2021 Mirage

[Impossible Bill]

Starting to work on my DD. System plan is:
Source - OEM head unit, convert signal to digital plus a mobile phone to have digital out with pdt on factory display and steering wheel controls.
Front speakers- Bliesma T34B and Purifi PTT6.5X04.
Sub- Hybrid U12SW
Amp / processor- Harmony 8x12DL

May switch source if i find a unit I like with toslink out. Space is important so sub is in spare tire well snd amp under pass seat.

Tweeters are playing to pick location along with old focal K2P in the door since Purifi won't like that location. Will also be fitting a larger 135A mitsu alternator once i can fab new brackets.

I think that covers current system details, we'll see how much that changes as things progress.

[Impossible Bill]

Started preparing for PTT6.5 mounting while waiting for tweeter brackets to be machined.


Trailer light housings are used to hold the aperiodic membrane in the sill panel. The shape and surface area should work pretty well I think. I made a gasket, cut mesh to fit and bonded with 3M 5200. These are also bonded to the car the same way.


A rubber trailer gasket that fits inside the trailer light housing will attach to the kick panel that also has mesh. This will seal and sandwich the membrane material and it wont be too difficult to remove the kick and get the correct amount of damping material between the enclosures.


Next will be mold of the floor to start building the kick panels.

[Impossible Bill]

Started working on the kick panels this weekend. Made my mold so I could I line up the trailer light rubber insert with the housing mounted to the sill. I fiberglassed a Steel trailer light mount to give me a smooth surface and position the rubber gasket. This seals the kick panel enclosure to the sill enclosure and holds the damping material.


Then I routed mounting rings and positioned the baffles. I am using the angle used for the tweeters. Since they are large I bought cheap fog lights on Amazon and mounted the tweeters in them. This let me temporarily place them and adjust their axis easily. (They'll be tackled next now that I have the desired position and the waveguides are done.)
Here's a sneak peek at my WG used for fabrication. They are PLA and once fab is done the metal pieces will be installed.


Back to kicks, wrapped in fabric and resined to hold shape. I always use epoxy resin for strength when bonding to plastic.

Inside was fiberglassed and test fitted again. The OEM stud on the firewall and push clips in the kick panel ate still used and they are formed to the floor and against a support rail. They can only fit in 1 position so the AP membrane will be sealed if they are. In position.


I made a recess along the inside edges on the bottom so the carpet and floor mats can be tucked in and look like they belong once trimmed.

Outside being fiberglassed next and will be finished with SEM. I sent an interior piece out for paint matching.

[Impossible Bill]

Made some more progress on the kick panels. Bondo and sanding, I seem to be the only one that likes the smell of that stuff.
Got the first coat of color on too!

Kidding, left over paint from making cosplay weapons for my daughters...and want to see if anyone's paying attention. I may come from the era of speckle paint, fleckstone and krylon on anthing plastic you can pry off but not ever my thing.
I like to put some color on and sand with 220 to make sure they are smooth enough for finishing.

[Impossible Bill]

I was able to put texture and color on today after I installed the threaded inserts. I coated the baffle with epoxy resin before installing them.



Here's the rear view showing where the AP membrane is compressed into the sill panel.


No time this weekend but will damp the enclosure and start DATS measurements soon I hope.

[Impossible Bill]

Damping with 10mm felt done today. Hope to get baseline impedance curves tonight. I plan to weigh the membrane material to hopefully speed up fine tuning.

[Impossible Bill]

Kicks are in...sort of.

I need more membrane material than I anticipated. The amount I need is more and creates mounting pressure to compress. I have a few options i think.
1. Bolt in kicks to compress it more. Not too difficult.
2. Find material denser than Rockwooll
3. Compress some material in housing built into kick as baseline. (Looks like 12oz is safe)
4. Add depth to the housing built into sill ( plenty of depth but sealed to car and hard to remove)
Open to suggestions and will let them break in while i give it some thought. Already night and day from the Focals in the doors.

Here is free air. 60 ohm impedance and phase shift at ~35hz fs.


Here is with membrane I can fit. ~10ohm impedance and better phase response.


Will work on waveguides while I fine tune AP setup.

[geolemon]

So are the membranes to cover the 6.5's like grilles?
I ask simply because I WISH I could do drivers like that - we get so much snow and slop in the winter, wet feet and all that - and even if not I'm sure my fiancee would put her heel right through.

But with membranes covering them - that would solve that.

[Impossible Bill]

No, its a 2 chamber aperiodic enclosure. The kick panels are small sealed enclosures. They are connected to the sill panel of the chassis which acts as a larger enclosure. The "membrane" is the material that meters the amount of air that passes between the front (small) and rear (large) enclosures. This damping lowers the Q of the small enclosure and reduces the impedance peak at Fs. I use a DATS V3 to tune the amount of material needed and am using Rockwool and fiberglass insulation here.
These drivers added midrange detail and improved midbass response. A friend and former IASCA expert WC listened to the car with the Focal K2P in the doors and said the everything sounded great except for the missing midbass. Loved the sound from 500 up and the tweeters did really stand out. Now that midbass is is much tighter and articulate without any tuning adjustment and the mids/tweeters blend together.
Making some different and more permanent tweeter mounts and will hopefully be ready to dig into tuning soon. Then i'll get some people in for some listening/ critiques. Wanted yo get to NC to the SQ event for that reason. Haven't seen Keith in 17 years. I highly recommend these drivers but as always implementation and tuning are the key. They aren't going to be ideal dropped in a door.

[Impossible Bill]

Started on the pillars. Since the waveguide / tweeter combo will weigh 8-10lbs i decided to give them a solid base on the dash and mount to the car rather than the pillar trim. The airbags added some challenges, i can't go above a certain point and have to make sure the trim will break away and the tether will function as intended.
Plaster mold so i didn't have to resin in the car, set a mounting ring at the desired angle and stretch cloth to glass over.

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Through the mounting hole you can see the dog light bracket. I used that to determine the angle i wanted to mount the drivers on. That will be removed when the brackets are installed to secure the pillars.


I have mockups of the waveguides printed and attached some wood to include tweeter dimensions to ensure fitment.


I'm debating how to finish them. Do i go with the brig beige of the pillar trim, get off the dash or good black to match the dash trim panels?