Need Confirmation Please

[nugget68]

since it's so stinking cold outside and I don't have a heated garage, I'm going to try to modify a box I have now for the Sundown E8V3 I just got... box is currently sealed @ .75 cu ft. taking away the sub displacement it puts it around .65, per Sundown website ported this sub should be tuned to 32htz. so if I add a 3 in port @ 25in, I should be right there according to my calculations from the app I downloaded BTC... I'm just no sure I entered the values correctly... a screen shot is below... I don't know of the port displacement is calculated on that app in the final values, or if it just gives me the displacement values and then I have to subtract that value from the box displacement...

edit... also, in order to get the 25 inches, I'll have to use two 90° elbows... will that effect tuning?

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[Boominburban 10+ year member]

you still need to take away the sub displacement from the .65 after the port displacement ...

 

[nugget68]

you still need to take away the sub displacement from the .65 after the port displacement ...

OK, so in that program, the "desired net volume" is what it is calculating with just the port then right?

 

[Boominburban 10+ year member]

YES,

It looks to me, on that app, you need to have your total net volume, including the sub displacement included in that figure.

right now you have a total of .78 cuft. which is just your enclosure minus the port area(.13cuft) for a total net of .65

if you know your box is .75 max right now, empty... you need to take that and subract your sub displacement to see what your starting net volume is.

You could always run your port external too, if you need the volume in the box ....

 

[nugget68]

well I decided to just go ahead and build the Sundown spec ported enclosure from their website... sounds great, especially for a small sub... going to wrap it in vinyl...