Wow, didnt realize at first I was talking to THE hornresp man

In any case, I got some deeper into the math because you asked me, and I clearly missed a lot of the 'complexities' so I will not be pursuing the math. I don't like math that much, that's why I love software like yours!

So lets aside the math, and just focus on what perplexes me the most.

'I get drastically different (and not linear) differences in output, velocity AND port length when doubling port area, but keeping tuning equal (by also changing porth length). I also dont see a mathematical trend that explains it.'

I dont have the exact numbers anymore, but I dont remember seeing any logical trend. I figure there will be one, and it could just be the actual math that was too complex for me. On the other hand, winISD didnt show this.

Could you explain me some of the factors that determine the output of the ports? And why I would get largely different results although the tuning and box volume stays the same?

I'm in the process of understanding port compressing, chuffing so I would need to know if its somehow already included in HR.

Thanks in any case for your wonderful software!