![]() ![]() port (or others equivalent) to be considered minimally acceptable here. From that result you decide if port tube has too large diameter and prefer to split it in 2 smaller tubes of equivalent area.There's another formula for that. So you solve the parenthesis first, then do square root and finally multiply by two, which gives you the vent tube internal diameter. But in case the question is how do i translate a port area into a vent tube diameter, then the formula is:ΔΆ X square root of (area divided by Pi). RE "how do I translate the "Port min dia." and "Port length" to a number of ports?" I'm not sure i understand your question. (Btw if you made a port using a whole bunch of straws, not recommended, you'd need to readjust Qp! Also if you put an unusual amount/tickness of damping material in the box then Qa may need to be revised). Typically Qa and Qp are left at standard/default number (except special situation) since most of the time absorption and port losses are so small that they can be ignored when a cab is properly designed and built. ![]() In the real world with losses QL is in the 5-10 range mostly, with 7 being sort of the middle (lower number lossy box, higher number less box losses). Unlikely to happen, pretty high number, about the number for an absolute perfect box. The QL 15 that you show in your example is way too optimistic. It may need to be adjusted a little up or down depending on circumstances. QL is box losses, its the more important of the three, and the standard used to model boxes is QL 7. Qa is absorption from the damping material in the box. If not satisfactory i change Vb (plus or minus) and repeat the tuning process until i'm satisfied. Personnaly i start with an approx Vb (an educated guess) and try by varying Fb to get response i want. To model a driver's response in a box you rather do this with box size (Vb) and/or box tuning frequency (Fb). For example, you don't normally play with Qp to improve response results and don't decide what port losses will actually be. You sure tried hard! but your normal playing field doesn't involve much Qa, Qp and QL. RE "change the "Port, Qp" to obtain a similar result as provided by the "Standard design". Doesn't mean its the preferred one when all is factored in. I think what you got in terms of "standard design" is the maximally flat response type, some softwares automatically default to max flat curve. Can't really help you with its specific functions. Not familiar with Unibox details, its user interface isn't as friendly as others. Maybe its simply picture distortion, sizing issue or Unibox stretching graph to 10hz? Slope on my graphs appears steeper, and more in line with a vented box. Strange, another reason i did my own thing. or so (typical of sealed box) but yours indicates vented box. Finally, one thing bugged me a little on your own response curve, the LF roll-off slope looked more like a 12db/oct. As for comparing, my quick modeling gives another view, even shows on first pic two response results that can be compared. I'm giving you some guidance below in that regard. Well, the optimizer is YOU sitting in the driver seat trying different software scenarios based on your needs or wish. an optimizer that would make compare the results. First, i needed to convince myself that this system could be worthwhile in view of Unibox confusing dash board info. The following question is, how do I translate the "Port min dia." and "Port length" to a number of ports? I was wondering if somebody experienced could review my approach and results and suggest improvement/optimization. Then I changed the Vb to a reasonable 150 l, and kept changing the Fb to obtain minimum of F3. Thus I first entered the calculated parameters into the "Design by Vb, Fb, and Q" and change the "Port, Qp" to obtain a similar result as provided by the "Standard design". However, the enclosure is rather large at about 178 l. That gave me parameters in the "Standard design". So, I entered "Wanted tunig peak" = 0.00 dB, and executed "Optimise Fb for wanted peak". I am also unsure, how to select the "Fb". I started modeling a bass-reflex enclosure in Unibox version 408, but I have not found any tutorials or description, what to enter into certain field, e.g., "Port" - "No of ports", "Inside Port dia", and "Port end correction" "Design by Vb, Fb, and Q" - "Port, Qp". ![]()
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