Factory stereo

Yeah it was the Boost bit that had me thinking that there was an extra amp but it aint there. I've had all the panels off and buzzed out the speaker wires as check when I put my own speakers in.

I heard elsehwere that the HK set had an external 4 channel amp in the read quater of the boot but I havent seen any pics either

I must admit that the standard unit is reasonable as long as you dont' push it to hard. And I would go as fas as to say is a very good system for a factory fit. Even with the standard speakers which look crap.

I'm looking to install an amp and a sub soon but I don't want to go mad. Looking for nice sound with a hidden fit.

Can anyone tell me what amps they have fitted where without losing any space? EG under the seats, or under the mat in the boot or the rear quarters.

Re: Re: Re: Re: Stereo

snoopy said:

The Boost part is for a upgraded amp INSIDE the head unit. The Boost has a upgraded amp is 4x20 watts and the standard wave radio has a 4x10 watts amp in the head unit.

Click to expand...

Snoopy,


Does this mean there arent balanced outputs? I ordered the DIN plugs today


--
Cheese

Hello,

Simple question if anyone can help?

Need to upgrade from stardard Wave Radio to singel cd?

Factory code £205 for some single cd 4x15 effort as stated in new brochure. Seems quite a lot for such a simple affair, but the salesman tells me it's an Alpine unit, which I don't believe, and where's the security? The salesman told me not to wory as it's really difficult to get out (is this true?), but when has tha ever bothered your petty tea leaf, had a unit crow-barred out of my BMW.
So looking down the dealer fit accesories list see sony units a CDX CA600X for £175 4x50 4ohm, but fitting would have to be on top and apparently it's not a normal DIN socket? Can get this unit from elswhere at £125 so how difficult is it to fit? Does anyone know if I need any special tools? Are the speakers compatible with a 4ohn head unit? Salesman said I'd need to take half the dash out which I loath to do as you never get it back right and then there's always that rattle etc.

Also does it spoil the look?

For once the salesman is right the single slot cd is indeed made by Alpine and it's not to bad, radio lets it down a little though.

The head unit has no embedded security devices or codes. If the crow came out then so would your radio. But there are 2 things in your favour the unit is not a standad DIN size and if the plastics get broke getting it out they are all easy to replace.

To fit an aftermarket head unit you will need an adaptor plate (filler panel) if you want it to look neat. The standard speakers with my single slot are rated at 15W 5ohm so they will work with a standard head unit although with the power you are quoting it won't be long before they pop fortunatly they are easy to replace.

As for getting to the head unit there are threads that tell you how and it is not difficult nor will you get rattles after. So this time your salesman was wrong. 1 all I think.

I would be supprised if there is yet another head unit for the HK system as the standard head unit although looking basic potetaily seems very flexiable. I managed to get the pinout from Alpine for the single slot CD an there are no low level outputs mentioned, loads of inputs though, Sat Nav, TV, phone, Aux. Unfortunately they get selected by special codes sent to the unit via the CAN bus. Haven't got any info on these codes yet. Might be nice if I could activate all these inputs for my phone & MP3 player etc. I'm looking at this.

I'm hoping to get the unit powered up outside of the car so I can see if there are line outs to drive an external amp cos I want to amp up the fronts and run a sub. I lothe using high level speaker converters.

Well probing my head unit this evening has proved that the unit does have some kind of security even though I thought it did not. I was trying to find if the unit has line outs and tried powering it up on the bench but it just came up with the message "-DIASBLE-" on the display. Further checking in the car revealed that Pin 9 (CAN+/I-Bus) responds with a coded message when the radio is powered up that enables the radio. I'm not sure if this code is unique to my mini or to all mini's. I suspect the first.

I have attached the pinout info that I have learned so far. Let me know if you get anywhere with it?

Still no luck finding thoese line outs yet as its got dark now. I know there are amps out there that accept speaker inputs but it is an additional conversion process that mushes the signal.

Just checking the pinout shows that this head unit has a lot more to give. Just have to figure out to activate it all.

Re: Re: Re: Re: Re: Stereo

noahe said:

Aw, crap... Well that would be different info than my dealer told me, or what I've read here.

So... If the BOOST amp is internal, and inside the head-unit, does the radio provide seperate outputs as a balanced differential signal, or does the H/K and SoundModule systems get yet another single slot CD head unit, that looks the same as the 4x10, 4x20 units, but outputs just a signal level?

Click to expand...

Balance differential signal And factory amps

Well a balance system uses two signal lines i.e. the + signal line and the – signal line. In an unbalanced system or in a single ended system you have only one signal line. The other half or reference is a ground point.

With balanced feed systems they have a far greater noise immunity that the unbalanced or single end systems. The reason for this is in the balance system any noise that is pick up on the feed lines is normally the same level in both wires. When the signal gets to the amp it is very easy to remove this noise, as it is the same on both signal wires.

In a balanced system the signal is normally the opposite on each wire. I.e. max positive on one wire and max negative on the other wire. So what the amp is doing is amplifying the difference between the two signals. Since the noise is the same on the two signal wires it in not amplified.

Most balanced systems use this difference theory, although they do not have to. But it is easier and cheaper to do so.

Now the boost Head unit has an upgraded amp module inside the head unit. The iceman has hinted on this before. To get these hight power levels from the head unit they would be using an audio amp family called BTL.

BTL is bridge tied load. This is when two amps are used in the final audio stage. One set of amps (i.e. the speaker + lead is the output of this set of amps) is driving its output up. The other set of amps (i.e. the speaker – lead is the output of the other set of amps) is driving its output down.
This means the load between speaker + and speaker – leads are see twice the voltage and 4 times the power compared to a single ended amp.

This is why you must never connect any of the speaker leads to ground or each other. As you might let out the magic smoke.

As you can now see that a BTL output provides the same signal to one output and an inverted signal to the other. This sounds like all we needed for a balanced feed, two signal wires and opposite signal on each.

So the input to the H/K amp and the Sound Modul amp is the speaker wires. On looking at the H/K system used in the E46 this is true. The H/K amp in the E46 just takes the 4 speaker outputs( 8 wires) and using them as the input to the amp.

I am guessing the wave head unit also use a BTL output, as it can be speced with the Sound Modul amp.


So the wrap up of this is the following guesses I have made about the system.

The H/K amp and sound Modul use the BTL output (speaker output) of the head unit as the input source.

The Boost head unit for the H/K option is the same unit used for normally Boost systems. Although the head unit must be told that is has a H/K amp so it can make some changes to its operation. Like not to use the speed related volume in the head unit as the H/K amp now does this, and to add the sound effects to the list of options on one of the buttons.

Remember these are guess about the H/K systems as no one has seen one. But they are educated guesses and if any one thinks one or all is wrong. Please correct me. As once we get to the bottom of it a FAQ can be done and everybody questions will be answered.