I have a DD 3512 d4 in a 1.9 cf box with a 4" round x 10.5" deep port. The port noise is horrible. I have rounded the edges, but no change. Any idea's?

 

2.25 cubic feet with a 6" aero port would be optimum

 

Thank you for the responces.

@ 2.25 cubes, how deep of a 6" port would you suggest? If I keep it at 1.9 feet, how long would the port be?

We have a fantastic calculator for slots, but round ports...

 

What frequency are you trying to tune to? You could use the 12volt site for your calculations.

 

try the larger enclosure first (2.25 cubic feet) with the 4" port. if you want to determine the length of port for a desired tuning, i like to use this website:

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are you using a homemade aeroport (eg PVC pipe) or a machine aeroport? I have noticed thru personal experience that homemade ones will create more port noise than machined ones

if this all doesn't work, then more port area is needed.

 

Thank you for all of the help. It has given me more options.

The port calculation link told me that the port that I was using would be fine, tuned to 36.7 hertz. I rounded the hell out of it too. I then took a 6" port and stuck it on top of the opening to provide a horn effect on top of the original port. It's made a huge difference. I just need to figure out a way to keep it in place.