Thread: vw mk4 monson amp and another amp

Thank you guys for all your info on this...I'm very excited to finally start this project now that so many are reporting success!!

I'm a bit confused on the wire hanrnes you used. I'd like to do this without taping into existing wiring. I'm ditching my HU, so I though I would just buy a replacement for the "input" harness at the monsoon. That is, I want a duplicate of the plug that goes into the monsoon from the HU, that way I don't have to tap or cut existing wires. Any idea where I can find one? (Or, a series of aftermarket harnesses I can buy that will do the same thing?)

After thinking about this, I realized I could buy an aftermarket HU harness and connect it to the HU end of this moonsoon input wire, but then I'd have to run my audio out from the PC all the way from the hatch to the dash. Seems lame when the PC is right next to the monsoon.

Originally Posted by kbyrd

I'm a bit confused on the wire hanrnes you used. I'd like to do this without taping into existing wiring. I'm ditching my HU, so I though I would just buy a replacement for the "input" harness at the monsoon. That is, I want a duplicate of the plug that goes into the monsoon from the HU, that way I don't have to tap or cut existing wires. Any idea where I can find one? (Or, a series of aftermarket harnesses I can buy that will do the same thing?)

After thinking about this, I realized I could buy an aftermarket HU harness and connect it to the HU end of this moonsoon input wire, but then I'd have to run my audio out from the PC all the way from the hatch to the dash. Seems lame when the PC is right next to the monsoon.

Make your own harness. Your dealer can hook you up with the terminals and connector. Don't repeat my mistake, though - use shielded wire for your audio out and make sure the shield is grounded but is does not share the audio ground/common.

Originally Posted by R32 JUhl

Make your own harness. Your dealer can hook you up with the terminals and connector.

Cool, I'll start asking around here.

Originally Posted by R32 JUhl

Don't repeat my mistake, though - use shielded wire for your audio out and make sure the shield is grounded but is does not share the audio ground/common.p

What do you mean by "shielded wire for audio out"? I was going to just use speaker wire like I would use for wiring up a home theater system. It's just standed 18ga (or something). Where to I get this stuff and where/how do I ground it?

He means for wires carrying the audio signal from the soundcard to the amp you should use wire like they use in RCA cables. This is because the signal is relatively low voltage and interference can easily distort the audio signal.

There are core wires (say white and red) and they are wrapped usually with strands of wire or a metal jacket that are the ground. The wires form a shield around the core wires that helps block interference.



You can buy shielded audio speaker wire pretty commonly. It should say so right on the package.

I don't think you need shielded wire for the output of the amp to the speakers. Those are relatively high power.

Originally Posted by Bugbyte

I don't think you need shielded wire for the output of the amp to the speakers. Those are relatively high power.

Great, one more thing to buy. Well, better I found out from the forum then bang my head against the wall trying to solve some noise problem myself. At least it'll be a short run, the pc and the monsoon amp both in the hatch. Do I need to ground this like you do stuff that connects to the car's battery? (Short, large wire, unpainted metal on the car) Or, can I somehow connect it to a ground near the PC (my power supply?). Or, maybe the negative wire my power supply takes as input? I understand I can't connect this ground to the audio signal '-' wires.

Thanks Bugbyte!

[QUOTE=kbyrd]Great, one more thing to buy. Well, better I found out from the forum then bang my head against the wall trying to solve some noise problem myself. Kbyrd, my understanding of electronics says you want to use the same ground

Yeah - like I have been!

Originally Posted by kbyrd

Do I need to ground this like you do stuff that connects to the car's battery? (Short, large wire, unpainted metal on the car) Or, can I somehow connect it to a ground near the PC (my power supply?). Or, maybe the negative wire my power supply takes as input? I understand I can't connect this ground to the audio signal '-' wires.

Kbyrd, my understanding of electronics says you want to use the same ground as your carputer to eliminate a ground loop. So whereever you ground your power supply, also ground your shield wire - then again it may not matter where's it's grounded as long as it is dispersing its energy to ground, but I'm taking the "better safe than sorry approach".

I just ran across this thread on vwvortex:
http://forums.vwvortex.com/zerothread?id=2122749

Assuming the posted knows his stuff (I'm not in a position to tell), it looks like the monsoon amp expects a BTL load swinging around 6V on all inputs 4 inputs. Also, there's this talk of BTL a single input being out of phase on + and -. Do the diagrams here or in R32 JUhl's post do this? Clearly they work people have heard pretty good sound coming out out their speakers, but are they correct?

I'm wondering if we can find a pre-packages part that converts either speaker level or line level output from a soundcard into this BTL signal. Somthing like this:
http://store.qkits.com/moreinfo.cfm/fk608
maybe?

The little bit of searching I did didn't turn up any pre-packaged car audio amps that had BTL output

Originally Posted by kbyrd

The little bit of searching I did didn't turn up any pre-packaged car audio amps that had BTL output

I've learned a tiny bit more about car audio amps, and it appears many/some are bridgeable. A two channel amp would have a signal on the left + and the right - terminals. I seems like using two low powered bridgeable amps (feed one channel of the output from soundcard into each) would be exactly what the monsoon amp expects. Someone please chime in on how this differs from the circuit from this thread or R32_JUhl's install thread.