[yusufm786]

Hi Guys

As the thread title states, I am planning to do an ASD retrofit on my 2012/09 euro build 335i with HK audio.

Information on this seems to be quite dispersed on the net and battling to find answers to my specific questions.

So some background from ISTA: In cars with the Top-Hifi audio system (Harmon Kardon), sound is sent from the head unit to the HK amplifier via the MOST bus (fibre optic). The HK amp then converts the digital signal to analogue and sends the audio signals to the various speakers in the car. The MOST bus also tells the HK amp when to switch on or off, as it needs to be on only when the head unit is sending audio to the amp.

In cars with ASD, the ASD module is connected to the KCAN2 bus which gives it speed signals, load readings, and other signals in order for it to be able to generate the correct car engine sound at the output.

If the car does not have HK, then the speaker wires which come from the head unit are then passed through the ASD module, which then adds its engine sound signal to it, and then outputs it to the speakers, i.e. the ASD module sits in series with the head unit and speakers. Therefore, if you do a ASD retrofit on a car like this, you physically have to cut wires/wire it such that the signal from the head unit to the speakers is broken, sent through the ASD module, and then sent to the speakers.

In a car with HK, the ASD module outputs engine sound signals similar to the above, however, these signals are input to the HK amp and the HK amp becomes responsible to perform the addition of the ASD engine sound signal and the audio signals. Since the speaker wires are only run from the HK amp to the speakers, there is no longer a need to cut these wires because the ASD module does not sit in series with the head unit, the HK amp and the speakers. Therefore, in theory, the retrofit of an ASD module to a car should be easier if it has HK audio.

So far I have got the following wiring diagram and pinout from ISTA/D based on a newer car with ASD and HK audio.





As you can see, there are 9 wires from the ASD module to the HK amp - four sets of speaker signals, plus one radio signal ON signal (to tell the HK amp to switch on in the case of the car being on but the actual audio system is off)

These 9 wires go to connector A52*3B on the HK amp.




The problem I am having, is that my connector and pinout on my HK amp does not have so many inputs (as per the drawings on ISTA), and I cannot seem to find a pinout for my particular connector. My one looks like the pictures below.





Does anyone have a pinout for the connector - alternatively if they have done this retrofit if they can put me in the correct direction?

[DayvG]

Hello buddy, I have the same HK amp with the same MOST plug. Did you have any joy with this retrofit? I read somewhere else there is a different HK amp for ASD with I different MOST pinout for the ASD.

[yusufm786]

Originally Posted by DayvG

Hello buddy, I have the same HK amp with the same MOST plug. Did you have any joy with this retrofit? I read somewhere else there is a different HK amp for ASD with I different MOST pinout for the ASD.

Hey man

Yes I did in fact get this to work, but it wasn’t entirely straightforward. It is correct that HK amps for ASD are different, and our HK amps don’t support ASD.

So what I did was create my own wiring harness, which takes the output of the HK amp (to the speakers), and then inputs those into the inputs of the ASD module, and coded the ASD module to work in stereo mode (Ie as if there was no HK amp in the car)

[Gabrola]

Originally Posted by yusufm786

Hey man

Yes I did in fact get this to work, but it wasn’t entirely straightforward. It is correct that HK amps for ASD are different, and our HK amps don’t support ASD.

So what I did was create my own wiring harness, which takes the output of the HK amp (to the speakers), and then inputs those into the inputs of the ASD module, and coded the ASD module to work in stereo mode (Ie as if there was no HK amp in the car)

You better undo this real quick.

You are sending speaker-level outputs to the the ASD module when it is expecting line-level outputs/inputs - be ready for your ASD module and/or HK amp to burn at any moment. The ASD acts as an amp in cars with the base stereo system which is what you have coded it to do. So you are essentially amplifying an already amplified signal. Your audio will probably sound like shit and clip like hell at medium to high volumes. You've also messed with the entire sound stage by having four channels driven by the ASD module and the rest by the HK amp with no tuning capability at all.

Only proper way to do this retrofit is to replace your HK amp with an ASD version one.

[IK6SPEED]

ASD deserves to be burnt up anyway.

[yusufm786]

Originally Posted by Gabrola

You better undo this real quick.

You are sending speaker-level outputs to the the ASD module when it is expecting line-level outputs/inputs - be ready for your ASD module and/or HK amp to burn at any moment. The ASD acts as an amp in cars with the base stereo system which is what you have coded it to do. So you are essentially amplifying an already amplified signal. Your audio will probably sound like shit and clip like hell at medium to high volumes. You've also messed with the entire sound stage by having four channels driven by the ASD module and the rest by the HK amp with no tuning capability at all.

Only proper way to do this retrofit is to replace your HK amp with an ASD version one.

In cars with stereo sound, the ASD amp is installed after the head unit, i.e. it get's speaker level inputs not line level inputs. By installing it after my HK amp and coding it to work as stereo, it's basically mimicking the stereo installation, thus there should be no risk. Audio does not clip at all and it is as clear as it comes.

With regards to four channels driven by ASD, and the remainder not driven by ASD, sure, that is true but not relevant. You don't need ASD coming out from more than four speakers. Once again, in a stereo installation this is the way it is in fact set up.

With regards to tuning capability, the HK amp still runs all speakers, so it can be adjusted as it could always be - no change there.

[DayvG]

Originally Posted by yusufm786

Hey man

Yes I did in fact get this to work, but it wasn’t entirely straightforward. It is correct that HK amps for ASD are different, and our HK amps don’t support ASD.

So what I did was create my own wiring harness, which takes the output of the HK amp (to the speakers), and then inputs those into the inputs of the ASD module, and coded the ASD module to work in stereo mode (Ie as if there was no HK amp in the car)

I don’t suppos you can give me some pictures etc of the retrofit? I’m about to buy an ASD UNIT and I’m more than happy to get amongst this. Pinouts and the plug you used would be awesome! I coded my mates 435d today and it sounds amazing now! I need it in my 530D. Cheers mate

[DayvG]

So trying to get my head around your configuration. So you take the feed from HK amp to speakers and tap into the ones you want....eg FR FL RR AND RL. That then goes into the ASD module input. The output of ASD then inputs back into the same speaker output thus ADDING the ASD sound? Or am I way off. I’m struggling to get my head around how the ASD gets the “sound” into the speakers.

[yusufm786]

Originally Posted by DayvG

So trying to get my head around your configuration. So you take the feed from HK amp to speakers and tap into the ones you want....eg FR FL RR AND RL. That then goes into the ASD module input. The output of ASD then inputs back into the same speaker output thus ADDING the ASD sound? Or am I way off. I’m struggling to get my head around how the ASD gets the “sound” into the speakers.

In principle yes, but I built my own wiring harness including 3D printing of a connector to allow me to connect into the system without cutting any wires. The harness also has a CAN bus interface which taps into the REM module (also without cutting wires), so it can get the RPM levels and you can access it through Esys. Finally there's a wire tap to tap into power to activate the ASD amp when the radio is on.

I'll post some pics in the next post of the harness - I don't recall if I took installed photos.

If you want to save yourself the time you can buy my full kit and just plug it into your car - I had my fun with it already :-) DM me if you are interested

[yusufm786]

Pics below

[Gabrola]

Originally Posted by yusufm786

In cars with stereo sound, the ASD amp is installed after the head unit, i.e. it get's speaker level inputs not line level inputs. By installing it after my HK amp and coding it to work as stereo, it's basically mimicking the stereo installation, thus there should be no risk. Audio does not clip at all and it is as clear as it comes.

That's not true. The headunit actually drives the speakers in the stereo system with a high line-level output which is is around 7V, whether directly to the speakers or to an ASD module. Only difference between the headunit to speakers or headunit to hifi amp signal is the EQ settings but it will be pushing around 25W/7V per channel either way. The HK amp pushes 50W per channel so you're basically doubling the expect load to the ASD module.

[yusufm786]

Originally Posted by Gabrola

That's not true. The headunit actually drives the speakers in the stereo system with a high line-level output which is is around 7V, whether directly to the speakers or to an ASD module. Only difference between the headunit to speakers or headunit to hifi amp signal is the EQ settings but it will be pushing around 25W/7V per channel either way. The HK amp pushes 50W per channel so you're basically doubling the expect load to the ASD module.

Ok this is true - HK amp definitely sends more power to the speakers than stereo amp.

Been running my ASD system for well over a year now though without issue, so I assume that the ASD module can in fact accept the amplified input. Also, I rarely play sound loudly, so I am far from the maximum output of the HK amp

[MemphisM5]

Originally Posted by yusufm786

Ok this is true - HK amp definitely sends more power to the speakers than stereo amp.

Been running my ASD system for well over a year now though without issue, so I assume that the ASD module can in fact accept the amplified input. Also, I rarely play sound loudly, so I am far from the maximum output of the HK amp

Hi, I'm trying to do the same retrofit as you, so there's HK in my 2012 328i w/o ASD pins. Got ASD module with harness from ebay, but it comes from Hi-Fi audio I believe with only 0.35 diameter wires.
Did you try just to connect ASD outputs directly to HK outputs to have mixed sounds in stereo mode? Also did you run RAD_ON from the HU? and maybe you have complete harness for sale Thanks.

[Encanto]

In the HK(688) OEM amp with ASD the engine sound is mixed with the music in the OEM amp - the ASD only works as an engine sound generator.

Retrofitting the ASD to a non-ASD HK(688) OEM amp requires the engine sound mixing with music after the OEM amp, which requires the ASD to mix the OEM amp audio output with the engine sound instead of only generating engine sound, and expecting that the ASD can withstand 14-35V inputs instead of 10V max.

The ASD is not designed to accept the output of the HK(688).

Good luck with this retrofit.

[MemphisM5]

Originally Posted by Encanto

In the HK(688) OEM amp with ASD the engine sound is mixed with the music in the OEM amp - the ASD only works as an engine sound generator.

Retrofitting the ASD to a non-ASD HK(688) OEM amp requires the engine sound mixing with music after the OEM amp, which requires the ASD to mix the OEM amp audio output with the engine sound instead of only generating engine sound, and expecting that the ASD can withstand 14-35V inputs instead of 10V max.

The ASD is not designed to accept the output of the HK(688).

Good luck with this retrofit.

I believe topic owner yusufm786 has made the same setup with non-ASD HK. Interesting is whether ASD was connected to woofers, which have the most powerful outputs from HK, or just to mid-range speakers.

[MemphisM5]

Some progress with ASD. So I've connected ASD to CAN from COMBOX, coded it with VO and FDL with F80/S55 engine sound and then directly jammed outputs from ASD to outputs from HK! Everything works fine, there's engine sound from speakers, but when big connector is not attached to HK. When I put connector back, even without power supply attached to HK, ASD sound dissapears! Putting HK in work with power and MOST gives radio sound without any issues.
So there's some strange things happening when ASD outputs are in parallel with HK outputs, either in ON or OFF state, even without power attached. Polarity of ASD and HK outputs are correct, taken from TIS. ASD coded as STEREO and SL or TL power level.
Need some advice... Thanks.

PS: Checked with multimeter, HK outputs are "minus" and mosfet (maybe). ASD outputs shows around +6V on both "-" and "+" outputs. So seems when connected to HK, it just conflicts with HK "-".

PPS: Finally made same thing as topic owner. Put HK outputs to ASD inputs (only for two front speakers) and it sounds amazing.

[pjnayler]

@yusufm786 any chance you can make a rough wiring diagram? thank you

[MemphisM5]

Just made some diagrams and photos of my installation. It's here : https://f30.bimmerpost.com/forums/sh...php?p=27945320