I still haven't learned a lot about tuning boxes, and normally pay someone to do it or use free box generators. I am likely going to have to build a box with the port extending outside of the box. Is this going to affect tuning?

Say i need a 18" deep port in the box. If I just move it out, 14" inside and 4" outside, will this affect tuning?

I still haven't learned a lot about tuning boxes, and normally pay someone to do it or use free box generators. I am likely going to have to build a box with the port extending outside of the box. Is this going to affect tuning?

Say i need a 18" deep port in the box. If I just move it out, 14" inside and 4" outside, will this affect tuning?

No it shouldnt since it is still the same length as the port needed, you will just have to make sure that you subtract how much of the port that is in the enclosure to have the accurate internal enclosure specs to get the port tuned where it needs to be.