Reconing from 12's to 18's

[Robert.Metzel 4]

Before my son was born, I was running 18's and I really miss the output of that setup. So I am thinking of sending in my 12's to get re-coned as 18's, or if its not to hard, just doing the re-cone myself. Yes, I am tempted to off load the two 12"s and just get a 18' xcon or BTL, but with hardly any more power, and 1/2 the cone area, this setup should be louder theoretically.

Secondly, I am not a box designer at all and I am completely lost as to what works and doesn't. This is a daily setup. I don't compete.

Using RE's Calculator just as a ref, it looks like the max volume I am able to get is around 13.5 cubes before displacement. That is leaving a bit of space between the cargo hatch and port. Also leaving room for me to see out the back window. But, I have never heard a setup that fires up and ports up. Any feed back on that in an SUV? Doing it the latter way will let me squeeze box to about 15 cubes before any displacement. Plan would be 30hz tuning. I would use a double baffle and dowel rods for bracing. 6-1" rods total. 2 top to bottom, 2 front to back, and 2 side to side. Or is that over kill?

So questions I have are:

1. Fire up and port up going to sound like ass or diminish output on the meter or ears? ( Don't compete but still like to get metered for fun )

2. Am I better off sending it in for the re-cone since the basket and everything needs to be changed?

3. I know increasing cone area should mean more output, but will it be that big of a difference on the same power level? Install dependent yes, but theoretically, the gain should be pretty significant correct?

Money is tight right now, but I am moving some funds around, booking some extra gigs, and selling some stuff that I have had in storage forever that is wasting space.

This is the box design I came up with to use just about every square inch of room I can use in the cargo area. This designing being roughly 13.5 cubes. Feel free to tell me the exact size as I am not sure how to figure it it accurately. This design leaving about 4" from the face of the box to the cargo door wall. I have ZERO clue on how to design a port for this so a bit of help there would be greatly appreciated too! The bigger box would be about a 1/2" to 1" off the door and porting up, but again, no clue on the port design. Add 3" to the depth if you are feeling port design generosity! lol 23" as total height and the box about 3" over the back head rests, but I could go 25" if it was an absolute must. Any higher and I totally lose my visibility out the back. 25" would be roughly 14.9 porting back & 16.7 porting up before displacement.

Thoughts from all you guru's please!

Front: The 5.5" is about an 1/8" over the top of the wheel well. Width on bottom and top are 1/8" gap on each side of the plastic.

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