

I have a 07 M35 with the mid level bose with navigation. 8 speaker system
I added 2 alpine class d amps with a kicker l3 sub and a 4 channel alpine using an audiocontrol lc8i for line converter/preamp from the stock HU

I highlighted this on another thread. My stock speakers cut off over bumps using the radio and stock headunit but in bypass mode plugging into the lc8i with my phone and jack the stereo is fine. It is loud and hits hard. The Line In jack from my iphone is weak so the volume is low with gain at half way but still clean.

Back to the radio the and the speakers cut off or drop to 5% volume levels. If I bump the volume up to 30% they kick back on. It is a cycle any or all speakers will cut off randomly but especially over bumps or turns.

I know it is not after the LC8i now so i will pull the stock amp out and check for wires. But the fact it is the whole system
leads me to believe I have an impedance issue, which audio control suspects, or channels are blow. I do hear static and pops on one channel it comes and goes but it is the weaker sounding channel so I suspect that one is going but I tried splitting it with the rear channel the problem of cutting off still persist! crazy.

So even if it all worked it still wasnt as good as an aftermarket headunit. So anyone replacing the stock HU and not losing the cars features or installing elsewhere another HU to operate from?

Or using my iphone and going with tunein app for live radio? the problem there it is so unsafe to keep using iphone and the headphone jack and the volume knob is seperate for the aux in is so akward for daily use. Right now I max out the volume then control from the iphone.


I am thinking cost wise simple solution is try to mount iphone in front of the car stock HU when I am driving so I can touch screen and navigate volume. I did see there is a 3rd party touchscreen overlay that will allow you to send your IOS screen to the stock HU screen and you switch displays? Or using a MIMO usb touch screen I can place in that location with a flip down rig so I can accessthe stock HU as needed and put the mimi plugged into my iphone as the stereo remote control so to speak?


Anyone do any options for IOS control or replace/add stock HU once the amp is gone.

Anyone replace their stock amp with a repaired one or had it modified for better power handling out with good success. I feel if I by a replacement amp it will give me same results and fail again or possibly have same issues.

[svard75]

Did you read my last post in your previous thread? There is specific instructions on how to setup the LC8i in that you have to adjust the HU volume to 3/4 and then adjust the peak input settings on the LC8i. After setting that adjust the amp gains and you're good to go. One more thing to remember if you have Audio Pilot turned on your system will automatically increase the bass volume to compensate for the noise in the cabin. Turn audio pilot off in your situation and then adjust the LC8i as per above.

Let us know if that helped. This is interesting and I'm sure plenty of people out there would love to upgrade their stock systems.

[jjcuff1]

Yes I did that twice. Volume is not a problem neither is gain. The speakers just cutoff like down to dead whisper then pop back on. I will pull the trunk liner and look for short in the wires between stock amp and lc8i. I might bypass the lc8i as a test and just connect directly to the speakers again like stock.

I think i need resistor across the channels or check polarity otherwise I will return the lc8i and go back to stock amp and crappy sound output. but at least it worked.

[svard75]

too bad! You turned off audio pilot too in the HU settings? Well they officially screwed us (infiniti that is). I doubt it's impedance. Are any of the wires shared or crossed for this setup? Are you using two of the same speaker wire for two different inputs on the LC?

[mexillis]

From your last thread it sounded like you had lots of wires going everywhere. Which speakers cut out, subs only or all? How did you tap into the stock amp again? There have been plenty of people who have installed aftermarket amps without a problem either base model or with the 14 speaker system.

[svard75]

Mex I think his problem could be polarity as he suggested. If you have one speaker connected properly and the next reverse then the lc8 could be grounding the stock Bose causing it to enter protection mode. I'll post the schematics of the stock amp with wire identifiers hopefully it'll display polarity.

[svard75]

Checked out the diagrams and check your wires from the stock amp to the LC.

The following is found on the connecters on the BOSE amp. I've never seen them myself but according to the schematics there are two connectors close to each other one slightly larger than the other. These pins begin at number 41 and end at number 77. The smaller connector has 14 wires. The larger connector has 23 wires.

Center Speaker
+ O/B pin 57
- W/R pin 58

Rear Surround LH
+ B pin 59
- W pin 72

Rear Surround RH
+ G/Y pin 62
- GY/R pin 73

Subwoofer
+ BR pin 45
- B/R pin 46

Front Left Door speaker set. The tweeter is connected in parallel to the midrange.
+ L pin 41
- B/W pin 42

Front Right Door speaker set. Same setup in parallel
+ BR pin 43
- B/R pin 44

Rear Left Door speaker
+ LG pin 54
- B/Y pin 49

Rear Right Door Speaker
+ O pin 68
- B/P pin 55

Key for wire colour
B = Black
W = White
R = Red
G = Green
L = Blue
Y = Yellow
LG = Light Green
BR = Brown
OR = Orange
P = Pink
PU = Purple
GY = Gray
SB = Sky Blue
CH = Dark Brown
DG = Dark Green
When the wire colour is striped, the base colour is given first, followed by the stripe colour as shown below:
Example: L/W = Blue with White Stripe.

[jjcuff1]

Yes I will take a look at that this weekend.

I think polarity and/or some ground issue between the LC8i and the Stock unit are causing any bump or wire to ground out and short the speakers. As I crank it up I add captiance to whatever circuit or caps in the stock amp can hold until they discharge (ie ground out) and then the stock amp sees no load and it cust off again.

Endless cycle, Ground loop isolation problem?

Here is my sketch

[jjcuff1]

Thanks for that wiring. Man I know from what I can see they are off. I mean he matched up blue and blue brown brown etc.

From above you have different colors for +/- per channel could be my big problem!

Dam installers

[svard75]

Hey, I apologize the wiring readout is for a 06 with the Bose 5.1 system. I got it off alldatadiy website based on a subscription. Before rewiring the lc maybe check a 07 AV-AV diagram to verify. They may have changed wire colours between model years.

I would not consider that the wire colour at the speaker is the same at the amp. The door speakers connect from the smj (super multiple junction). Same with the centre.

[TDot]

You simply have a short somewhere/wires not properly spliced/connected, nothing beyond that. I didn't read your entire first post so I can't fully comment.
But yes you can retain your audio functions of the navi and phone and put in a whole new system which I highly recommend. All you have to do is insert an auto audio switch between the Bose amp your new system and the speakers. It's easy the part cost about $100 and you'll need 2, unless you can find a four ch version. You play your music through your new system, the device picks up audio from the Bose and automatically switches, when audio is gone it switches back. For the life of me I don't understand how people spend so much money to "improve" this car's audio and leave this amp still running(but I'm not getting into this again)....with the consideration of wanting their nav and phone and not knowing about auto switches.
I am not 100% but i believe the schematics of the 08 is the same as 07, if it is download the 08 av field service and go to av-277 and the colors there on the output are the same at the speakers. You can match up.
Good luck.

[jjcuff1]

Well i think problem solved!

I pulled out liner ans traced allthe wires polarity was right only thing tht is odd is the subwoofer and front right wires have excr same colors and are next too eaxh other on the acematic fsm but the schematic is actually backwards or upside down because no way they match up in the pin out. Colors are the ama though.

So i pulled all splices for tightness moved bundle. They were all tight and appeared hung up on the brackets and the power was pinched between the plastic snaps of the trunk liner

I found only 1 wire. The front right speaker the ine with the worst problems
Had a nick in the shielding it was not grounded but u could see copper

I didnt think it was issue but maybe in tight bundle it was arcing or groundig?

Anyway after that all speakers over bumps work great and stereo really aounds 10x better and super bass! My bluetooth phone recpetion is now crystal clear again!

I hope it stays that way

[svard75]

Awesome! Good job.

[jjcuff1]

Well after many attempst I still had problem. Long story short; Using a lc8i i bypassed the rears from stock amp, leave them disconnected and clipping stops for most part except on centter and bluetooth calls. The fronts are blended with teh rear and subs now and all signals come from the fronts to the rear. All 4 speakers now play with clipping over bumps.

The overall sound quality is still not good sounds sound stage is goofy. But it is ok. The weird thing is the fronts get NO BASS signal. 1 click of phase to the fronts and sub cuts off. maybe that channel is blown too within the amp on the fronts