1. ## Help with box plans

Hey all, Im about to build a box and I just wanted a second opinion on my layout and what I should be expecting.

Sub: DD9515h with 2k rms
Box: 4.17 cu ft total - .23 ft sub displacement, port displacement is unknown (HELP!!!)
Port inside Diameter: 6.75"
Port Lenght: 15" without flares 16.25 with

2. ## Re: Help with box plans

Based on the port calculator here Products Menu I should be tuned to roughly 35 hz before factoring in port displacement. Does that sound about right to you guys and can anyone calculate the port displacement for me??

I also have another question, are there any pros or cons to having a short wide port vs a long narrow one

3. ## Re: Help with box plans

Originally Posted by DDSC
Based on the port calculator here Products Menu I should be tuned to roughly 35 hz before factoring in port displacement. Does that sound about right to you guys and can anyone calculate the port displacement for me??

I also have another question, are there any pros or cons to having a short wide port vs a long narrow one
As far as the port ratio, having a short long port should not exceed a ratio of 9:1 or you will encounter port noise even if the area is still large enough. Because at the corners of a port, pressure increases dramatically due to boundary effects. The more "square" the port, the better acoustical output in regards to minimal distortion and timbre.

4. ## Re: Help with box plans

Originally Posted by DDSC
Hey all, Im about to build a box and I just wanted a second opinion on my layout and what I should be expecting.

Sub: DD9515h with 2k rms
Box: 4.17 cu ft total - .23 ft sub displacement, port displacement is unknown (HELP!!!)
Port inside Diameter: 6.75"
Port Lenght: 15" without flares 16.25 with
What port is 6.75"?
If I did the math correct, the port displacement is .625 cf without the flares.

Any idea what this should be tuned to? Have you built many boxes before? I can help if needed.

5. ## Re: Help with box plans

Originally Posted by duanebro
What port is 6.75"?
If I did the math correct, the port displacement is .625 cf without the flares.

Any idea what this should be tuned to? Have you built many boxes before? I can help if needed.
Its a port from an old kicker box I had laying around, tuning should be around 37 hz

6. ## Re: Help with box plans

Do you have a design yet? Are you building this yourself? I think you should try to make the box bigger and use a different port. That is just to small for the sub. DD recommends 70sqin of port and you have 36! It looks like two of the ports would work, but they would need to be much longer. I'd look into a slot port myself, and try to make the box bigger. You have a super sub - put it in a super box.

Duane

7. ## Re: Help with box plans

Problem is I dont have super trunk space so this is what I will be working with until I can glass a box in

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