What is the best Port length?

Don't know what length your port needs to be??
In this video I go through the maths and some principles of basic ported speaker tuning, including choosing tuning frequency itself.
Timestamps:
0:00 - Introduction
0:47 - Port basics
1:58 - Choosing tuning Frequency
3:07 - Equation Examples
6:36 - Equation for port tuning
9:26 - Software - WinISD- Inputting specs
12:13 - Altering tuning and port length to fit requirements
14:26 Conclusion/Outro
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