Audio Upgrade to my 86 560SL No Humps.

[GSMITH]

After my failed attempt to make the car look good with humps ( see Please Comment Good or Bad idea ) I finally finished this project and I thought I would share it with all of you. I made a custom sealed enclosure to house 2 10" subwoofers. Not enough room for a ported enclosure. On top of that I built seperate boxes for 2 6"x9" MBquartz speakers. See attached pictures. I still have to attach my homemade windscreen. I will add a picture of it later.

A little history that led up to this.
The car had a good Alpine cassette head unit and the 6x9's in the carpeted panel powered by a Alpine V2 50Wx2 amp that was in the trunk bungee corded to a wire rack from an oven and 2 blown 4" speakers in the dash when I got the car and a cheap EQ in the glove box that was bad. Worse yet someone had tried to put Pioneer 6x9's in the rear side panels. They left the mesh covers but it still looked real bad. I replaced the 4" in the dash with 4" dual cone Pioneers removed the EQ and it sounded ok with the hard top on. Once I replaced the bad convertible top and was able to go topless I knew I had to do something else. I started by building a windscreen and filled the gap between it and the rear with some 1/4" sheet plastic I had lying around. To hear it well while on the road I had to turn the volume up to the point that the 6x9's would distort under heavy bass. The staging was all messed up. I had bass-mid from the rear and highs from the front. I lived with this thru the fall until now.

Construction
I removed the old vinyl from the rear panels and reskined them with the best color match I could find from my local fabric store. The plastic panels were really brittle around the holes that were cut for the 6x9's so I used tape to hold it together until I could get the vinyl glued back on. Then I made the sub box out of 3/4" plywood. I made the bottom at about a 10deg angle to get the most room I could and built up from there to about 9" below the convertible cover. I had to leave about 2's from the drivers side so that the handle for the cover could still be operated and I stepped the bottom up over the hump. Lots of odd angles but I beleive I ended up with about 1.25cu ft per sub. I covered the box with poly batting to soften it up a bit before I streched the vinyl over it. You can see in the photo's I had trouble with the drivers side. I may need to sew this up in the future. With the sub box in place I had to figure out the final placement of the Sony amp so that I could size the boxes for the 6x9's.
I built these boxes and attached them to the 1/2" plywood cover that filled the space inside the convertible top cover. Wrapped this up the same as the sub box. Mounted the Alpine amp to the bottom side and made a metal hook to keep it in place that goes from the plywood cover over the lip that the convertible top cover goes down over. I covered the hook with felt so that I would not damage the fabric top. You can see the hook in the picture with the cover open.

Final results.
What I was after was a good full range clean sound. Not a system that you can feel the pounding from a block away.
With the subwoofers I can high pass filter the 6x9's so that they do not distort at twice the level as before and since they point forward I get good mid and highs from the rear. The subwoofers make up for the loss of bass from the front and rear and the staging is just about perfect. I have to set the F/R fader toward the front and balance the 6x9s/Subs with the gain on the amps The stageing is a little above chest high but without tearing up the dash there is little that I can do to raise it without DSP. Maybe if the head unit dies I will fix this.

I know someone will ask the spec's so here is the setup.
Alpine TDA-7554 cassette head unit 15W rms powers the dash speakers.
2 Pioneer 4" dual cones in the dash with bass blocker caps.
Alpine T502 amp 2 x 50W rms powers the
2 MBQuarts 6"x9"
Sony XM2002GTR 2 x 250W rms into 2ohms
2 Kicker Comp VR 05CVR104 10" dual 4 ohm coils in parallel for 2 ohm each.
In total I added about 100lbs to the car.

Why did I keep the cassette head unit?
I use a 4Gb Sandisk mp3 player hooked up through a cassete adapter.
I tried to use a FM transmitter but there are no clear channels in my area and I would have to retune it if I drove more than 5 miles in any direction.
When it dies I will replace it with a unit that has DSP so that I can readjust the staging a little higher and a aux in so that I can get rid of the cassette adapter.

What is playing on this setup?
Most of the time I listen to Jazz but just about everything else execpt County/Western and Rap.
I could never get past the lyrics in Country and there is very little Rap that is clean enough for me.

If I had to do this over again I would make the sub box out of fiberglass to get more cu. ft. So many odd angle cuts made this a real pain to keep it sealed tight.

Almost forgot. What good is a project if you cannot buy a tool? I had to buy a jigsaw to cut the holes for the speakers.

[GSMITH]

Here is how the windscreen turned out. Only $20 in parts.
3/8" Aluminum rod, screen, rubber hose and ground lugs for hinges.

Spent another $20 for a tube bender. Could have borrowed one from a parts store but when I save this much on a project I just can not stop myself from buying another tool.

[Strife]

The windscreen looks really credible! I've wondered how much importance there is in the second windscreen on the OEM model that covers up the "back seat" area, but in your case, this is moot. I might try this myself, although I might shape it as close to possible as the original one (which I have on my other car). For $40 in supplies, it's worth a shot.Where did you get the ground lugs? Do you have a "parts list"?

[GSMITH]

Thanks for the complement. I was a little concerned about sharing this after reading the posting for the $120 screen door model this week. But I thought that my design was a lot closer to the original $400+ model and a lot cheaper for those among us to try and make one.

To answer your question about the second screen just put the upright screen down and drive around at 45 MPH then remove the entire screen and drive around again. You will find that it makes a big difference. After I did the speaker box I drove around without the screen and was comfortable up to about 45 MPH over that speed my baseball cap wanted to come off. Before I had either I was only comfortable to around 35 MPH.
Your mileage may differ.

Since you have a one to copy from I would make a jig to its dimensions to bend around. It would only take some scrap plywood and some screws to make one and would give a much better result then using the tube bender. All the tube bender was good for was to keep the corners rounded. Keeping the corners flat to each other was pretty hard with the tube bender as the first couple of degrees of bend took a lot more then I could get by squeezing the handles. After it started to bend it could be bent further with the handles. I will make a jig the next time. I found the ground lugs and rod at a local ACE hardware. I got the hose at a local Auto supply. Just take the rod in and see what fits. The lugs are made to connect a ground wire to a copper rod that is beat into the ground. These were made out of aluminum and I ground the locking screw to make it sit lower and filed the lug body smooth before I painted them. With your polishing skills you might be able to get them as shiny as your engine compartment. I had this on my car before at a lower level and it worked ok but now since it sits higher it is much better. The screen tended to not stay up under hard acceleration so this time I put a flat spot in the rod for the locking screw to get a better grip. I would have loved to make a the locking screw spring loaded but I do not have the tools to do this.

When this screen wears out I might use a metal screen so that I can spray paint it all flat or gloss black for a better look. The fiberglass screen melts a bit from spray paint and stays gummy and the screens black color fades from the sun unpainted. The rubber hose does not have any problems getting gummy with the paint. It might flake off though. The only other thing you will need is some black weather strip adhesive and some clamps to hold the screen and hose in place till it dries. To get the screen tight is the hard part since the loop is C shaped the opening wants to close when you pull on the screen. Just get it as tight as you can and mount the lugs after you are done. This lets you tighten the screen opening by spreading the lug spacing out when you mount them. I also thought of using chrome hinges from a marine supply house that are made so you can lift off a cabinet door but they were expensive at around $40 and I would have had to drill and tap them for the locking screw.

I almost forgot that you need to fill the hole behind the screen and have something to mount the lugs to. If you have speakers in the rear deck then I would suggest that you make a panel out of 1/2 plywood that fits just below the cover and cut a hole in it so that you have about 2" along the sides and back and about 3-4" across the front. You need to make the front wider because of the stress from the vertical screen. Paint or cover to match the interior and fill the hole with the same screen that you used for the vertical screen. If you leave this deck solid it will kill the mid and highs from the rear speakers. If you do not have speakers in the rear deck just leave it solid. Form hooks from some metal strap to hold it in place just under the cover. I covered my hooks with felt to protect the soft top and paint and hide the ugly metal strap.

I have had the car over 70mph with no problems. I could even light a cig with a cheap butane lighter at that speed. There is a little wind from the back so mine might be a little narrow. Does yours fit inside of the vinyl of the convertible cover??? It was hard to tell from the pictures I could find. I assumed it fit inside so that the cover would clear the screen. I could not tell if they mounted to the cover or under the cover. Since mine does not mount to the cover I had to make it fit inside of it. I might have to come up with a way of mounting it to the cover for the next version.
If I only had access to a welder and a metal lathe.

I do not know how anyone could be happy driving this car at highway speeds with the top down without a windscreen. I felt like I was being sucked out of the car from all of the wind. But with the $400+ price tag I can understand why they would.

Hope that this helps you with your new project.
Please post your results with pictures from both cars for comparison.

[MyCarIsWilhelm]

I found this company called, Rub n' restore. They make custom blend dyes to match your leather or vinyl interior. I used it on my SL to restore the seats. I cut a piece of the center console off right under the armrest where it meets the rug, sent it to them and got a perfect color match. The dye goes a long way and it is some of the best money I have ever spent! I highly recommend using their dye to match your new vinyl to the rest of your car if you want it to match better.