WinISD vs. UniBox on port tuning

[dscline]

I'm putting together a ported sub. This is kind of a quick/dirty project, and the way it's going together, it's wouldn't be easy to fine tune the port once done. But WinISD and Unibox are giving me two different answers as to port length: WinISD says 11.79", and UniBox says 10.72". Everything else is the same, to the extent possible. Not a huge difference, but I'd like to be as accurate as possible. Anyone have any experiences that show one to be any more accurate than the other?

[Collo]

One of the authors of WinISD wrote a paper comparing predicted port lengths given by 10 packages.

Access the paper from this WinISD discussion thread

Whilst it doesn't list Unibox, it does show good agreement between WinISD and most of the packages listed

I've attached a partial screenshot

[dscline]

Hmmm. Someone at AVS has been getting lower real world tunings than WinISD predicts, which was starting to make me think UniBox might be right. Of course, it's certainly possible one could be high in one situation, and the other high in another. The difference only correlates to about 1hz, so it's not a huge deal either way... maybe I'll just shoot for something in between.

[moray james]

make th event 11.75 inches long. This is easier to measure with a rule and splits the difference in a dirty way. The difference in your box volume (predicted Vs actual) will be miles bigger in difference that the vent length difference you are looking at. Gets even worse if you decide to flair the vent ends. (good idea to me). Sounds like you are drinking too much cofee. It was your idea to make his quick and dirty I agree. I have seen $3500.00 speakers with vent lengths that were different by almost 3/4 of an inch. Didn't bother the manufacturer much. Sloppy and unforgiveable at that price point. Regards Moray James.