Mounting door speakers.

[Peter Bull]

Hi, I have seen a couple of questions conserning mounting speakers in the doors and thought I would show how I did. Hopefully it will be of some help or inspiration.

The PO must have been in a very creative mood when putting in the door speakers. The speakers were a little to big to fit the holes in the doors so they were fixed with a bunch of 50 mm long self tapping screws. To hide this he had used a couple of meters of black electrical insulation tape. It did not look too bad from a couple of meters away. But you sit quite close to the door in a 911... In addition he had used about 11 meters of speaker cable, for each speaker. No kidding, they reached about one full lap around the car!

I have no pictures of this because I was afraid the camera would self destruct.

The speakers are 165 mm (6.5 inch-ish) two way, and a little too big for the original hole in the upholstery and door carcass. So I took a couple of 12 mm thick MDF boards to use as distances and to fix the speakers. There are four tee nuts in the rear for the screws to fasten the speaker, and four conutersunk holes in the front for the screws to fix the frame to the door. Since MDF absorbs water I painted the frames.



There was a plastic cone in the door to protect the speaker from water dripping down along the window, but that was to small. Using two layers of 200 g/m2 carbon fiber twill weave and a little epoxy I made new cones which were big enough to house the speakers.



To to fit the speakers took a little persuation. There were a lot of holes to line up, but it turned out quite ok in the end.



Disregard the small tweeters, they are part of the PO's creative streak, and are used to cover up the holes they would leave if I remove them.

/Peter

[randywebb]

"I have no pictures of this because I was afraid the camera would self destruct."

Nice post, BUT we KNOW you have pics...

[dezzmo]

That's good work Peter. I'm sure this info you posted will help out a few people who are looking to install door mounted speakers.

[Peter Bull]

Originally posted by randywebb
Nice post, BUT we KNOW you have pics...

Sorry, but I was to focused on the task to remember taking pictures. And I didn't really want to put the pieces back again for a photo session.

You didn't miss anything.

/Peter

[UK Carrera]

Great post - any chance you could publish the template for your MDF spacers??

Thanks!

[Peter Bull]

Originally posted by UK Carrera
Great post - any chance you could publish the template for your MDF spacers??

Thanks!

It is just a piece of cardboard, but I'll see if I can transmogrify it into an electronic format.

/Peter

[Dan in Pasadena]

Peter, Thanks for this thread.

My PO apparently spent a LOT of money on the old system in my '76 with a seperate graphic equalizer - '70's style. A separate cassette deck, etc. I ripped all that stuff out.

My problem is the installer did a hack job of increasing the size of the factory speaker holes in the doors. He did it with tin snips and it looks awful. All chewed up!

So my interest in your project is the MDF spacers. I need them more to re-create a nice round hole and a flat surface to mount new speakers than as spacers per se.

Did you use a large hole saw to cut the holes first and THEN cut the outer size? I ask because the margins around the edge of those spacers looks pretty thin and cutting the outer shape first would probably result in breaking them. Did you have any of those problems?

[UK Carrera]

Thanks Peter - that would be great!

[Peter Bull]

Dan,

I cut out the outer shape of the spacer first and then carefully with an electric jigsaw cut the hole for the speaker. There is a retaining ring for the grille which fits nicely around the speaker. I used that to mark out the hole in the MDF board.

The MDF board is quite strong, so it was not difficult to make the holes. I did it in four sweeps, making sure that the rest of the spacer had good support.

The recess that the spacer sits in, which limits the height of the spacer, is about 6 mm deep. So you don't have to use a 12 mm thick spacer, but the upholstery hides the extra thickness. And the extra thickness makes the spacer quite stiff.

/Peter

[Kroggers]

Nice work Peter. Where are you at the moment - Denmark, Sweden or Norway??

[Peter Bull]

Originally posted by Kroggers
Nice work Peter. Where are you at the moment - Denmark, Sweden or Norway??

Thanks Pål! I'm in Denmark pining away in my office in the nice weather. How about you?

/Peter

[Kroggers]

Just like you. Siting in the office in Stockholm, dreaming about working on my 911 and drinking beer!!!
So, when you going to come over here and help me fit the new torsion bars and lowering my car

[Peter Bull]

Originally posted by Kroggers
So, when you going to come over here and help me fit the new torsion bars and lowering my car

I have to lift my own car a couple of cm's. The left rear wheel touches the inside of the quarterpanel under hard cornering. I thought I do that first to brush up a little on how to do this.

/Peter

[Kroggers]

Originally posted by Peter Bull
I have to lift my own car a couple of cm's. The left rear wheel touches the inside of the quarterpanel under hard cornering. I thought I do that first to brush up a little on how to do this.

/Peter

OK, I will keep the beer on ice

[Peter Bull]

Originally posted by UK Carrera
Great post - any chance you could publish the template for your MDF spacers??

It took a little time to transmogrify it from cardboard to Catia but here it is.



I can not guarantee that the spacer will fit, some data may have been missed in the transmogrifation. And the image is not full size, therefore I have added the measures. Hopefully that will make it a little easier to scale the image back to true size.

You will have to adjust a little to some of the edges on the rear side. The red marked areas. I used a file.



I did not mark out holes for the screws to fasten the speakers. It is better that you use your own speaker to mark out the holes.

The right side is a mirror image of the left side.

/Peter

[KS120196]

Originally posted by Peter Bull


There was a plastic cone in the door to protect the speaker from water dripping down along the window, but that was to small. Using two layers of 200 g/m2 carbon fiber twill weave and a little epoxy I made new cones which were big enough to house the speakers.



/Peter

Nice work! How about some details on creating the buckets? I don't have access to an autoclave.

Frank

[Dan in Pasadena]

Frank,
I will be doing this little mod myself as I postedabove. I am thinking you could find adequate speaker cones in the Crutchfield.com catalog. At least that's my plan! I know NOTHING about working carbon fiber.

On the other hand in Southern California and as little as I drive the car when it (rarely) is wet here, I probably do not need to protect them....well....I suppose for when I was the car!

[randywebb]

any car stero shop should have them - the CF is a nice touch! but not needed

I think you only need to autoclave it for the highest strength/wt. ...

High density mdf will make a nice mounting board.

[Peter Bull]

Originally posted by KS120196
Nice work! How about some details on creating the buckets? I don't have access to an autoclave.

Frank

Thanks Frank,

you don't need an autoclave. At least I did not use one. I used vacuum infusion, but I think hand layup would give a good result too.

The mould was made from a piece of plywood and a block of Divinycell H200. I cut out a cone from the block of Divinycell using a bandsaw, smothed out the surface with sand paper, and put on a couple of layers of epoxy. The plywood was used as a base for the cone and made it simple to make the flange. Instead of Divinycell H200 you could use building foam, which is really easy to work with. I didn't use that because it can not withstand polyester or vinylester, it melts at a relatively low temperature, and it does not withstand pressure. If you are using hand layup with epoxy it should work just fine.

I draped two layers of 200 g/m2 2 x 2 twill weave of carbon fiber over the mould and infused vinylester or epoxy into the dry fibers using vacuum. Vacuum infusion requires a vacuum pump and some consumables such as a vacuum foil and tacky tape to seal up the mould with, a distribution medium and peel ply can also come in handy.

Originally posted by randywebb
- the CF is a nice touch! but not needed

Oh, you are so wrong No, seriously you cold use a weave or CSM of glass fiber or even a glass veil shold work.

/Peter

[randywebb]

"Oh, you are so wrong"

I need a new tub - will you hand lay up one for me?