I decided that the speakers in the car no longer cut it for low range response so I made it my mission to improve the sound, without wasting what little space the car already has.
I chose to buy relatively cheap rear speakers because they wouldn't be required for any low end sound and to be honest I cant really tell the difference between really good quality and just decent mid range sound whilst driving. So I bought some Option Audio 6" coaxials for $99.
To power them I was convinced to get a Kicker ZX 200.2. In reality I'm not sure this was necessary (read above reason) but the salesman was good and gave me a good deal.
For the power down low I did want good quality (well relatively) so I ordered a Polk Audio db104 dvc, which I also got for a very good price. I decided on a 10" sub because I didn't need it too loud. To power the sub I bought a Kicker ZX300.1 (2 ohm stable) which has some nice features that I will go into later.
I did all the wiring early on but I won't go into too much detail, just a few pictures:
While I was waiting for the sub to arrive I fiddled with the bass controller that came with the sub amp (this was the feature mentioned earlier):
As it came:
The circuitry out and attached to the console "pop outs":
View of completed controller sitting neatly in the centre console:
Now onto the fibreglassing.
I followed a lot of steps from mOnkey's thread (
DIY – 5th BB6 Fiberglass Subwoofer box.), so instead of going into detail about all the steps i will just show pictures of what i did, with a some descriptions. Note: Dad got a little exited about glassing again so he did a lot of the work. It was my first time.
Starting with an empty boot:
All taped up:
This is where i did mine a little bit different, instead of marking the outline of the shape around the desired volume, I marked the shape that I thought would fill the best space, then I would later build outward to achieve the desired volume:
Painting on the PVA (release agent):
Once the PVA had dried enough so the first layer wouldn't slip off, we started layering up. First layer:
About 3 layers all round:
Popped out and adding more layers:
Once we had done around 5 layers all round (more in the flat and weak places) we let it set.
Cleaned up and test fit:
This is where I utilized the wonder of technology. I had decided all along to make the box ported. Before I had even started making the box I was fiddling around the WinSD. I plugged in the theil/small parameters of the sub and with a box size of around 25 litres (what would neatly fit in the space), a ported box was always going to be better, it was just a matter of fitting the large port in. So jamming a 25L garbage bag in the space gave me an approximation for how far out the sub ring would have to come. The exact shape wasn't important because I was going to measure the volume and adjust the port length appropriately. The box is tuned to about 33Hz. Why? this seemed to give the best looking response curve.
The speaker ring in:
This is how I measured the volume:
Wrapped in glad wrap:
We then filled it up with packing peanuts with a measuring jug:
It came to about 28L but we added a few litres to compensate for the port sticking out. Combined with the 2.1L of sub displacement and the displacement of the 45cm port, the volume came to around 25L. Good guess! By the way I decided to use 45cm of 75mm (inner diameter) port because this was the smallest diameter I could go without producing too high a air velocity.
Now that I had confirmed the volume, I could cut the right length of port. This length had to include the 45 degree bend so this meant messing around with the tape measure, putting it through the joint and measuring what had to be on each side. We also had to flare the end of the port, this was done by heating it with a blowtorch and pushing it over a metal bowl. Messy but i wasn't too worried because it was only going to be covered in fibreglass.
This is the finished port being siliconed in place. We also plugged some holes we made trying to drill in the wooden supports:
The next step was to wrap the box in material. For this we used some of mums shirt material:
The material had to be stapled down on the ring on the side closest to the port because it was lifting off:
Don't mind the fold, it was impossible to get rid of.
This is how we pulled the material tight... Stitching!
The cloth was then soaked in resin:
Which was allowed to dry, and once dry the excess cloth was removed:
That fold that we were worried about before was actually a really strong point even with just resin on it.
And one layer of fiberglass was stuck down for strength, then test fitted:
Here you can see that the port conveniently fires strait toward the cabin (i have no idea if this makes a difference I just thought it was a cool coincidence):
I forgot to take photos of adding the rest of the layers but i'm sure you get the gist. Here is the fully glassed box with terminals and foam seal:
Linear Mode
