View Full Version : Project: Audi Midbass Worklog

07-01-2006, 03:20 AM
Got tired of my crappy midbass... I had literally NO midbass..

Then i tried speaker baffles (foam cups) and they helped ouput a bit, but the stupid baffles themselves rattled and make crap noises, and my entire door panels rattled...

So finally, i decided to spend this 4-day weekend revamping my component installs. I didn't do the work initially, i had it done by a shop so that it would be done 'right'...

well, 'right' ended up looking a lot like this:


yup, that's right, they just cut a hole in the middle of the factory plastic speaker grille, and mounted 'em up..... Thanks, guys.

So today i gathered up all my equipment, went to lowes to get a roll of that cheap rubberized asphalt mat, and was ready to go to town on my rear doors (starting small here...)

My initial plan for p:Am was to put a 10"x10" piece of dynamat xtreme behind the speaker, and then deaden the top door panel completely, sealing all holes, with the cheap rubberized asphalt, creating a true IB install, opposed to my rattling, door-panel-mounted crap install above ^^....

Well, was i in for a treat.... I got the first door panel off, and my mouth dropped...

This is what i saw:


...... anyone who cares about proper door installs is crying right now....

There's nothing IN THE DOOR to dampen!!! There is no outer metal door, the factory speakers were actually installed IN THE PLASTIC DOOR PANELS!!!

At this point, i'm just crying, sitting by myself in the dark, wondering why in the hell i decided to get rid of my jetta, which was a perfect car for stereos, and get this audi, which evidently was NOT designed for stereo overhauls....

So now this turned into a project real fast.

I had two options,

#1) deaden the crap out of the ^^ inner door panel, which already has a gigantic tar mat covering the entire thing (futile) and deaden my plastic door panel, and HOPE for no rattles, and convince myself it's ENOUGH of an infinite baffle install for it not to bug me constantly...


07-01-2006, 03:37 AM
#2) turn lemons into lemonade, and go balls to the walls:


I decided (obviously ^^) to remove the factory speaker grille, as well as the storage compartment in the doors, and do a ported cabinet, a la cabinet speakers.... mounted into the doors.

The above pic is just a test fit of the baffles i made, they already look 100% better than that hackjob i had before, so i'm gettin' motivated.

So i get my baffles ready, i decided to use the factory speaker location, so i cut my holes, and started designing the walls of the enclosure around the speaker location:


got the walls completed, next was to screw them together, and level the top and bottom of the enclosure walls, to make a nice seal:


The bottom piece is going to suffer the most direct vibration, so it was cut from 1/2" plywood rather than the 3/8 i used for the other sides, and also dampened with dynamat:


gorilla glued all the walls together, and then the bottom piece to the walls with gorilla glue for a nice air-tight fit, and compressed with lead:


designing the initial enclosure was the hard part, so i popped the other side out before the glue was even tacky:


07-01-2006, 03:37 AM
once the glue was tacky to the point of not shifting around, i centered my front baffle onto the enclosure, dropped the speaker in for fitment, marked how the baffle would finally sit on the enclosure, and then glued, screwed, and compressed it:


while both were compressing with the front baffles attached, i picked out my covering. I decided to go with a koroseal vinyl wallcovering. Good damping qualities, as well as being water and temperature tolerant, plus the color was **** :naughty:


once the glue had all dried to a tack, i flipped the enclosures over, glued to the vinyl, stacked them high with lead, and this is how they'll be sleeping tonight:


i'm about to follow suit (minus the lead) but tomorrow i plan to finish the vinyl, recut the speaker holes, and get these bad boys mounted up.

Rather than speaker terminals, i'll just be cutting airtight holes into the back of the enclosure, and caulking them in.

Then as my final step, i plan on blasting a 55hz tone, and drilling 1/16" holes in the opposite side of the baffle from the speaker (where the storage cubby was) until the suspension gives out, or output rolls off, and then increasing my x-over to a 70hz 24db/octave slope.

I'll keep ya posted :D

07-01-2006, 04:45 AM
**** you are doing a phenomenal job! Keep me updated!!!


07-01-2006, 08:26 AM
man u got the shaft from that shop all they had to do was build a little baffle and mount it in the door, that way they didnt wreck ur door panel. are u still gonna deaden the door? and it is looking great, keep it up man

07-01-2006, 01:20 PM
man u got the shaft from that shop all they had to do was build a little baffle and mount it in the door, that way they didnt wreck ur door panel. are u still gonna deaden the door? and it is looking great, keep it up man

the door itself is pretty well dampened from the factory, the doors make a loud compression 'thud' when you shut them, and road noise is null when the doors are closed with the windows up, my main objective for damping was going to be sealing the doors to create an infinite baffle, i could actually see light around the cracks of the plastic door panel, so midbass was never gonna happen without an enclosure of some sort, too much cancellation.

i'm planning on deadening the plastic door panel to prevent rattles, mainly behind the enclosure, and also on the front of the panel, where it's going to be mounted on.

the cheap-o deadener i bought was the ownes corning kind, rather than the more expensive good kind, and it actually has shingle-textured paper on it :( so i gotta cruise back to lowes and return it. The kind with foil on the back costs like $30 more for the 100 square foot roll....

so i'm about to head to the bank to get rent, hit lowes and home depot, and get back to work.

thanks for the encouragement, i'll keep you guys posted, i'm still not sure what i'm gonna do for the fronts, i honestly might have to just fab up covers, and do kicks, cause those speakers are HUGE, and look like crap in the doors!


07-02-2006, 04:03 AM
forgot to bring my camera home from the shop tonight, but i'll get pics up tomorrow.

Got both sides done and installed, and they sound way way way better.

I've got the alpine mids in the enclosure x'ed from 80hz to 200hz, and then have my kenwood component up front x'ed @ 200 and above. Subs @80 and below, of course.

Noticed a strange problem, tho. With my subwoofer turned off, the front components and the rear components blend beautifully, sounds like a true 3-way setup, great bass, great highs, great fill, great greats. But when i turn my subs on, the rear components and the subwoofer don't seem to get along very well... If i fade to the front, the subs are punchy and clear, but when i fade 50/50 or to the rear, something sounds WEIRD, and there's no output from the subs..... By weird, i mean WEIRD, sounds like the music is vibrating, imagine someone talking to you while sitting on the washing machine (or maybe moaning) it's bizarre.

I'll have to play with phasing tomorrow, and get to the bottom of it. Till then, i'll just not worry about it, i'm sure it's something stupid.

Oh ya, but also now my car thinks all the doors are open, the dome lights don't work, and none of my windows roll up or down!!!!

I'm guessing something's disconnected in one of the doors :) Small detail.

07-02-2006, 04:11 AM
let your alpine mids play down to 50hz, and then low pass your sub at 50hz and see how that sounds.

07-02-2006, 06:44 PM
well, cool cool cool

played with the phasing of all 4 doors today, turns out i had a few miscelaneous problems, turns out my drivers' side front woofer is spliced somewhere along the line, thanks again to the original installers, so a few months ago when i 'fixed' my phasing, i actually reversed it.

Got a 9v battery, and got all my phasing taken care of, and WOW, that fixed it.

I'm blown away by the difference midbass has, and i'm glad i decided to lose the rear tweeter as well, it sounds so much better without it. Plus, now that my rear doors are my midbass speakers, i can use the fader as a midbass volume control, which is excellent, some recordings sound like poop with it, while some i'm completely rediscovering WITH it, so much music i was missing before :)

Only thing i will say is that midbass definitely increases the difficulty of tuning the speakers. Some cd's want the midbass/subwoofer split @ 50, some 60.... When the entire freq. range between 70-200hz is lacking or missing altogether, recordings are a lot less picky. And my install's now capable of TOO MUCH midbass, which is an absurd contrast to my previous problem. Definitely a NIGHT and DAY difference in those type-r's now that they're in the enclosure. I wouldn't recommend it to anyone that still wants full midrange up to 2500 or 3500, but if you can give up rear fill, enclosures in the back TREMENDOUSLY increased my midbass output, and the soundstage is suprisingly less effected than i thought. Especially because if you look at the pics above ^^ the position of the rear midbass driver in my car is actually closer to the drivers head than the front speakers are. It sounds glorious.

And also, i haven't decided what i'm going to do with my front channels, i kinda like it the way it is now, with my front midranges playing 200-3500, and my tweets playing 3500+.... Putting the type-r's in the enclosures definitely killed my high-freq' output, but definitely puts out enough midbass for the entire car, so i may just end up leaving it the way it is.

So far i've figured out:

Anything acoustic, easy listening etc. sounds GREAT with midbass.

Tool, not so great.

I'm sure i'll get my x-overs perfected eventually, but for now it just seems like cd's are hit or miss.

07-02-2006, 06:55 PM
Listen to something that has REALLY fast Kick Drums, some metal...see how it sounds...cuz Midbass is where the kick drums shine, ya know

07-02-2006, 06:58 PM
what year and model audi?
I have (my GF really) an 2006 A4 I would like to add speakers too but havent found any
door panel removal info.

07-02-2006, 07:31 PM
mine's a c5, 1999

on mine, at least, there's two screws on either side of the door, near the top, then you pop out the window switch and disconnect it, and then you just lift the door panel up, and off.