Build Log: 2006 Audi A4 Avant Stealth 24" sub build.

[Pony_Driver]

Great thread, love the pics and your attention to detail.

 

[budget76]

and I thought the 12" Kicker L7 I ran years ago was big. damnn, didn't realize 18's were "small" now

 

[Roc Doc]

im about to set up pvc dust collection on my shop

Check out Project Twin's youtube channel he goes into some depth on his shop setup.

 

[junkytj]

Check out Project Twin's youtube channel he goes into some depth on his shop setup.

Projecttwin goes into "some detail?" Prepares for a 2 hour video on how to glue PVC. Seriously, glad to see you here. I do love your threads and how you show us how to do what you do even knowing I don't possess the patience and skill required to replicate it.

 

[ProjectTwin]

Projecttwin goes into "some detail?" Prepares for a 2 hour video on how to glue PVC. Seriously, glad to see you here. I do love your threads and how you show us how to do what you do even knowing I don't possess the patience and skill required to replicate it.

Don't make me make a video on gluing ABS.

I've blown a few peoples' minds with that.

 

[Murse]

That static isn't bullshit. We had a vacuum system over a few machines in the plant I work at. Static electricity made it go boom one day. Very loud but no one got hurt.

 

[ProjectTwin]

That static isn't bullshit. We had a vacuum system over a few machines in the plant I work at. Static electricity made it go boom one day. Very loud but no one got hurt.

So your manufacturing plant has PVC dust collection piping that went boom?

 

[Murse]

Yes, they took the PVC vacuuming out and went to mobile vacuums. I'm not sure if this is the same set up as yours. But after 10 years of working. It did go boom.

 

[Murse]

Ground well, what can it hurt?

 

[ProjectTwin]

Ground well, what can it hurt?

How do you suppose you ground an insulator?

http://www.woodcentral.com/articles/...cles_221.shtml

 

[junkytj]

How do you suppose you ground an insulator?

http://www.woodcentral.com/articles/...cles_221.shtml

You can't ground an insulator, but I would be grounding where I collect the sawdust. put it in a well grounded metal bin, if you are using a filter bag, drop a grounding plate in it or something. sawmills have this issue which is obviously an extreme example.
https://www.woodbusiness.ca/tech-upd...-control-4759/

They don't use pvc that I've seen in part because of the tech issues you are noting in difficulty grounding. the fires are more likely in the baghouse (collection point) static electricity is a real issue even in grounded systems. We have a flammable dust collection system in my plant and it is grounded 9 ways to Sunday and monitored heavily and we keep 1" of nitrogen pressure on it. It's a bit more flammable than sawdust though.

 

[ProjectTwin]

You can't ground an insulator, but I would be grounding where I collect the sawdust. put it in a well grounded metal bin, if you are using a filter bag, drop a grounding plate in it or something. sawmills have this issue which is obviously an extreme example.
https://www.woodbusiness.ca/tech-upd...-control-4759/

They don't use pvc that I've seen in part because of the tech issues you are noting in difficulty grounding. the fires are more likely in the baghouse (collection point) static electricity is a real issue even in grounded systems. We have a flammable dust collection system in my plant and it is grounded 9 ways to Sunday and monitored heavily and we keep 1" of nitrogen pressure on it. It's a bit more flammable than sawdust though.

If there's a spark in my system it would have to come from a metal object getting sucked into the system and hitting the impeller. That's the only way for it to happen.

 

[ProjectTwin]

Getting the baffle for this 24 welded in.

 

[ProjectTwin]

Some low-power testing tonight. Saw a max of 72 Watts. Showed between 60 and 70 for this section.

The car will need A LOT of sound deadening. Everything shook. The video shakes at the 15 second mark.

The house shook.

 

[Provience]

wow

 

[ProjectTwin]

During the low power testing these cabin vents flapped like mad during infrasonic freqs (below 20 Hz). The locations for these will get welded shut.

Had people worried about how low the motor would hang. This is with the sub in the car. The exhaust is lower.

Have a customer of mine, a boilermaker, that bought a couple of the Stereo Integrity SQL-15s. He's wanting to learn so he's here welding the baffle and everything in the back. I'll be building his wife's car as well.

So progress is still happening on this one. We now have to drop the exhaust to work on the bottom of the car.

 

[ProjectTwin]

A good bit of sheetmetal work. I laid under the car and ran the air saw and body hammer while Sumo welded from the top. I'd work an area, tell him were to tack or stitch, and we'd keep going. Still more to do. Plan is for it to be fitted and look factory from the bottom of the car. No signs of us changing things. The baffle should look like it was there when the car left the factory.

It's dumb, but I like every step to look like a finished product.

Lots of pie and relief cuts to get the factory spare tire well floor blended into the lower baffle.

Also made some block-off plates for the cabin vent openings. Those will be fun to weld into place.

 

[4runner]

Really cool build, thanks for posting this.

 

[ProjectTwin]

Really cool build, thanks for posting this.

Thanks.

We're still making progress on it. Will be back at it tomorrow with more sheet metal work under the car and more welding.

 

[ProjectTwin]

Have gotten a ton of metal work done but nothing that looks different enough to post pics. The cabin vent block-off plates are welded in and there's been a buttload of welding/grinding to blend that baffle into the existing metal of the car.

A couple of days ago I did final fab work on the factory coin holder/cigarette lighter location.

I cut this up and modified it to hold the controller for the Helix processor. There were also some recessed areas on either side of the opening that I filled in.

Yesterday I worked on texture and finish of the plastic work I had done. Today I broke out the flock.

This little flocker gets shit done.

I need to touch up the edges were the flock adhesive crept under the masking tape. That means masking the flocked opening and shooting a little texture/color again. The USB port on the right is where I'll plug in to the car for tuning purposes.

 

[bigun]

 

[ProjectTwin]

Yanked the rear bumper cover to go over the outside of the cabin vent block-off plates.

Will leave it off until we're done with the car.

 

[ProjectTwin]

Hit a major point in fabrication today. The metal fab in the rear tub is finally nearing completion. Have one small panel left to go in and then the finishing process can start on the tub.

 

[nahmus]

It's so nice to watch an artist at work, No matter what the medium.

 

[BCzuk]

Rad

 

[ProjectTwin]

Had a buddy come help on a Ford Edge that I have here for a thrash build before Finals. He owns an auto detailing business and brought one of his guys and got to work on the Edge.

I hijacked the steam washer for a bit and cleaned the Audi's engine bay.

View attachment 119700229_187435049426947_6461284320703435677_o.jpg?_nc_cat=107&_nc...xx&oh=a1289a50ac3838803a414a13

Today I received a bunch of stuff from Second Skin to soundproof the Audi.

But before I get to work applying the materials from Second Skin I first wanted to get the empty cavity in the spare tire well taken care of.

I drilled holes in the top of the 3/16" steel plate that is the baffle for the subwoofer so I could pour expanding urethane foam from US Composites into the void between the factory walls of the spare tire well and the new walls that we built.

The foam we're using is 16lb/ft^3 density.

We initially poured 10 cups with 12oz each of part A and planned on using one cup and measuring out 12oz of part B. Then we'd pour that 12oz of part B into the cup with part A.

The plan was to reduce the number of cups used to do this pour.

Well, part A has the consistency of motor oil. Part B is like corn syrup.

So...we poured 10 cups of part B as well. More cups than I wanted to use, but it got the job done.

Time lapse of the mixing/pouring.



As we poured we monitored flow and expansion of the foam with a thermal imager. The heat from the catalytic reaction allowed us to see what was going on behind the walls.

As we made progress filling the cavity we'd stick down a piece of aluminum tape to force expansion rearward instead of allowing it to come out of the holes. This image shows heat at the highest part of the pour. Between having to tape over the rear-most holes and the thermal images, we knew that the void had been completely filled.

We did the math after we were done pouring and calculated 4.25 gallons of urethane foam mix. The 16lb/ft^3 foam expands 3-4 times the liquid volume.

A brief video going over the process and the sound of this area after it was filled with foam:

 

[Pt_Ranger_v8]

 

[ProjectTwin]

New amplifier that's on the way from Stereo Integrity.

Class AB. Rated at 200 x 4 at 4 ohms. There's no crossover in the input. What comes in goes out.

Will be running this bridged to two channels on the IB-24. Should be 900 or so watts per coil.

View attachment 120959572_191094759060976_3822939601620501986_o.jpg?_nc_cat=106&_nc...xx&oh=546e3cd17e6a7bc044c5baa3

 

[Mattafact]

That's one impressive amp. Didn't see it on the website though.

 

[ProjectTwin]

That's one impressive amp. Didn't see it on the website though.

Prototype.

I have 75x4 and 125x4 protos here as well.