well, after a few attempts i think ive cracked it :)

Step 1: Making the Mold Plugs

i'd never done this before but it turned out easy enough, the old speakers are in the pic to give an idea of the size upgrade

Step 2: Making the Molds

use beefy ply for the tongue, otherwise it will flop about

Step 3: Fiberglassing

im not going into the ins and outs on fiberglassing, its on the net ;)

the sheets were made by applying fiberglass to an old mirror, be sure to use lots of polish to release it

Step 4:

its made to split down the middle

Step 5:

dont do what i did.. leave it on the plug for a couple of days to harden fully otherwise it with deform later

Step 6: Molds Made

i used a bit of filler along the join to fill the crack..

Step 7: Missing Steps :(

im making this and realizing ive lost half the photos :( so the stages jump quite a bit, if i find the photos ill add them

but here ive used the molds to make these..
to thicken the fiberglass resin i added kiln dried sand to the mix, this makes it thicker and able to fill gaps and it sets rock hard, the tongue part is simply glassed to the rear of the moulding

Step 8:

again, essential photos missing :(
but the holder was made from 3 layers of ply and bits i had lying around and the speakers fit snuggly in the slot

be sure to dowel the layers

Step 9: Electronics

i used a nice audio board off ebay for 20 quid, its 25w rms x2 at 4ohms, so i bought my favorite dayton audio nd-91/4's these really bounce about:)
and i built in a bluetooth headset so its wireless to my phone (again with missing pictures because im useless)

Step 10: Batterys

i used batts from an old power drills with a few dead cells and made up a battery pack, these last about 6 hours at almost full volume

Step 11: Paint

the first set had gold paint, but it looked a bit much to be honest, so ive been playing with an airbrush..

the later sets had no battery monitor (didnt need it anyway)

but i did add a usb charger:)

again, sorry about the missing steps, but i think they're covered in the other bike speaker sets ive made and posted on here.

any questions just ask x