Internal Volume and Port tunning+Area

[JuiceTin]

I have 2 Resilient Sounds RS 15s entry level 500w subs currently.
I'm lost on what the internal volume should. Plus the what i should tune the port to and also the area of port.
want it to be a slot on the front panel.
I'm using sub box pro and here's what i got so far box
Let me know what y'all think i should make these values

Click to read more...

 

[Doxquzme Premium Member]

Not sure what the confusion is.
Outside dimensions
42.00" × 18.00" × 20.65"
Wood is 3/4"
The internal volume (after woofer and port displacement is 5 cu feet
The tuning is at 33hz
The port opening needs to equal 100 inches any combination that equals that. 6.06" × 16.50" (=99.99) is based on the dimensions of the box designed.
37.26" is how long the port is. Measured from the center line of the p[ort front to back of the port.
Cut sheet is the rest:

Top / Bottom

42.00" × 20.65"

2

Front

35.19" × 16.50"

1

Rear

42.00" × 16.50"

1

Left

19.15" × 16.50"

1

Right

19.90" × 16.50"

1

Port

13.09" × 16.50"

1

Port

16.61" × 16.50"

1

the program doesn't understand that someone has to actually cut those measurements. What you need to concentrate on is this.

The external volume is 9 cubic feet, the gross internal volume (before the port and the subs) is 7.4 cubic feet. , the internal volume after the port (total port displacement is 2.15 cubic feet or 3726 cubic inches.) and the subwoofer displacement is 5 cubic feet - maintain this in any shape you can make fit in the area that the sub will go.


You just need to make the box according to that formula.
Internal prior to deducting the port is 7.4, the area that the port takes up is 2.15 cubic feet and the minus the sub displacement, equals the 5 cu ft.

 

[Doxquzme Premium Member]

 

[JuiceTin]

Not sure what the confusion is.
Outside dimensions
42.00" × 18.00" × 20.65"
Wood is 3/4"
The internal volume (after woofer and port displacement is 5 cu feet
The tuning is at 33hz
The port opening needs to equal 100 inches any combination that equals that. 6.06" × 16.50" (=99.99) is based on the dimensions of the box designed.
37.26" is how long the port is. Measured from the center line of the p[ort front to back of the port.
Cut sheet is the rest:

Top / Bottom

42.00" × 20.65"

2

Front

35.19" × 16.50"

1

Rear

42.00" × 16.50"

1

Left

19.15" × 16.50"

1

Right

19.90" × 16.50"

1

Port

13.09" × 16.50"

1

Port

16.61" × 16.50"

1

the program doesn't understand that someone has to actually cut those measurements. What you need to concentrate on is this.

The external volume is 9 cubic feet, the gross internal volume (before the port and the subs) is 7.4 cubic feet. , the internal volume after the port (total port displacement is 2.15 cubic feet or 3726 cubic inches.) and the subwoofer displacement is 5 cubic feet - maintain this in any shape you can make fit in the area that the sub will go.


You just need to make the box according to that formula.
Internal prior to deducting the port is 7.4, the area that the port takes up is 2.15 cubic feet and the minus the sub displacement, equals the 5 cu ft.

I was really just guessing on these values and dont know if they are are right, also the subs will be inverted.
Because I seen some people run like 7.5cubic feet and 160inch on port area

 

[Doxquzme Premium Member]

While that program is pretty neat, it assumes you know the values. I was just recapping the numbers you provided. RS recommends the following

Ported enclosure

1.75ft-2.5ft tuned @35hertz with 12-16 square inch of port area per cubic foot.
It's only going to make a box and provide the cut sheet based on those values, thos numbers change when you invert the subs as they no longer account for displacement. As for the port, the program takes the frequency that you give it and calculates that value, which you provide. Change that value, port changes too. without actually modeling the sub according to it;s T/s parameters, you can't really know. If you got the numbers from the manufacture, then they may be spot on but one cannot, or could not guess. If you don't have WinISD or some other modeling program, I'd stick to the manufacturer's recommendations or peruse the internet to see what others are doing with the same thing.

No time like the present to learn, right?