Sub box fiberglasser in Auckland/North Shore

[jcerecke 2]

Finally getting around to upgrading the speakers in the e39. Just purchased the Stereo Integrity BM mkIV shallow 12" sub. This is the latest edition of a legendary shallow sub that only needs 14-16L of enclosure volume. I'd like to replace the existing sub above the battery with this one in a custom enclosure, but I don't think I'm skilled enough to do it alone. I just had a quick measure up and making it out of MDF would be a nightmare if I'm trying to get 14L as it would need 20 different sides of all angles to fit the nooks and crannies.

So does anyone know someone with fibreglassing skills capable of making a box to fit snug in that location? I really don't know anything about fibreglass manufacture.

[jcerecke 2]

Thanks for the advice. I've been doing a lot of youtubing this weekend and I'm keen to do it myself now. I'll be only doing one so should be pretty straight forward. I'm hoping to build the box straight onto the existing interior door panel sort of like this but with fibreglass obviously:

Question though, do you need to do anything special with bonding the fibreglass to the interior panel or will it just stick?

[MLM 57]

Give it a go, as 3pedals says its not that hard. I did one years ago for a 1500w 15 in a corolla, ended up hardly impacting on boot space and no plug or mold required. The way i did it was to buy rolls of paper masking tape and line the recess you are using taking advantage of all the nooks and crannies with a healthy perimeter. Then lay glass directly on top this. Once cured you can pull it out and trim the bucket shape you created. Takes some working and pulling to get it out but you still have some flex at this point

Then make up a mdf front panel on in my case just a ring and suspend it on dowels hot glued in place at the right position you want he sub to sit at. Then using stretchy fabric you can generate the organic shape from the ring back to the trimmed edges of the bucket. Some resin to stiffen the fabric then allows layers of fiberglass to go on top. Once cured the seam can be tackled from the inside through the sub ring. The final shape will be very strong. Finally sand and cover in the fabric/paint/carpet of your choice.

Edit: Instructions here http://www.instructables.com/id/How-to-Make-a-Fiberglass-Subwoofer-Box/#intro

Edited November 25, 2013 by MLM

[Neal 544]

Looking like an interesting sub you've got.

Found this video to be a good demo on how to do the front in fiberglass. Has a good way of producing the baffle. Second link is a youtube channel which is great for the guys ideas and techniques

http://youtu.be/G8cz_

http://www.youtube.com/user/CarAudioFabrication/videos

[jcerecke 2]

Cheers for that. I've already checked out the CAF channel quite a bit. There doesn't seem to be a huge amount of info on what I'm doing though - a no MDF build (although will probably use some for the ring). I talked to the guy from NZ Fibreglass for about 20 minutes who was really helpful too.
This is where I'm up to so far:
I took the door panel piece out and masked the entire thing up and then stuck it inside a box and threw a bunch of expanding foam on it. Tomorrow I'll set about carving it into the exact shape of the cavity and then glass over top of it. My ultimate goal would be to get enough volume to have the sub sit behind the panel completely hidden but I may have to mount the sub into the panel itself. I guess time will tell!

Measure twice, expanding foam once.

3 Hours of masking!

De-masked.

Mid-carving test fit.

Edited November 30, 2013 by jcerecke

[aja540i 1906]

Something you may want to think about is how you are going to hold that panel in once its done. I am not sure that the little spring loaded clip that normally holds it will handle the weight and vibration of a 12 inch sub!!

When i did mine i managed to get a small self contained 8" sub and amp in an aluminium housing that fitted nicely where the nokia one was, i modded the original hinge and latch so it just swings out of the way when you need to get at the battery. Its not super loud but its a shed load better than the factory one, and it has a wired remote for levels etc!

Mine is pioneer, but i saw a similar one by fusion? at supercheap a little while ago.

Good luck with the install, it will be worth it!!

[jcerecke 2]

Something you may want to think about is how you are going to hold that panel in once its done. I am not sure that the little spring loaded clip that normally holds it will handle the weight and vibration of a 12 inch sub!!

Yeah I know what you mean, I've had that on my mind too. I'm just going to have to figure it out as I go along. The existing clip is actually really big, and I was thinking I would add some spongy foam to the back of the enclosure on the outside so that you have to really push to clip it in, that way there's less room to vibrate.

Got some fibreglassing done today. I must say it was harder than I thought. Takes lots of resin to saturate the mat and then all of a sudden it starts disintegrating while you're brushing it! I've done the top and four sides, still not sure about the best way of doing the bottom. I think I'll make some extra reinforcing ribs on the door and then cover it in foil and glass that as a separate piece but then how to attach them so it's strong and airtight and still some way of getting the sub in (would love to be able to rear mount it so it's completely stealth.

Carving completed!

Foiling the mould. Removing it from the door was a bitch! I found out later if you line your object with cloth/gaffer/duct tape it's easier. I ended up pouring turps all over the masking tape in an effort to release the adhesive... it actually sort of worked except left a massive goopy mess after it. At least none of it got on the carpet!

First layer and a bit of mat is on! I'm going to run out of acetone unless I do all the rest of the fibreglassing in one go, or maybe I just buy more brushes.

UPDATE: More work

Cut the edges of the fibreglass away and removed the mould. Gave it a big sand, I got way more air bubbles than I thought! And now I'm covered in fibreglass dust because it was hot out and I didn't want to wear long sleeves/pants. Ouch!

Tin Foiled the door and then glassed it... badly. There were too many fiddly bits and the chop mat was too coarse to cope so I'm going to have to redo a lot of it, but if gives you a rough idea of how it'll turn out.

Edited December 15, 2013 by jcerecke

[jcerecke 2]

After many months of being super busy and only getting to work on this project here and there it's finally (pretty much) done!

This is a SoundStream Picasso Nano Sub - purchased off ebay for some stupidly low price compared to buying it here. 600 or 650w should match nicely with the 450w sub.

Testing the sound out with no door panel on.

Now with door panel. I'm not convinced these bolts will hold to the plastic door with hot glue (and some fibreglass on top which was already breaking off).

Completely stealth!

End result: I'm really happy with it, will be sticking in some polyfill as I didn't quite manage to get the optimal volume. Everything is a super snug fit and the door latch is actually pretty heavy duty so no rattling. If the bolts end up falling off the door panel, I'll look into mounting it to the original sub mounting points but for now it's holding fine.

Next on the fibreglassing agenda will be attacking the front doors panels for 6.5" drivers or maybe upgrading the rear downfiring drivers to some 8" peerless woofers I've got.