MrCabinetry

Well, BBP 6 does calculate a slot port accurately given the way the program does model it within the Box Volume Displaced by the Port parameters. However, within those parameters, it has to be specified what the thickiness of the material being used noted by input " B ". The Box Volume Displaced by the Port parameters are not making any assumptions here, they are performing the function properly based on the manner which the program was written to calculate either a round or slot port not to include any part of the enclosure itself. So, like a round port which is calculated to lenght based on the volume, diameter & tuning frequency, a slot port is calculated in the same manner as if it were a separate part installed. Now, given that the majority of the time when we design ported enclosure's using slot ports, we're going to use the top, bottom, side & back for part of the slot port walls. This leave's us with only having to determine the final port wall or walls that make up the rest of the slot port which we have to figure out their displacement which changes the parameters of the enclosure design. LB ( Lord Baccus ) asked me this question awhile back when he was trying to figure out a slot ported design in BBP 6 and his calculations were getting totally throw off because he could not understand which parameters within the program were causing the conflicting issue's. Rather than trying to explain it to him, he sent me his BBP 6 design and I sent him back my BBP 6 design of the same enclosure and referenced those parameters within the program to show the errors within the formula, once he saw both designs side by side, he got it just like that. Your are totally correct, when designing slot ports within BBP 6, you have to totally zero out the parameters in the Box Volume Displaced by the Port parameters and use the Box Volume Displaced by Miscellaneous Objects to properly calculate the slot port parameters to account for both the Port Displacement and Port Wall Displacements. Granted, it's a royal PITA to calculate the slot port parameters accurately because you have to constantly re-adjust all the other parameters but I've discovered a few tweaks and using a calculator I created in EXCEL, I've reduced the amount of effort I need to apply for designing slot ported boxes in BBP 6 and in turn allow me to build enclosure's with a greater degree of satisfactory results in terms of bass response and performance once the customer recieves and installs the enclosure. We all agree that the other factors involved after the sub/enclosure are installed are going to skew the bass response/performance, none of us can deny that unknown element. Phil Woodlawn Cabinetry ( NOT KENT )

Tirefryr, While I have to agree with you about enclosure modeling programs as being wholly inaccurate as to the cheap or online programs. In my experieence using Bass Box Pro 6 given all the enclosure's that I have designed and built and delivered, BBP 6 has yet to provide any unsatisfactory comments from any of those customers. As we all know, enclosure design programs are intended to be used as a tool to at least provide within reasonable expectations of bass response and performance given all the other known factors involved that are going to effect the subwoofer/enclosure after they are installed in the vehicle.

Hey LB, Thanks for the plug here

Thought I stop by and sign up since another member referred to me within the forums.