Yeah very good write up. Im a car audio junkie so reading this gets me stoned with inspiration. I know how to design and tune boxs and such but i have never attempted fiberglass yet. its something i have been wanting to do for a long time and the time is soon. Im done with my audio set up right now except for a fiberglass box. (ignoring the fact the my sundown amp randomly stops giving output) My biggest issue is i allways like to start big. I currently got a slot ported 3/4mdf box tuned to 28hz with 2.5cu ft chamber excluding the long *** port. I designed it for an fi audio 12 inch q and i make people poop themselves when they get in my car. especially because of the fact that only 1 12 is doing all that damage. It sounds fantastic but i have heard mixed things about the sound quality of fiberglass. I do know that if i did it i would do it in the trunk facing backwards and know from experience that that tends to be cleaner sounding. But when it comes to fiberglass/wooden box to wooden box what do you think sounds better and is it really a big difference? cause i can stand up to a 10% loss for looks but no more than that. Allso if i was planning a big fiberglass box in the trunk what would i do about the spare tire well? I know i could fiberglass that and incorporate that into the box but its just kinda at a really inconvenient spot. And how do go about running speaker wire into a fiberglass box?

 

Nice write up... I still want your doors lol. I hope you don't mind me adding one little thing... there is a fabric by the name of ponte that can be used in place of fleece... takes a lot less resin to wet out, and a lot easier to stretch. I love your rear deck...

 

There are a couple of components to this- one is it can take a good bit of fiberglass to get the stiffness of MDF, depending on the shaping (especially true if you have a lot of flat area)- another problem with boxes that are almost entirely fiberglass is calculating size- since you've got all kinds of curves and such.
Definitely the way to go- when I did my backseat box- I not only went a little over manufacturer spec for box volume, but also lost the loading effect- so my subs got significantly sloppier. That combined with the db loss was enough for me to sell it. It was more for show than anything anyways.

Honestly, for people that are very concerned about db- I typically still do a wood box like normal, then either make a false front out of fiberglass, or make complete cover panels. The box will end up looking bigger- but that way you know it will still have the wood box sound, but you'll also have the custom fiberglass look.

I usually have just gone over it, and ignored it was there- maybe used it to house some distribution blocks, or some wiring or something. In my monte, I put my battery in there. The bad thing with any really custom trunk audio install- is that you usually end up losing easy access to the spare tire. You could get a compressor pump/tire sealer like my GXP comes with in place of the spare- that's pretty small and easy to hide off to the side or something; but if you shred a sidewall or have a huge gash- you're screwed.

Not much different than a wood box- you can still liquid nail / screw a normal terminal cup in- or you can just drill a small hole- run the speaker wire through it- and liquid nail the hole shut (obviously not as good if you have to remove it often though).

Honestly, they may be for sale by the end of the year. I'm at a bad spot now with audio- since all the other audio components have been stolen; I just don't know if I can justify spending all that money again, and I don't know if I want to waste the money on a lesser setup. So I have thought about finishing the doors completely (since they're mid-project now with the crossover windows and I've already got all the materials)- and just selling them.


Definitely not- the more information we can get in these kinds of threads, the better!

Never heard of ponte before- where do you get it from?

There is definitely a lot of more advanced stuff that I didn't add above (special tricks and such, and more advanced processes- like vacuum bagging and such)- I just wanted to get some basics out there so people could get motivated to try to build something on their own- hence why I tried to keep the materials list down to stuff you could pick up at any local shops.

 

is that an earthquake PHD2 "shredder" amp? looks like one. i have one that needs repair, they can make 2000W rms and 3200W peak.

 

is that an earthquake PHD2 "shredder" amp? looks like one. i have one that needs repair, they can make 2000W rms and 3200W peak.

 

Not sure which is in the pic- I did used to have a D2 (that is what the rear deck was originally built for)- but ended up upgrading to the D3- that thing was a real monster. Ran the thing daily driven at 1 ohm, and never had a problem.

Its too bad it got stolen, along with the subs

I don't care for any of the new Earthquake stuff.