HELP!! Question about my Sonotube subwoofer..

[morrowaudio]

Hello!

I posted this elswhere on this forum but thought it should go here..

I found this thread and decided to build my own Sonotube subwoofer, two for listening to music only...one for the left corner and one for the right corner. I want response from 17 hz to 80 hz. I have horn speakers for the upper bass, midrange and highs.

My Sonotube is 20" in diameter and 5 feet tall. My port tube is 6 inches in diameter PVC. The driver I am using is the DAYTON TIT400C-4 15" TITANIC MKIII SUBWOOFER 4 OHM's. The Fs is 19.93 Hz.

The speaker will be at the floor end and the port at the top end.

Questions:

1. How long should I make my 6 inch dioameter port tube to tune the speaker to 17 hz. I used some online calculators and it said to make them 19.8 inches long. Is this correct?

2. I am using legs on the bottom and top with another end cap above the port and below the bass driver at the bottom as seen on the ones in this thread. The question is how tall should I make the leggs to properly couple the speaker to the room? I have seen anything from 4 inches to 8 inches. I know this can effect response and need to know what would be best for the system I have chosen.

Thanks four your help! This is FUN!!!

Mike

[ThomasW]

I'm sorry but it's physically impossible for us to double check everyone's design. Doing that takes as much time as creating a design from scratch.

You'd really be better off downloading Unibox and doing a proper simulation.

The info you posted doesn't say whether your 60" includes or excludes the endcaps, so we don't know what net internal volume we're dealing with....

What I can tell you that your tube is 10.91 cu ft (gross) and a 6" port tuned to 17Hz in that size enclosure would be 33cm (13") long, so your model is close if all other things have been accounted for....