boom boom- finally finished up

[Irvxing]

You got any sound deadening in that trunk?

[AlexN09]

Title of thread led me to believe I was going to see a video of a Mazda 3 exploding
But after seeing the whole thread I am impressed with the work/time put into the sub box.

Haha thanks Keller! I really hope it turns out well. I would be so sad to see my work go to waste if it cracked or something.

[DJ_B_Easy]

I would be so sad to see my work go to waste if it cracked or something.

Just take your time and it wont. Reinforce everything double what you think it should be and you will be fine. I rushed the final stages of mine and after two years or so its starting to show sings of structural wear.

[AlexN09]

Do you have any pictures of yours? What exactly seems to be wearing down?

[AlexN09]

You got any sound deadening in that trunk?

No I don't but I have a feeling I'll get some because I HATE that terrible trunk lid sound lol

[DJ_B_Easy]

Do you have any pictures of yours? What exactly seems to be wearing down?

Mine is an amp rack (I think I said that earlier but not sure). Same principles of FG though. There are seams at just about every curved edge, and they are starting to show through the Bondo and paint. Nothing major like chipping or cracking, it almost looks like a weld but they were 100% smooth originally. I guess after two years of subwoofer punishment from behind (LOL) its just starting to give a little. I think if I had used more resin at the seams it wouldnt have been an issue.

[AlexN09]

Wow cool! I would have never thought about replacing the back seat with a custom amp rack. That's pretty neat! I think I'm going to make a plain steel mount on the same side as the box further back against that same surface. I'll only have one amp there and in the future I might mount one under the dash/consul for the mids/highs.

Saturday night I'll be driving back home and I'm gonna borrow my dad's sanding tools and get to work on finishing this thing.

I'm really torn between just carpeting it and calling it a day or painting it Paint would look so cool but would just add more cost and time to this

[DJ_B_Easy]

Dont think that carpeting is going to be easy either. Paint requires a lot more prep of the surface but carpeting around that many complex curves and edges is not a walk in the park. I originally had the amp rack upholstered, hated it because it just never layed right, ripped it off and painted it.

[AlexN09]

Haha I know! I really have no idea how I'm gonna carpet it really well either because even stretching that fleece was a tough job with all of the curves and stuff.

It seems like I could get the thing prepped right for paint and I have air guns and hvlp guns and stuff for priming and painting. I just am not quite sure if I trust my bond/paint job to last to hold up to the sub forever without peeling/cracking.

[Irvxing]

You got some love stains in this pic DJ B Easy

Working on sound deadening my whole car

[AlexN09]

Awe man please come and do mine!! That looks great. I'm not too worried about the sound quality and road noise, I just don't wanna sound like my car is rattling apart.

This is where I'm at right now:


No sanding yet and no interior fiberglass reinforcement. There's still quite a lot to do.

[audtatious]

If you end up with less than 1cf then throw some polyfill in there. 1lb of loose polyfill per cubic foot can boost the enclosure by about 25%

[AlexN09]

Wow a pound is quite a lot of polyfill!! Thanks for the tip, I had heard that but I didn't know how much to use.

[audtatious]

http://www.moodym.com/audio/fiber.html

That should help.

[AlexM.]

This is an awesome thread. Definitely a breath of fresh air compared to what we've been seeing lately. Nice work!

[AlexN09]

Haha thanks Alex! I completely agree. Honestly that motivated me to do it. I was thinking nobody has done something like completely custom like tho in a while and it could bring up a lot of good points about fiberglass construction and stuff. When I get a little more time I'll really finish it up nice and make my time worth it.

[DJ_B_Easy]

You got some love stains in this pic DJ B Easy

Ha! That is entirely possible, but I highly doubt it. The car got filthy building that thing and those pics are from the first time I installed it.

This is where I'm at right now:


No sanding yet and no interior fiberglass reinforcement. There's still quite a lot to do.

Dude you are not going to be able to sand down those lumps of resin on the left side. You are going to have to use Bondo, no way around it. When you have big globs of resin like that it kind of heats up when sanded and destroys your paper/orbital pad in minutes. It almost transfers to the sanding surface, I cant really explain it. You can give it a shot but they look pretty intense. Plus, Bondo is fun!

If you end up with less than 1cf then throw some polyfill in there. 1lb of loose polyfill per cubic foot can boost the enclosure by about 25%

^And this...

And, Id test fit your sub before going to much further. Just saying...

[audtatious]

You could use a rasp to get the big lumps down. Bondo is somewhat a pain and quite messy/dusty (my wife had a fit with all the dust in the garage when I was working on my last box). Don't use too much hardener or your work time with the Bondo is short and you will have to do smaller batches (upside is that you can begin sanding and working it earlier).

[DJ_B_Easy]

^True, even an angle grinder maybe? I didnt have one of those and had already bought so much I couldnt spend anymore. I can definitely say sanding it is not the way to go.

I didnt have too much trouble with the Bondo, for me that was much easier to work with than the FG and resin. Its definitely a mess with dust though.

Alex where is our daily update???

[AlexN09]

Haha okay b easy this one's for you!!

SO I broke down and bought the dremel, random orbital sander, rasp, bondo, primer, and lots of sand paper grits up to 600wet




Tonight I'm going to finish up all of the fiberglass work and then I'm moving onto bondo and lots of sanding/smoothing.

Later tonight I'll post up the sub and amp I'm making a trade for in a couple hours. Hold on tight because I am going to get this going back at full speed again !

I can't wait to get the sub in and make sure everything fits haha

[BlackMamba08]

wow...this is moving along real fast. i spent months working on mine, although i only worked on it on my free weekends...

nice job so far!

[AlexN09]

Do you have any pics of yours? I have seen your build thread but I don't think there was any audio stuff involved.

[AlexN09]

Sub and amp are in and wired. The box is structurally finished and works like a champ. I still need to do the finish work to make it look as sweet as it sounds.

I'm running the 3rd generation alpine type r 12 sub with 4ohm dvc. My amp is a kenwood mono block class d amp and it's currently drawing a little under 500 watts wired at 2 ohms.

I spent a little time tuning the amp in correctly and the sub sounds fantastic. I love the sealed box so much it's plenty loud enough on rap stuff and can really get low in the frequencies. It really sounds fantastic on softer rock stuff as well as country music. So far my system really shines playing dub step stuff. The bass has almost no lag that I can tell and responds really quickly.

Now I'm gonna need to build an amp rack and finish the box!

[DJ_B_Easy]

PICS OR GTFO!

[AlexN09]

Haha my name doesn't start with d3santis!!!!! Gimme a sec I'm in class

Alright here's the picture of basically a mock up of the final setup:


I'm going to finish the box in Nissan-Ocean Grey and I need to figure out some way to mount the amp.

This is where I need help, I wanted to just take a single piece of sheet metal and bend a mount that would sit flat against the bottom of the amp, and bend out at the top and bottom to mount out to the wall. The problem is that the mounting surface inside the trunk has complex angles and isn't really square to the floor or anything. How would you go about mounting the amp?

[BlackMamba08]

Do you have any pics of yours? I have seen your build thread but I don't think there was any audio stuff involved.

I carpeted a small piece of wood set perpendicular to the floor and mounted my amp against that. i think there's some other guy blkmomba or something like that with the build thread...i never got around to listing my build. but this is my amp and sub setup.

[AlexN09]

Oh wow that looks great buddy, thanks for posting!!!!

I like how you maintained the grocery net function I unfortunately lost that haha I didn't even think about carpeting some wood, I could easily make what I want out of wood. I am trying to mount my amp at the same angle as the sub is sitting.

Do you think your sub has enough airspace? I was worried about mine and it seems a little bigger than your box.

[BlackMamba08]

my box is a little smaller than most. I put in a lb of polyfill in there to make the sub perceive that it has more space than it actually does. i believe the rule of thumb is that for every 1lb of polyfill, the sub enclosure space is perceived to have increased by ~33%. i think it's about 30% or so... don't quote me on that. it probably could've used more...but i rarely turn my volume past 1/2 way anyway, it still hits really hard and clean.

[AlexN09]

That's great man. I just wanted to save space and increase the sound quality and I'm really happy with this setup I've got. I might upgrade the amp at some point but I'm guessing that 500 watts is about max for the enclosure. I would hate to break it or something, I might be overly cautious but I put a lot of work and money into the construction. Did you make that box yourself?

[BlackMamba08]

yeah... i was a little worried too, so i put many layers into it because i was worried about it breaking... but it's pretty sturdy. it was a lot of trial and error with fiberglassing. but it finally came together. after working on it, i realized why i was quoted so much for a custom enclosure, it does take quite a bit of work.