I have a subwoofer box with net internal volume of 6ft3. Im going to use (4) 6in aero ports. How long do they have to be for 35hz tuning? ty?

Its a simple rectangular box for (4) 10in drivers. Ive tried to use online calculators but their numbers make no sense, exp 12volt calculator said for a 6in diameter and box vol of 6 cu ft, tuned to 35hz the port length should be 5.97inches. There's no way thats right.  Other online calculators give equally nonsensical calculations. Digital Designs said for a 35-40Hz I need 96 sq inch vent 22in long. Since Im going to use aeroports ie pvc pipes im having a hard time figuring it out. Thank you for your help. 

1 Answer

  • 1 month ago

    The volume of the box has its resonant frequency. The speakers have their operating range. The port is a function of the total cone area. If you want the system to be resonant at 35  Hz, the port length should be proportional to 35Hz- not the entire wavelength, but a function of it. The12volt worked this out. Regardless, though, that tuning is where the efficiency is at maximum, but the curve is an increase of amplitude to that point and roll off after it. 35 Hz will  be where it plays loudest, but the system gives out what the speakers produce. It won't be that critical though, since your music covers much more range than just 35Hz. Lets see how many thumbs downs the troll gives for this, without also providing any further information. However, If any of my answer is wrong, I will appreciate better information.

Still have questions? Get your answers by asking now.