How to install midrange speakers into an A3 door.

[Fhrx]

Hey guys,

We’ve had quite a few older A3 owners here recently (older version of the car, not older driver that is) and many have repeatedly told us they’ve read that only slimline 4” and maybe 5.25” speakers will fit because if the somewhat miniscule mounting room available to you in the front doors. Many are often surprised then when we tell them that with the use of intricate baffles, 6.5” components will fit so long as they’re shallow. So without further ado; here is a quick tutorial on how to install speakers into the A3 doors.



Step one: Take one original door complete from factory. Remove the plastic foam splash guard (don't stress about water getting through - the deadening will stop it).




Step two: Apply sound deadening to outer skin.




Step three: Add diffuser panels behind the speaker.




Step four: Run aftermarket speaker cables through the door loom tubes. This is important because there's no fuse between the amplifier and the speakers - if the factory wires are too small they'll get hot.




Step five: Make the baffles - this is the difficult part. These have to have a 6.5” retaining ring that is deep enough to allow for the midranges frontwards excursion but shallow enough not to hit the magnet on the window motor. On top of this; they must also screw through the factory 4” mounting holes so you don’t damage the door trim itself (this allows it to be returned to factory when the car is sold). They're usually constructed from MDF but we've made them from perspex or even 6061 alloy depending on application. If they are MDF then they should be painted with polyester resin to avoid absorbing water.




Step six: Sound deaden inner skin and remove all air bubbles. Make sure you leave enough clearance for door handle and lock control rods to move freely. Also leave a little deadening around the top of the speaker hole to act as a 'roof' against water when it rains.

[Fhrx]

Step seven: Screw the baffle onto the door and seal the baffle onto the skin with sealant. Don’t use liquid nails or any other hard glue though because you’ll need to peel it all off when the car is sold and the doors returned to original. Make sure you also install a gasket between the speaker and the spacers because air leaks out here too (ever tried to run your car without a head gasket)?




Step eight: Solder the trimmed speaker wires onto speaker. Don't use crimp terminals because their two best traits are falling off and creating resistance.




Step nine: Heat shrink around the terminals to protect them. Unlike electrical tape, heat shrink will not begin moving after a couple of months.




Step ten: Sit back and enjoy your new found midbass. This is what the door looks like when complete:




So there you have it; one older A3 door with 6.5” midranges installed. Using this method you have about 45mm - 48mm of mounting depth (using 6 + 6mm MDF). Any deeper than that and your speaker magnets tend to hit the window motor cap. The tweeters usually fit in the factory locations with a simple clamp and the crossovers are usually located at the rear of the door.

[Fhrx]

If you wish to read more about what sound deadening, diffuser panels and sealing does click here and click here.
If you wish to find out more about staging, imaging and how our ears relate to them both click here and click here.
I hope that helps you guys out.

[dcc236]

A nice how-to, thank you. What sealant are you using?

Do you use the same approach to fit 6.5" slim-lines to the 1996-01 B5 A4/S4? It has a similar setup to the A3 with stock 4" drivers mounted to the door trim. Unlike the A3, the A4/S4 has very little metal on that door skin closest to the car's interior. How are you fitting sound deadener when there is nothing to stick it to?

[Fhrx]

In the Audi A4’s that have no inner door skin we usually make up the baffle to sit between those inner bars. After sealing them in we then run a layer of deadening over the entire inner skin to seal it all and create a solid inner skin in the process.

[dcc236]

Outstanding!

[emerthis]

Now that is how it's done properly. Thanks for the insight into what is involved with these doors - you couldn't have made it any simpler, and I'm sure it sounds great. I think I may just replace the old 4" units in my 98 A3 with new 4" units - but this gives me pause for thought.