# Monsoon reverse-engineering



## vwgtirob (Aug 16, 2001)

I plan on getting a new GTI early 2002. There are a lot of people asking about hooking up subs and other stuff to their factory Monsoon system. I will definately get the Monsoon system on my car so I can take it apart







. Of course, the system on the NB is different. 
If anyone wants to help me by lending me stuff from their Monsoon system they aren't using anymore (mostly the black box from the trunk), I'll reverse-engineer it to give everyone any answer anyone wants about it







(eq info, crossover slopes, amps present, etc.)
Or I can wait until the 24V VR6 GTI comes out to play with my own...


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## ghillis (Jul 7, 2001)

*Re: Monsoon reverse-engineering (vwgtirob)*

I just bought a Monsoon HU and amp to do the same thing. My A/D card crapped out on me, but it will be back soon, so I can make some measurements. That plus a VAG-COM will hopefully allow me to do some figuring out a bit about the sucker. I would be interested in consulting with you on the project. There is so much conjecture and misinformation about the thing that needs to be put to rest. Speaking of which, what is your source of the NB system being different? Are you referring only to the HU?


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## MADBUG (Dec 14, 2000)

*Re: Monsoon reverse-engineering (ghillis)*

Speaker placement is different for Monsoon Bugs.Also from what I understand,the Monsoon 'amp' has fixed Eq.So the Eq adjustment will be different for each car.
I beleive that they do have Eq programmed in there.I RTA'd a Monsoon Jetta,and the response is almost completely smooth.


[Modified by MADBUG, 10:39 PM 9-24-2001]


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## vwgtirob (Aug 16, 2001)

*Re: Monsoon reverse-engineering (MADBUG)*

I know that there are vehicle-specific equalizations (like in the Mikro Audio system), and a different speaker configuration in the New Beetle.


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## vwgtirob (Aug 16, 2001)

*Re: Monsoon reverse-engineering (vwgtirob)*

I have access to an Audio Precision System II Cascade







If you don't know what that is, see http://www.audioprecision.com/







I've also got a scope, low-distortion signal generator, and a audio-frequency (DC-100kHz) spectrum analyser adapter for the scope, plus a high-precision DAC/ADC for the PC.


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## MADBUG (Dec 14, 2000)

*Re: Monsoon reverse-engineering (vwgtirob)*

I'm employed as an ET,and you got more equipment then my employer!!


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## vwgtirob (Aug 16, 2001)

*Re: Monsoon reverse-engineering (MADBUG)*

I don't have an AP, I just know someone that has one







The other stuff is mostly home-built. I like to design amps in my spare time.


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## ghillis (Jul 7, 2001)

*Re: Monsoon reverse-engineering (MADBUG)*

The Passat and Golf amplifiers are indistinguishable internally other than the tags which indicate the car model. There aren't that many components, and I know what most do (in the limited way a mechanical engineer understands electrical engineering things). There are no programmable ICs in the amp, and I have been unable to find any differences thus far. There are obviously a ton of surface mount resistors and capacitors which could have different values and be used to adjust the output characteristics of the op amps, but I don't think that could achieve the 103 poles that Monsoon claims. I believe that the equalization is in the head unit (TSB 91 99-09) using a DSP, and the crossover and amplifier is all that happens in the amplifier. I will connect a DAQ and run some frequency analyses in a couple weeks when my in-dash CD Changer (test CD is a must) arrives, looking at both the HU and amp outputs.
I have looked at the insides of the HU and amplifier that I bought recently (not the one in my car) I was rather surprised that the amp does not have a power supply. The power ratings for the thing cannot be RMS. 12 V p-p = 8.5 V rms into 4 ohms is only 18 Watts, into 2 ohms is 36 Watts. I realize that the woofer and tweeter power could be added together, but they operate at different frequencies, I think they are not additive since each is a half channel. Ok, you guys how many volts is available in the power supply of a typical 180 Watt car amplifier?
As for slopes, there are 12 quad op amps in the amplifier, I assume that several are used as active cutoff filters at the high and low ends. That would still leave enough for a 4 pole (12 dB/octave if memory serves) crossover. Again, I am not an audio guy, what is a typical active crossover slope? 
I've traced the wiring in the car and hope to get the information on my homepage eventually. This weekend I hope to get a chance to see which of the plugs terminals are actually connected inside the HU and see which VDA connections Mute, Tel, Line level out, etc. might be functional.
I found out a couple of other interesting things so far, there is a switch in the HU that senses when it is removed from the dash. I think that when the switch is tripped and the voltage removed, SAFE mode is invoked, but either by itself won't necessarily put it in SAFE mode. The HU circuit boards have the same numbering characterisics as the amp and both have Delco Amp ICs, I am sure that the HU is built by GM/Delphi/Monsoon just as the amp presumably is.
Can either of you, or anyone else out there find a data sheet on a Delco 82452 Amplifier IC? There are 8 in the Amp.
When I am done with the units, I would be happy to lend them to you, vwgtirob so that we can have independent validation of results. Sorry for the ramble. IM me.


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## vwgtirob (Aug 16, 2001)

*Re: Monsoon reverse-engineering (ghillis)*

The HU is just a modified Panasonic/Clarion HU. The black box in the trunk is designed by Monsoon and manufacturerd by Delco (which also manufactures the Rockford Fosgate HU's, BTW).


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## theguero (Aug 10, 2001)

*Re: Monsoon reverse-engineering (ghillis)*

quote:[HR][/HR]Can either of you, or anyone else out there find a data sheet on a Delco 82452 Amplifier IC? There are 8 in the Amp.[HR][/HR]​I have some buddies that work at Hughes Electronics. I will see what I can do.


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## ghillis (Jul 7, 2001)

*Re: Monsoon reverse-engineering (vwgtirob)*

quote:[HR][/HR]The HU is just a modified Panasonic/Clarion HU. The black box in the trunk is designed by Monsoon and manufacturerd by Delco (which also manufactures the Rockford Fosgate HU's, BTW).[HR][/HR]​I keep seeing that claim, but never anything to back it up. The circuit boards in the HU and amp are clearly from the same manufacturer. The etched symbol markings, QC stickers, part numbering and their layout lines are the same, the heat sink mounting is identical ,the cases snap together the same way and they both use Delco power amplifiers. There is no question in my mind that if the amp is made by General Motors/Delco/Delphi, then so is the HU, and in the same plant. 
Thanks theguero, could you have them look up Delco 96405 and 23136 as well, these are the ones in the HU.


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## theguero (Aug 10, 2001)

*Re: Monsoon reverse-engineering (ghillis)*

Just to keep you updated. My friend turned up nothing with that part number. I emailed Delphi and got a response WITH the same response. The person at Delphi said that those might be date codes vs. part numbers. So they ask me to provide more info if I had it. So I told him where the part numbers came from. I am now awaiting a second response. Keep your fingers crossed that I get a positive response. Generally GM does not let info out like that until 3 years after they stop producing the unit.


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## theguero (Aug 10, 2001)

*Re: Monsoon reverse-engineering (ghillis)*

After extensive communcation with Delphi the final answer is they WON'T disclose this info to me. It has to be 3 years after production is stopped on it before it is given out to the public. So I guess we are on our own.







http://****************.com/smile/emthdown.gif


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## Concept (Aug 24, 2001)

*Re: Monsoon reverse-engineering (theguero)*

Wow, you guys are just amazing. (That's my non-value-add comment to this thread.)


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## Dave 53105 (Oct 2, 2001)

*Re: Monsoon reverse-engineering (Concept)*

Regarding the P/N's you are seeking info on, there is a prefix missing from the numbers. If you have contacts inside Delphi Delco electronics ask them to pull the prints for 16082452, 09396405, 16223136 and you'll probably get the info you're looking for.


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## ytsejam (Oct 31, 2001)

I would really be interested to find out what you guys come up with. I am curious about what is being done in the HU and what is done in the AMP.
The Monsoon site talks about equalization specific to the vehicle and also circuitry designed to protect the speakers. Does this mean that it limits frequency response and volume output to the individual drivers (i.e. tweeters)? Or is it just a marketing shpeal? I am actually hoiping that DSP is being done in the HU that way when I replace it with my Pioneer Premier HU I can just worry about the AMP.
So on the AMP, it does the crossover right? I'd like to to do get rid of the rear tweeters and reconfigure those two channels to drive more bass speakers with a subwoofer style crossover point. I plan to replace the fronts with custom components, replace the rear woofers with a good bass drivers. I could add two more bass drivers to the rear deck or possibly in a box using the channels previously used for the tweeters. If the crossover can't be changed or if those channels are lower powered (doubt it since supposedly the rear tweeters are 2-ohm), maybe I'll just disconnect that channel altogether and possibly add a separate amp.
I haven't started the upgrade yet, so I haven't taken a good look at what's in there for myself yet. Good luck. Looking forward to any more info you find out.
Ivan


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