[sprocket]

Has anyone replaced their factory installed HK headunit with a non-Alpine unit? I am planning on getting the Sony CDX-M850MP, because I really want MP3 with ID3 support in the display - without a CD changer and definitely without an external MP3 player. Any recommendations or experiences?

[musicman]

Good luck,

I am trying almost a month to replace the BOOST headunit with an Alpine Unit and it seems to be impossible. Perhaps it works with the Soundgate OEM4 interface but this interface is not available in Europe. There is a thread in which a Forum member claims that his carshop (Tweeter in Dallas) succeeded in making the combination work. I have however contacted this shop with the question how they have done it, but have not received any answers from them. Based on my experiences, it cannot be done.

The problem is that the HK-amplifier does not recognize the aftermarket headunits. I have used an interface similar to the Soundgate interface but to no avail, the amplifier remained switched off. I am afraid that I have to replace the entire system (speakers and amp) or that I have to use an auxillery interface in order to connect the aftermarket unit to the Boost unit, which will be connected to the HK system. Two radio's in the car, what a luxury.

If you should succeed in combining an aftermarket headunit with the HK-system, please let me know how you have done it.

[sprocket]

Humm... The factory headunit is made by Alpine, as far as I know. I really don't understand why it shouldn't be possible? In the worst case I'd just get a new amp or get a headunit with integrated amp. I am not an audiophile, but I want decent sound and mp3 support.

[laz]

i am thinking the HK system is pretty good ... not bad for a system without a sub ...

[minhi]

Quote:

Originally posted by sprocket
Humm... The factory headunit is made by Alpine, as far as I know. I really don't understand why it shouldn't be possible? In the worst case I'd just get a new amp or get a headunit with integrated amp. I am not an audiophile, but I want decent sound and mp3 support.

from what i've read the hk headunit talks to the hk amp and the hk amp talks to the speakers. i don't think you'll be able to use the hk amp with an aftermarket head. but if you put in an aftermarket head, then you should be able to tap into the speaker leads at the hk amp and run them to your new headunit.

this is rampant speculation on my part, i have not dissected an HK car, but some ideas for you to try...

[sprocket]

Ok, I might not be the brightest when it come to car audio, but doesn't an amplifier just boost the incoming signal and eventually distribute the signal to the speakers via a frequency bridge or the DSP? So, why shouldn't someone be able to hook up a different headunit at the amp? It's still 'just' an amp. I guess in the worst case you'll loose your the HK DSP. Most aftermarket units have pre-amp outputs anyway. Or am I missing something?

[snoopy]

All is not that simple. The audio comes into the amp as analogue then converted to digital then the dsp adds the effect or shapes the music then the shaped digital audio is converted back to analogue then finally it is amplified before going to the speakers.

Now MINI could have made the amp to bypass some parts inside the amp when it does not detect a MINI head unit. But other user comments point to this not being the case.

[sprocket]

Do I get this right? The DSP is in the amp? The audio comes digital from CD/MP3, gets analogue to the amp, digitized again through the DSP and then analogue to the speakers? I would say that that's a bit redudant, isn't it.

Most of the modern headunits have their own DSP and built-in amps anyway and have 3 or more stereo outs for the speakers. As I said I am not much of an audiophile. I am more than happy with a few watts, a simple DSP and MP3 support for a decent sound. Additionally, I have read that the HK DSP shouldn't be that great anyway.

Oh and I don't understand why anyone would want to hook up an external MP3 player that costs more than a 10-disc MP3 changer, just for the 'convienience' of having it dangeling across the dash with an external remote?

Anyway, I would be more than upset to pay $500 for a unit that I cannot upgrade, esp. if it doesn't have MP3 support and no ID tags. Basically I am paying $500 just for the speakers. Ugh.

[snoopy]

yep the DSP is in the amp, (I think to make the headunit cheaper) You are also right on the D/A and A/D bit. On BMW systems the CD changer has a digital out that is plug in to the DSP amp.

To upgrade a H/K system will be very hard, as each part of the H/K reley on other parts of the H/K.

[sprocket]

Well, then I think that I will just have to get rid of the headunit and amp, at least i have nice $500-speakers. Or maybe I will just go for an Alpine MP3 changer?

I really hate when companies make their products non-compatible to other products. Anyway, I will talk to someone at my local Tweeter center to see what can be done. Sprocket's not gonna be here until June anyway. ;-)

[musicman]

I have contacted BMW Belgium and asked them for advice on this matter.

The problem seems to be that the Head-Unit gives a coded "Wake-Up-signal" (the remote) to the HK-amp. This code can not be copied. Since the new Alpine or other aftermarket headunit is incapable of producing this code, the HK-amp remains mute.

The only solution they could think of - and note that they could not guarantee that it would work - is to install both headunits. The original Boost Headunit should be hidden away somewhere in the interior and be connected to the HK-amp, except for the speakerconnections, which should be directly connected to the new aftermarket headunit.

I'm going to try this solution in the coming weeks. As soon as I know something, I will let you all know. All things considered, I would rather replace the crappy HK-system but I am not looking forward to all the work involved.

[snoopy]

Musicman may I suggest you look at seeing if any one will build u a converter box for the system.

Eg they sniff the start code for the amp and the codes for changing the h/k setting. Then program the converter box to turn the amp on at power up and change h/k modes on the press of the non-yet used MFSW button.

Any one willing to give it a go?

[GBMINI]

Musicman,
The HK amp documentation only discusses a simple voltage signal to wake up the amp ... 12V when HU turned on. I think many HUs might be able to do this (eg: signal for auto antenna).
The HK *is* linked via (electronic) Kbus to the HU which must be how the DSP settings are controlled ... maybe the HK requires Kbus communications with HU?

[musicman]

In one of the threads you can find a link to a website in which they give a description on how to add an aux-port to the boost unit.

Also on this website you will find a wire diagram of the Boost headunit. The key outputs there are the number 9 and 10. Nr. 9 is the CAN-/I-bus output. This output is what causes the problems.

Using the auto antenna output does not work. My cardealer has tried it already.

Iancull, where can you find the HK amp documentation?

[sprocket]

Oh great. :-(

Oh well, I will try the HK headunit and amp when I get my Cooper. If I like it, I will just add an MP3 changer. If I don't like it, I will just replace the amp and headunit. I am just cautious, because some people weren't too thrilled with the HP-DSP.

[snoopy]

The amp is controled by the I bus. Don't know about start up it could be done by the head unit and the amp talking on power up or by a simple voltage given to it. By the look of what musicman dealer has told him it think the I bus is more likly.

Changing the DSP modes is done by the I bus. Does any one know if the tone controls are still controled by the head unit or has this fuction also been passed to the DSP in the amp?

[GBMINI]

musicman,
You can go to www.minitis.com and give them some plastic money! You can probably get schematics from your MINI dealership if you are good friends with them.

Pin 15 of the 42 way HK amp is the "radio on" signal which must be + to turn on the amp. Unfortunately I do not know which pin of the stock HU connector it comes from.