I have a few details I was interested in having explained. The dimensions generated seemed to follow a 1 x 2 x 4 pattern, therefore, to compensate for internal displacement of physical objects inside the cabinet, such as the magnet and basket, and whatever cross-bracing is there, do you simply keep the 1/2/4 ratio and increase the dimensions until the additional volume is accounted for? Is the volume enclosed by the vent structure and inside the vent already included in the box dimension calculation, or is that another volume that must be added back into the cabinet dimension?

Can you find Zmax from mechanical parameters? Thanks for any clarification (I have more questions for another thread).

John

About finding Zmax from electro-mechanical parameters, I never really thought about it but, yes, you should be able to backsolve Zmax when other parameters are known. You might check the popular T/S modeling programs and see if any of them calculate an electrical impedance chart.

About different port shapes, I typically use cylindrical when I can, and rectangular when I can't. The PiAlign program will calculate either one. Sometimes the optimal cylindrical port is not of a size that is readily available. So when that happens I sometimes use a rectangular port. If the port is short enough, sometimes I just glue wood panels onto the baffle to build up thickness to the required port length, then drill through at the needed diameter with a hole cutter.

As for standing waves, they aren't a problem if dimensions are acoustically small. But if used to high enough frequency, then cabinet will start developing standing wave modes. The port can do this too. That's what the insulation inside is for. It's usually sufficient to cover three internal sides with R11 or R13 insulation, but larger cabinets are usually better with insulation spanning the cross-section too. Cross-braces are a convenient place to put spanning insulation like that.