First time ported box build - Optimum M/s vs volume vs tune questions

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Second post here and I'll keep it short until tomorrow when I have more time. Putting together a system for my sister, going in a 2018 Rav4 daily driver.

 

Equipment:

 

Pioneer MVH-1400NEX

Machete MA-1500.1D

12" Droppin' Hz Hotel D2

Apocalypse AAB-500.4D

Black Hydra HDC-2.25 Components

Apocalypse AP-M61SL Sylvester's

 

Box Specs:

 

Slot Ported

2.74 Gross

1.75 Net

Tuned 39-40ish Hz

 

I have been researching a lot on figuring all this out and there are too many variables for me come to a solid conclusion. Originally was going for an Aero Port box and finally concluded it will not work for this small of a box without having a lot of external port. I have a very tight box size I am trying to stay within (originally 24x14x14) but has increased to 24x16x16 to get the slot port design where I want it. I want as much bandwidth as possible for her and I've concluded that if we can't make that happen I'll build a 1 cube sealed enclosure and be done with it.

 

List of programs I have been using:

 

WinISD

Torres

Triticum's Port Area Calculator

Flare-It

PSP Calculator

Ultimate Car Audio App

DBDynamix L-Slot Calculator

Carstereo.com Calculator

 

My Dilemma:

 

This might not come out right but here goes....When designing the box size, tune and m/s and using Triticums calc to help determine in>2 of port per ft>3 I cannot for the life of me get all three parameters to stay in line with one another. An example: I'll start with a box size of 24x14x14, all displacements I know and start figuring out porting. Once I get porting tune where I want it I will adjust box size to get my net where I want it. Then by making that adjustment my port area per ft>3 is way too low, so I will adjust port to compensate and then my net volume drops so I'll bump box size up and now my tune isn't where I want it. Am I going crazy, doing something wrong or is it a fact of life that you cannot ever have all three parameter "optimal" ?

 

I also have been experiencing slight variations (as to be expected) withint Torres, WinISD, UCAA and DBDynamix Calc. I could understand a few .04 or .06 here and there but I am talking about 2-3 hz differences or .10 cubes of volume differences and sometimes port length differences of several inches. SO all that said can someone steer me in the mentally sane direction...PLEASE!

 

Last but not least:

 

I finally found parameters that I think will produce a good box and modeled it up in CAD tonight.

 

 

I have a question about measuring port length and acceptable port walls. In the picture below I have my main port and then added a small 4" long section. Is that small section ok or should the port be designed differently?

 

 

The final box design below you'll notice I have larger than 3" from the left wall to the end of the port. Is this ok to do or does the end need to be 3" as the rest of the port is? As well if this is ok do you still measure out to the middle of that open area and down? The dotted line is the area I am measuring for the port (32.75 per Torres screenshot above)