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Hi All,

I've decided to replace the original Blaupunkt HU with an 2DIN Alpine. Also, I wanted to keep the BOSE system.
The new HU is already installed and there's sound coming out from all the speakers, but not everything is OK:

- There's always a static noise in the background even when the volume is at 0.
- When I press Mute, the volume fades away, but not entirely. I can hear clearly the music playing.
- Also, it seems it's transmitting too much power to the speakers, as the sound distorts more easily.
Looks like the HU is sending the signal directly to the speakers without going through the BOSE amp.

I believe everything it's correctly wired. I've followed "shiny_car"'s tutorial (thank you :)), and connected the blue wire - labeled "REM" to the blue wire of the car. This should power up the BOSE amp.
I still haven't connected with the RCA's as I couldn't get the adapter yet.

Now my doubt is:
There is a cable with a yellow connector that was connected to the original HU, and now it doesn't have anything to connect to.
Could this be the BOSE amp energy cable?



Another doubt is the black box underneath the original HU.
I don't know if this would be the BOSE equalizer or just the Blue&Me module.
The only label says Magneti Marelli (?!)




If I start the engine with this box disconnected, the KM's start flashing. What is really the funcion of this box?

Thank you for your help and Merry Christmas to all :)
 

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- When I press Mute, the volume fades away, but not entirely. I can hear clearly the music playing.
i have the same thing in my mito (no bose, only b&m) Not sure what this causes, mute is set to 0db in the settings on my pioneer.
I believe the box is the blue&me unit. I had to get other canbus cables for my steering wheel to the headunit to also stom KM flashing.
 

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Depending on what headunit you have the mute button might just activate the "attenuate" function (as it does with my kenwood) which just reduces the volume but doesn't turn it off completely.

The black box is indeed the B&M unit. The flashing odometer indicates a CANBUS error because you've unplugged the B&M. As far as i know the only way of alleviating this is to plug the unit back in - i've managed to hide mine up behind the dash just to the side of the glove box.


I've had a look at shinycars info on bose systems and from the looks of things the reason you're getting distortion is that the BOSE amp is expecting a low level signal on the speakerwires, but is actually getting a high level feed from the HU - the HU is sending an amplified signal to the amp which is amplifying it again. Potentially you could be doing alot of damage to your amp if you run at high volumes with this setup so I would recommend waiting till you get the RCA adapter if possible.
 

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Thank you adruss85.

It makes sense, as the sound is distortet and amplified indeed.
I'll see if tomorrow I can get the ISO->RCA cable.

In the meantime, one doubt still remains :)
What is that cable with the yellow connector?

I've checked with 2 friends with Mitos which don't have Bose, and they confirm their HUs don't have this connection..

Thanks
 

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In the meantime, one doubt still remains :)
What is that cable with the yellow connector?
Hi Pereiraruialves,

The radio in my MiTo 155TB has the same two connections (black and yellow) located at the rear of the unit as yours, unfortunately I can't find the purpose of both connections. I know this is an old discussion, but did you eventually find out where the connections are for?
 

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The two connectors are actually two separate antennas. The black one is on top of the car, while the yellow one is supposed to be somewhere in the body frame if I remember correctly.
 

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I suspect, because you are using the speaker outputs of your aftermarket radio, you are overdriving the Bose amp.

On the standard Alfa factory radio's, there's a signal input pin on the radio that tells the radio it's part of a Bose configuration. The speaker outputs of the radio are then changed to hi-level line outputs.

Standard radio's do not support this, so you either have to use the line outputs of the HU, and connect these to the original speaker loom connections, or use an adapter to convert the speaker output to hi-level line output.
Potential problem here is that Bose requires a hi-level line input, preferably in the order of 6 Volts....

the yellow mini-iso connector contains the trigger wire for the Bose amp. +12 switches amp on, zero volts (not connected) switches off.
 

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I suspect, because you are using the speaker outputs of your aftermarket radio, you are overdriving the Bose amp.

On the standard Alfa factory radio's, there's a signal input pin on the radio that tells the radio it's part of a Bose configuration. The speaker outputs of the radio are then changed to hi-level line outputs.

Standard radio's do not support this, so you either have to use the line outputs of the HU, and connect these to the original speaker loom connections, or use an adapter to convert the speaker output to hi-level line output.
Potential problem here is that Bose requires a hi-level line input, preferably in the order of 6 Volts....

the yellow mini-iso connector contains the trigger wire for the Bose amp. +12 switches amp on, zero volts (not connected) switches off.
Thanks for answer.

I know that. The problem is some people say I need this for bose adaptation (https://www.amazon.it/INTERFACCIA-SISTEMA-ORIGINALE-PHONOCAR-MERCEDES/dp/B00871JI0W/ref=sr_1_1?__mk_it_IT=ÅMÅŽÕÑ&keywords=Phonocar+04131&qid=1568319011&sr=8-1)

and some others say I dont need I just need to use alpine pre amplified (pre out) outputs. I am trying to understand which one is correct.
 

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Thanks for answer.

I know that. The problem is some people say I need this for bose adaptation (https://www.amazon.it/INTERFACCIA-SISTEMA-ORIGINALE-PHONOCAR-MERCEDES/dp/B00871JI0W/ref=sr_1_1?__mk_it_IT=ÅMÅŽÕÑ&keywords=Phonocar+04131&qid=1568319011&sr=8-1)

and some others say I dont need I just need to use alpine pre amplified (pre out) outputs. I am trying to understand which one is correct.
In theory you should use the pre-outs as they're better quality, however, only if they supply at least 4 Volts (i.e. hi-level)
Even this is the minimum, meaning you will have to turn the volume up quite high. Actually 6 Volt pre-outs would be ideal, but I don't know of any HU that supply this. 2 Volts is definately too low.

So, in summary, if your radio only has 2 Volt pre-outs, you will need an adapter to convert the speaker outputs to line-outputs, if 4 Volts you can try the line outputs.
 

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In theory you should use the pre-outs as they're better quality, however, only if they supply at least 4 Volts (i.e. hi-level)
Even this is the minimum, meaning you will have to turn the volume up quite high. Actually 6 Volt pre-outs would be ideal, but I don't know of any HU that supply this. 2 Volts is definately too low.

So, in summary, if your radio only has 2 Volt pre-outs, you will need an adapter to convert the speaker outputs to line-outputs, if 4 Volts you can try the line outputs.


Power Output: 4 x 50 W High Power Amplifier
Advanced Power IC
Display: 9-inch Capacitive WVGA High Resolution Display
White LED Backlighting System
Control Type: Touch, Drag, Flick
My Favorites Function
Automatic Setting Change for 2 Users
High Grade Audiophile Design
3 PreOuts (4V, Front / Rear / Subwoofer)
AUX-In: 1 A/V AUX Input (3.5mm micro jack)
Steering Wheel Remote Control Function
Vehicle Display Interface Ready (UART connection)

Seems like alpine ilx-f903D is ok as 4V's. Thank you for great info.
 

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Thank you everyone. It was great succes. Sound is great only problem is can adapter was for mito 2014+. (I have 2010) After i change it it will be %100 integrated.

WhatsApp Image 2019-12-22 at 18.30.26.jpeg WhatsApp Image 2019-12-22 at 18.30.27.jpeg
 

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I had the same issue with my Mito 955 (Bose). using the RCA Pre-output to connect the iso cable solved the problem of static noise but the maximum volume output was reduced by 50%. I could not live with that and I tried a different head unit; a Pioneer SPHDA250DAB instead of a JVC KWM745DBT and that reduced the static noise significantly so I returned the JVC head unit. (I did not use the RCA Pre-output)

I can still hear the static noise, but only when the engine is off. The high frequency sounds seem to be abit over saturated and changing the built in equaliser settings doesnt solve this. Even though the sound quality is much better than the orginal head unit I am wondering if not using the RCA Pre-output could damage the system?
 
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