2 10" Sonotubes 2 SQ HDC3 18's (Input on Round Port Area Please)

[Joe X]

The calculator is from a round port manufacturer and you should no be concerned about it's accuracy, the output is going to be determined by your box design, electrical and general system setup.

[BamaBoy334]

i get the same thing from the all programs, with roughly 1-2 inches to spare. itll tell you legth yea but wont tell if its a good decision ya kno?

[Joe X]

If you need to tweak your tuning easily round ports are the way to go other than that, as long as you have enough port area both slots or round ports can do the job.

Efficiency is lost in other things too that should be considered like cancellation, flex, improper tuning, bad electrical or wiring, etc.

[BamaBoy334]

thanks for the help brother