Question on box building

[Spencer Good]

I'm using Torres calculator, and due to new size restraints I am having to work it down from 4cf per sub to 3cf per sub. I'm trying to tune her at 35hz, and if I have it set to 3 common port walls with 20" length, would this be an L port and each actual piece of the port would be 20" long? First time box builder, apologies for dumb question. Trying to work it up in sketchup and that part has me a little stumped.

[Spencer Good]

Like, i'm trying to figure out if this is correct.

[LZTYBRN]

Well first, the width across the top needs also to be 5".

And an L port in that box can't really be 20". It has to be at least 22.75", or less than 17.75".

When measureing the port length, you measure down the middle and add the front-to-back length to the left-to-right length.

In this case, you would add 20.25" and 8.25" to get a total port length of 28.5" (Note: these are just example dimensions)

[Spencer Good]

Well first, the width across the top needs also to be 5".

And an L port in that box can't really be 20". It has to be at least 22.75", or less than 17.75".

When measureing the port length, you measure down the middle and add the front-to-back length to the left-to-right length.

In this case, you would add 20.25" and 8.25" to get a total port length of 28.5" (Note: these are just example dimensions)

Thank you very much for the indepth help, appreciate it.