how to figure out correct size box for sub?

[dman1049]

i cant go by specs of the sub cause its been modified. it can take 1500 rms instead of 600rms so how much larger should i make the box? specs on 600rms are 1.75 ft^3 ported tuned to 30 Hz -- F3 of 26 Hz

* Tune higher and use a smaller box for more SPL oriented setup (Use 1 - 1.5 cubes)

* Enclosure can be as big as 2.25 ft^3 with lower power levels

1.00 ft^3 sealed -- F3 of 44 Hz

* For SQ and space limited applications.

id like to go vented box but i dunno how big to make it.

[bassl0va]

How big is the speaker, and what model and brand is it?

[dman1049]

How big is the speaker, and what model and brand is it?

its sundown audios sa12. those specs were for the sub at 600rms the things that have been done to the sub allow for 1500 rms clean signal.

[bassl0va]

2.25 cubes, tuned between 32-35hz should work fine.

The spider is probably tighter and it has a better coil, so just use the bigger limit.

[dman1049]

how do i properly tune a slot ported box. my last box i built was a round port it had a 3inch diameter and i had port noise. id like to so a slot port and try to eliminate that issue.