How to install midrange & midbass speakers into an R36 Passat door.

[Fhrx]

Hey guys,

After doing the Golf tutorial I’ve had quite a few people email me asking if I could throw a quick tutorial together on how to install the midrange and midbass speakers into the R36 Passat. We just recently did r207’s Passat so I’ll run through his doors.

Step one: Take one original door complete from factory.



Step two: Apply sound deadening to outer skin.



Step three: Add diffuser panels behind the midbass speaker but not the midrange. The midrange will get its own aperiodic mat later.



Step four: Make the baffles. These take a similar shape to the factory ones and screw into the factory screw holes (thus avoiding damaging the door). We usually use netserts in the large holes left when the rivets are taken out. These inserts basically sit in the hole and provide a thread to bolt into.



They baffles themselves are 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. In behind the midrange driver we also put numerous small air holes and run an aperiodic mat behind the driver itself.



Step five: 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.



Step six: Screw the baffle onto the door and seal the baffle onto the deadening with gap filler. 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 seven: Solder the trimmed speaker wires onto speaker. Don't use crimp terminals because their two best traits are falling off and creating resistance.



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





r207 uses Focal Utopia which has screw down terminal blocks build in so I’ve included a couple of DynAudio photos so you can see the positive and negative terminals soldered and heatshrunk.

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



So there you have it; one Passat door with midrange and midbass drivers installed. Using this method you have about 78mm of mounting depth for the midbass and around 32mm for the midrange. Any deeper than that and you might have incur some serious headaches regarding metal and/or glass contact.

[Fhrx]

Now that you have your strong front end sorted out playing up from 60-70Hz, you might want to start thinking about a serious solution for the 60Hz and down subsonic region. This is the rear end of r207's Passat and is well worth considering if you want to hear and feel the bottom octave without losing your entire boot.

[Spyda]

Very pro, i like it.

[Cousin]

Very neat work, fhrx
Particularly love the sub setup


M

[Swallowtail]

Looks great. I'm sure it sounds great too... Thanks for posting this up.

[Rybky]

That is awesome, the sub setup especially is really neat.

Where is the amp for the sub?
How much space is there behind the sub speaker? Seems like a large speaker without much air space.

Has got me thinking about what I can do now!

Adam

[Fhrx]

Where is the amp for the sub?

The car actually runs four ARC Audio KSMini's under the floor. There is plenty of space at the front of the boot for them and the BitOne processor.

[Fhrx]

Seems like a large speaker without much air space.

One of the most peculiar aspects of the Utopia 33WX2 is that in order to get a Qtc of 0.707, they require an absolutely minute enclosure. We aimed for a Qtc of 0.707 in the Passat wagon because the subwoofer is firing in the same chamber as you (however in cars like mine the subwoofer has to fire though a seat so we tend to raise it a little to a Qtc of 0.74). Have a look at the following graph showing the Passat's subwoofer linearity and group delay.



As you can see; it has a stunning response and a constant group delay (making the bringing of the bass to the front easier), all in a very small enclosure. The enclosure is so small in fact that the subwoofer motor almost didn't fit in. Luckily r207 required a slightly larger enclosure than mine. My 33WX2 has to sit bum out like this: