Completed my install this weekend - PeachParts Mercedes-Benz Forum

Strider · #1 06-07-2004, 08:15 AM

OK, lots of work over the last week and this weekend! After I get a chance I'll post some pictures, but here's a description for now:

Headunit: Blaupunkt Orlando CD72. This is from Blaupunkt's top of the line series; Skyline. It has many, many features, like a metal, motorized flipdown face, all digital radio receiver (not just digital tuning, it digitizes the radio signals for sound processing), adjustable display illumination, and includes the automatic volume adjustment for speed like the Becker has. It has two aux inputs, cd changer controls, and an optional microphone input for automatically adjusting the equalizer in the car. Most importantly it has 4 channels of 4 Volt pre-outs, and a sub pre-out. It really is an awesome unit. (Anyone want to buy a perfectly good Becker?)

I currently have a Sony FM modulated 10 disk changer installed that we were using with the stock Becker, but when I get a chance this summer I'll buy a Blaupunkt CD changer

For an amp I'm using the Alpine MRV-450 Five channel amp. I love this amp and the fact that it has everything all in one unit and I don't have to run a separate amp for the sub. Of course I had to run an 8 gage wire from the battery back, and 4 channels of signal wire from the head unit back (the amp can feed input to the subwoofer channel 5 from either the four channels, or just the rear two channels, which gives you some control over the sub channel level from the headunit, so I decided not to run a 5th signal cable back. I had to remove all the seats, and some carpet to run the cables in the stock plastic cable trays. This wasn't hard at all, but a little time consuming. The driver and passenger seat come out with 5 bolts removed and some wires to the power seats unplugged. The rear seat comes out much easier than that.

The speakers are currently some Pioneer speakers that I fit into the stock speaker frames (see post on cheap speaker solution). They sound decent enough. I am still using the stock subwoofers mounted in the front doors, but with the highpass filter turned on for the front channels, and the crossover point set higher, the door speakers are acting more like mid-fills than subs. When I get some more time I'll take off the door panels and investigate those speakers, but I believe they have passive crossovers installed to make them subs. They sound much better when fed from the highpass filter on the amplifier.

The sub, the sub....that was what took the most time, but definately worth it! I installed a 10" Infinity Kappa Perfect 10.1 on the rear parcel shelf in a free air configuration. This sub can be used free-air to half its rated RMS of 350 Watts. The Alpine amp puts out 200 W RMS on the sub channel, so it'll be just fine if I don't play it too loud and hard for extended periods of time. I may one day build a small box for it, but it sounds really good for now.

Here is the bear of it: I had to remove the rear parcell shelf, which wasn't that hard. My original plan was to try and mount the sub under the first aid cover. After lots of measuring and deep sighing, I realized that it wouldn't easily be done and still have a sealed topmount. This is where it got hard. So what I did was use layers of plywood and wood plank I had laying around my workshop and completely filled in the volume under the first aid cover. This involved lots of measuring, odd angle cuts with my radial arm saw, and some wood glue and a couple of biscuits as Norm Abrams would say. After I had the underside of the first aid kit filled, I then cut a hole through it all to top-mount the sub over the first aid kit. Not satisfied with the look of it, also removed the center rear brake light (I long ago installed a trunk wing that has an integrated LED brake light, and always felt pretty lame still having the brake light housing in the rear window) and reappolstered the entire parcel shelf with carpet.

Installed in the car, with a Stinger metal mesh grill on the sub, it looks fantastic. Not stealth like I hoped, but very nice just the same. Like I said, when I get a chance I'll take some pictures. It could be easily be done stealth under the first aid cover if a pair of free air 8 inch subs were used, but these are pretty spendy speakers compared to the 10 inch sub.

The sound is awesome! I'm sure it will get much better after I spend the money on some higher quality speakers, but for now the Pioneers are doing just fine. The best part about this install is that it takes up very little room in the trunk, which was a priority for me. With the sub top mounted on top of where the first aid cover was, the magnet only hanges down in the trunk about 2 inches, and with the amp mounted vertically on a 1/4 inch board against the tank it takes up very little space and I can pack suitcased against it still

seattleMBowner · #2 06-08-2004, 09:24 PM

Good work Strider. I am trying to put some bass into my 1990 300E and am finding that it's expensive. The doors don't have subwoofers. I don't have the tools to cut through the metal on the rear shelf, and I lack experience in doing projects like that, so I will probably have to go to a pro shop to get it done.

Regarding your subwoofer, what is a "free air configuration"? I am guessing that nothing is behind the speaker except the open trunk area (similar to the 5" speakers in the rear shelf) and it is mounted almost flush with the rear deck, so that the speaker is actually inside the cabin.

Why did you need to fill up all the volume under the first aid kit? It seems that you would just need one solid surface to mount the subwoofer, not necessarily layer upon layer of wood.

Thanks.

FYI, one shop has proposed to me that they build a custom box for a sealed sub that would sit just below a vent where the first aid kit goes. The box would extend down to the floor. This sounds like what you did, except that your speaker is supported by the rear shelf structure, where mine would be supported by the box mounted on the floor.

Strider · #3 06-09-2004, 08:04 PM

I filled in the first aid kit solid for a couple of reasons. One is that the Infinity Kappa is a really heavy speaker, like 15-20 lbs. (guess), and I wanted to have really solid support for it. The other reason was that it was the only way that I could ensure there would be a solid surface sealing the speaker when top mounted, or else the front and rear could have had gaps.

Very few subs are rated for free-air use. Exactly right, there is no enclosure for them except the trunk behind the speaker, which is another important reason for having a really good seal in the cabin. The Kappa could handle twice the RMS power if I were to enclose it, but it is plenty powerful at 175 W RMS directly in the cab. (Believe me, you feel it.)

I use my trunk all the time, packing it with luggage on family road trips, so having an enclosure taking up a bunch of trunk space was really not an option for me, although building a bandpass box like you describe would work very well for getting bass into the cab.

About tools: I cut the metal under the parcell shelf with a pair of tin snips after I drilled half a dozen holes for guidance. That metal is much softer there than people realize. After I cut the bulk out with the snips, I used my Dremel to finish it off, then used a file to deburr it.

I'll post some pictures sometime soon.

Gebhard · #4 06-13-2004, 11:27 AM

Slightly off topic, but I get fantastic bass from a JL 10" built into a custom sealed box in the passenger footwell. Very stealth and excellent up front bass. The downside is passengers over 5' 8" have limited leg room.