Ok.. the mission if you choose to accept it is to build custom door pods to house 6.5" mid bass drivers that will blend in with the original door card.
Step 1: Using a dry board marker.. sketch out the shape of the build.
Step 2: Strip the door card down as much as you can and mask of the area where you will need to fibreglass. Transfer your original sketch lines back on the masking tape so you know how much to cover.
Step 3: Lay up your fibreglass.. ensuring you over lap your final required area so you have extra you can trim back. This needs to be fairly strong so 3-4 layers are needed.. each layer should be applied before the previous layer has fully cured for max strength (about 10mins between layers is fine).
Make sure there are no air bubbles between the layers as this will weaken the work. Dab them out with a brush.
Step 4: Leave to cure atleast 24hours. If you disturb it too soon, it will warp and wont fit correctly. Once cured, prise the work away from the door card and clean up as much of the tape as you can.
Step 5: Cut out the rough shape of your build.. leaving a little extra for shaping/trimming to suit.
Step 6: If your door bin is split into two parts, cut them in half one side of the join. When complete.. you will still have half a useable door bin. If there is no seperator, just make one from a bit of MDF like shown below.
Step 7: Place the usable half of the door bin back in position and trim your build to fit.
Step 8: Cut out a seperator from a bit of 18mm mdf. This is easily done by standing the door bin on its end and drawing round the inside edge, then doing the same thing with the fibreglass back panel you have made.
Step 9: Test fit the first half of the door pod back.
Step 10: Key up the inside of the door pocket to allow better adhesion of glue/fibreglass later.. this can be done with sand paper or just scratch it with a knife.
Step 11: tempoarily fix the front half of the door pocket to the fibreglass with some sort of glue (doesnt have to be strong). I have used no more nails as I have loads of the stuff. Hot glue is also fine.
Step 12: Once set.. you need to do the final strong bond. This is done by mixing up some fibreglass resin.. then tear up some bits of fibreglass mat and mix into the resin making sort of a runny fibreglass mix. Pour into the build and angle and support the pod so that the mixture rests over the join. Leave to cure for 24 hours.. and repeat for all edges (both sides and bottom.
Step 13: Draw out your baffle ring. Here you can see three rings. Inner most ring is your cutout diameter for your speakers motor structure. Ring 2 is your speakers overall diameter. This will give you the rebate diameter to allow your speaker to sit flush, and the final ring is your finished diameter for the ring about 1cm bigger all the way round to give some extra strength. 18mm MDF is best here to allow you to flush mount the speaker.
Step 14: Cut out your baffle rings using a router/jigsaw with a compass attachment. A router is better as it will give a cleaner cut and allow you to cut the rebate for flush mounting the speaker.
Cut the rebate first to a depth equal to half the thickness of the material. Next Cut the overall diameter.. and lastly the inner speaker cut out. Then test fit your speaker.
Step15: Cut a hole in the door pocket to allow for the speaker to sit in the required position. If you need to.. clean up the areas where you will attach the stand-offs for the baffle ring.
Step16: Glue your stand-offs to the baffle ring. The length and position of the stand-offs are determined by the required baffle angle.
Step 17: Using a router.. round of the top edge of the rings to give a nicer finish and also to increase the adhesion area for the covering later. This could of been done at step 14 but I forgot
Step 18: attach your baffle to the rest of the build. I have used hot glue for a quick fix that can be reveresed if needed fairly easily.
Step 19: Stretch your shaping material over your build and attach behind using hot glue. Your material needs to be stretchy and thick so it can hold lots of resin. I have used fleece.
Pull the material tighter or give it some slack around certain areas until it gives you a shape you are happy with.
Step 20: ensure both builds look as similar as you can get them.
Step 21: cover in resin and allow to cure for 24 hours. Get on as much resin as possible.. the material has to be soaked through to the other side. Especialy around the edge of the baffle and the edge of the build as this will provide the adhesion needed on the joins. Apply a layer and give the resin a few mins to soak in.. then repeat until it cant take anymore. Once cured.. assess the strength of the pod to see if you need to add any additional fibreglass layers for strength. As I used thick material, and this was just for a mid bass driver.. I decided I didnt need too as the build was strong enough. For a sub box, I would of added another 4 layers or so of fibreglass on top while the fleece was still wet.
Step 22: The build isnt going to sit nicely onto your door card with the over stretched fleece on the back so that all needs to be cleaned up.
Step 23: trim back as much of the un resined fleece as you can.
Step 24. Grind/cut back the remaining cured over hang back to the base plate so that the build can sit back onto the door card. I used a conbination of a router with a flushing bit, and a dremel and other grinding tools to clean this all off. Once you have done this.. you will need to strengthen the join of the top edges from inside. Do this using the same method as step 12.
Step 25: Cut out the speaker hole to the edge of the baffle rebate. This was done using a sharp knife to remove un resined material.. then a combination of a dremel and a router with a flushing bit. At this point.. the basic build is complete and ready for finishing to suit your final trim method. If you are going to cover them in material.. you should be able to get away with a light sand with a power sander to remove any lumps and ridges.. and minmal filler work.
If you want to paint, you will have to skim on filler and sand it smooth working your way through from coarse to fine grit papers until you get a perfect surface. The trick here is to go easy on the filler. Dont dollop on a 5mm thick layer then spend days sanding it back.. load up your spreader with a small amount and with firm pressure.. scrape it over the surface.. only leaving filler behind in the pits of the rough surface.. lightly sand with coarse paper.. and repeat.. but between each filling layer, change your sand paper to a finer grit. in 3-4 layers, you will have a perfectly smooth build which can be finished of with filer primer and a light sand with wet and dry.. before painting.
Amit
How to build custom door builds (Pic heavy)
