12" q box questions

[b_evans06 0]

I recently purchased a 12" Q series sub. I am installing it in a ported enclosure and I am curious to the size and tuning. After purchasing the sub I found a deal too good to pass up on an amp that is a little underpowered for the Q. It is a kicker zx750.1. It puts out between 800-900 watts rms. I see on the pinned topic at the top the recommended ported enclosure is 1.8-2.5@ 28-33hz. With 12-16 square inches of port volume. My question is should I change the box size or port area since the speaker will not be driven at full rms power? I want to get as much out of the speaker as I can with the power I have available. I thought I would ask on here instead of calling seeing as how they're such a busy company.

Another question I have is on port calculating how do I calculate to get the 12-16 square inches? Is it the widthxheightxlength?

[NDMstang65 403]

You can make the box a little on the larger side of the spectrum...because you have less power..

12-16sq inches of area is per cubic foot of volume...so if it's 2.5 cubic feet you can run a port anywhere from 30-40 square inches of vent area (width x height) then make it however long to tune it to whatever frequency you desire...

Thanks!

-Nick

[b_evans06 0]

Thanks for the explanation on the port calculating. I still don't think I fully understand. So is the 30-40 square inches the actual port opening (heightxwidth) for example 12"x3"? Or is the 30-40 square inches the total port area (heightxwidthxlength) for example 12"x3"x24"? I just made these numbers up off the top of my head so I know they may not be correct. Like I said I still don't quite understand how to calculate the port dimensions. If you could help me out I would greatly appreciate it. I am looking at 2.5 cu.ft. with a port tuning of 33hz as recommended in the pinned section at the top. If say I wanted the port to be 12" tall and 3" wide how long does it need to be? Also this is for a square slot port.