RMT200 Tear-Down and Modifications Thread

[BlackSpeed66]

Cool! Hoping to tinker with mine a bit once i get the engine swap sorted out. Still have the GAS crossovers I bought last year sitting on the clothes dryer that I need to install

[bmwman91]

Subbing for awesomeness... you (and the discontinued production) just increased the value of used RMT200's by a factor of 5 I'd guess.

Haha, yeah it is a bummer that this thing went out of production recently. I was hoping that my amp board and mods would have more takers since this is such a good fit for the E30. Anyone know of a VW forum with RMT200 users? I have like $1k worth of amp boards built and collecting dust, so it would be nice to at least break even on those!

[Schnitzer318is]

Haha, yeah it is a bummer that this thing went out of production recently. I was hoping that my amp board and mods would have more takers since this is such a good fit for the E30. Anyone know of a VW forum with RMT200 users? I have like $1k worth of amp boards built and collecting dust, so it would be nice to at least break even on those!

If I can get my hands on one... I'll ship it to you for modification and take one of those boards off your hands. ;) Will PM you if I am successful. Going to be needing a new head unit for my vert install.

[BlackSpeed66]

there's a handful of 'em on ebay.de

Not sure what the shipping policy is.... not too brushed up on my German haha

[Silver Wagon]

Anyone know of a VW forum with RMT200 users? I have like $1k worth of amp boards built and collecting dust, so it would be nice to at least break even on those!

VWVortex.com
been a member there for many years, until i sold my Rabbit. its the go-to site for VW's.

[Schnitzer318is]

What dub did these come in factory? Only place I can find that refers to them by model number is ebay.de and I don't want to front dat shipping. ;)

[AndrewBird]

MK3 Jetta/Golf I believe.

[968Reckless]

Well finally got mine up and running.




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[968Reckless]

I was poking around in my RMT200 today and came up with a couple more mods.

1) USB charging from the rear of the unit. While the rear USB's data pins are not connected internally, the 5V and ground lines are. I mocked up a USB cable connection on there and was able to bring my Galaxy S3 phone from 60% to 76% in ~20 minutes, so it is definitely a high current connection. I have some fresh terminals for the plastic plug housing on order, so I will be able to make proper USB charging cables. This means that a dedicated phone charger can be available that involves NO wires in front of the dash!

2) Rear AUX input. I'll need to wait until the terminals and a 4-wire 3.5mm audio cable arrive to test this, but I am 95% sure that the rear AUX input is fully functional. Again, this would allow for an AUX input to be stashed in the glove box, so that eliminates another cable in the cockpit which keeps things looking nice.

If people that are interested in some of these mods want these, it will be $25 each, or $45 for both. Anyway, I do need to make sure that the rear AUX input actually works though lol. It'll be a week until I know since I am waiting for parts.

Glad to hear 😆


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[bmwman91]

I "finalized" the mods today. The USB charging cable was re-done with a better one with heavier gauge wires, and I built a NICE AUX2 input cable from Canare stage-grade shielded audio cable and one of their beefy 3.5mm plugs. I was also able to find the right terminals that crimp onto the wires and insert into the plastic plug housings, so everything is done up as closely to OEM as possible.

[Schnitzer318is]

That... is... awesome... Respect.

[bmwman91]

OK, so I FINALLY got mine installed. The big delay was mostly due to me combining the installation with a crack-free dash swap, and ordering all of the various HVAC gaskets and other special-order odds and ends that you find when removing the dash. Here's the old dash...it was getting a little ugly.



Initially there were some serious issues with alternator whine and ignition noise.

I ended up building a custom radio power harness so that the RMT-200 would be grounded on the big chassis lug in the trunk next to the battery (where my crossover and amp are grounded), and the constant 12V power for the RMT-200 also comes from the battery's positive terminal (with a 5A fuse about 8" from the terminal). That helped reduce the alternator whine a lot, but it was still audible and not acceptable to me. The harness was constructed from red & black 14ga stranded wire, tightly twisted with a drill and then fed into a heavy vinyl sheath for extra protection against damage. I ran it behind the HVAC controls and then down the center console/under the tranny tunnel carpet, under the rear seat and then up the rear bulkhead with the bundle of factory harnesses on the driver's side.

After consulting our resident expert, Luke, via PM he reminded me that my crossover (Audiocontrol 6XS) has an internal jumper for different ground isolation settings. So I popped it open and changed the jumper from "Ground" to "Isolated". Voila! No more bad noises, whatsoever! Maybe my custom power harness is not needed after all, but it sounds like the stock E30 radio power & ground connections aren't all that great so maybe I will leave it.

Here's how the deck looks in the car. It took a lot of trimming and test-fitting to get it flush in the HVAC panel!











Also, to properly support the back end you will need to make a spacer for the metal bracket in the rear. The main part of it is 9.5mm thick, and then the little extra piece is 1mm thick. This will ensure that the the RMT-200 is properly supported so that it does not put torsional stress on the parts of the HVAC panel that you need to glue additional material to, and so that the bottom of the radio doesn't stick out of the panel. You need the little extra 1mm piece because of how the RMT-200's bottom cover sheet metal is stamped.





I am working on acquiring another clean HVAC panel since I banged this one up a bit while modifying it. The defects are minor and I am probably the only one that will notice, but I still want to do a better one. When I do get the spare, I will document the modifications in here so that others can do the same if they want.

[Schnitzer318is]

Again. Respect.

My only suggestion (and I've done this on radios in the past) is to put a very small radius on the corners of the face of the radio so it matches the corners of the HVAC bezel around it. Makes a huge difference in appearance. Or it could just be my OCD again... I mentioned it because it sounds like you are likewise afflicted with said OCD. ;)

[AndrewBird]

Again. Respect.

My only suggestion (and I've done this on radios in the past) is to put a very small radius on the corners of the face of the radio so it matches the corners of the HVAC bezel around it. Makes a huge difference in appearance. Or it could just be my OCD again... I mentioned it because it sounds like you are likewise afflicted with said OCD. ;)

I thought the exact same thing. Black is slightly off as well, but I suspect it is better in person than it is on camera.

Looks great!

[bmwman91]

Yeah the more glossy finish is not as good of a match as the original E30 head unit, or the CD43 (which was not a perfect match either). But, I honestly do not notice at all. The orange backlight swap that I did to it also makes it blend in very nicely.

So I am now having another sound quality issue. When I switched my Audiocontrol 6XS ground setting to "Isolated" it seems to have killed the bass response in the system. This seems to be sort of a common thing. There is one setting left to try...200 Ohm ground link. My fingers are crossed that this will eliminate the alternator whine AND leave the nice flat frequency response that I want.

One other thing that I am wondering about with repsect to the noise is whether some of it is coming in from the switched 12V line. My assumption is that the switched 12V line just serves as a "turn on" signal, and the constant 12V line is what is actually powering stuff, so I am a little doubtful that the noise is coming from there.