Mazda 3 SQ Build: fiberglassing again...HAT, ARC, TC, and more

very impressive build. i wish i was a master craftsman like yourself.

nice execution. you took the time to ensure everything was solid.

I am currently planning on door panel modifications - just deciding how much to cut out, what i want the end result to look like, and if i want to paint/treat the entire lower half of the panel or not.

did you create a seal between the panel and the door to prevent air/sound from getting behind the panel?

have you determined the lowest point the 3's can play with the airspace they see?

i agree a tweeter is not necessary with that position and aiming. funny how the air vents are just below the apillar pods yet the same size...

nice work overall. thanks for sharing the build pics! this is a 5* thread.

im curious on the holes drilled into the panels and the pods...... im guessing to ensure an extra hold to make sure the resin soaks in and bonds to the plastic?

resin and filler doesn't soak into plastic at all. Doesn't stick to it very well either. The holes provide places for resin and filler to fill in and provide a physical "lock" for the filler/resin to hold onto the plastic. Basically when the resin/filler fills in the holes and cures. It becomes like a rivet holding the pieces together.

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Originally Posted by ramos

resin and filler doesn't soak into plastic at all. Doesn't stick to it very well either. The holes provide places for resin and filler to fill in and provide a physical "lock" for the filler/resin to hold onto the plastic. Basically when the resin/filler fills in the holes and cures. It becomes like a rivet holding the pieces together.

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Can't say I've seen anyone do this before, but it is very smart. I guess I may have to use this method if/when I next fiberglass upon plastic.

Thanks for the tip!

Nice work looks very clean.

It takes some balls to hack into your door panels like that, they came out nice!

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Originally Posted by keep_hope_alive

nice execution. you took the time to ensure everything was solid.

I am currently planning on door panel modifications - just deciding how much to cut out, what i want the end result to look like, and if i want to paint/treat the entire lower half of the panel or not.

did you create a seal between the panel and the door to prevent air/sound from getting behind the panel?

have you determined the lowest point the 3's can play with the airspace they see?

i agree a tweeter is not necessary with that position and aiming. funny how the air vents are just below the apillar pods yet the same size...

nice work overall. thanks for sharing the build pics! this is a 5* thread.

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Good questions. First, no I have not yet created a seal betwen the driver and the back of the door card. I plan to use some CCF (closed cell foam) to accomplish this.
As for the 3" widebanders, I went by the recommended airspace requirements and kept them around 0.5 liter each sealed. As for crossover frequency selection, I wanted to kep them above 350hz as their distortion profile shows that they have significantly rising distortion below 300hz. If they were installed IB or in a larger enclosure they would need an even higher cutoff to prevetn over excursion (they only have I believe 0.5mm xmax).

Thanks for the compliments ;)

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Originally Posted by redrider

im curious on the holes drilled into the panels and the pods...... im guessing to ensure an extra hold to make sure the resin soaks in and bonds to the plastic?

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Ramos' answer below explains it well. The holes help to create a bond to the panel.

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Originally Posted by ramos

resin and filler doesn't soak into plastic at all. Doesn't stick to it very well either. The holes provide places for resin and filler to fill in and provide a physical "lock" for the filler/resin to hold onto the plastic. Basically when the resin/filler fills in the holes and cures. It becomes like a rivet holding the pieces together.

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Originally Posted by asianinvasion21

Nice work looks very clean.

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Thank you sir :)

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Originally Posted by Beau M

It takes some balls to hack into your door panels like that, they came out nice!

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Yeah, you know you're getting into a bit of work when you attempt it, but the outcome can be very nice if you're willing to take the time neded to finish them. Thanks!

Great Job

Looks great, man! The only thing I could say would be that, if you are pushing those L8's like you need to, you are going to need MUCH more deadening on that door panel!

Absolutely amazing. Master craftsman over here :)

Also, if you make sure to push the filler through the holes and then smooth out the filler on the back side, it creates a rivet effect, further adding to the part's integrity.