I'm wondering whether the online caculators of port dimensions for vent enclosure work for bandpass enclosure? Also, if I were to build the triangular ports on the bandpass cabinet, can I use the calculator of square ports, by considering a square as two triangles? Finally, could anybody help to suggest a reliable online ports calculator, please? As I found many websites having different formulas. Thank you in advance
I'm surprised it is not used more. Jurgen Micka did a great job creating it. Anything from bandpass to multi-tuned 4CR are possible with this on-line program. I did ask if he would release it to be a non-web based service, but he said not at this time.
It was quite a few years ago when I inquired if he could add functionality, and that was the update as you see currently. Once you figure out how to use it, it can do quite a bit.
Later,
Wolf
It was quite a few years ago when I inquired if he could add functionality, and that was the update as you see currently. Once you figure out how to use it, it can do quite a bit.
Later,
Wolf
In addition to post #3; calculate cross section of round port first then convert it into square port's, I found another comment in another thread stating that a triangular port could be calculated from a half of a square port, what do you guys think about it? Which way, round or square port area calculation first, will likely to give a closer to the real result?
And how much may be the relevant question because in other ways the shape shouldn't matter.
There isn't much data on it. It shouldn't be an issue if the port is large enough that the velocity stays reasonable.
A triangular cross-section of the same area as a circular one will have 20% more surface.
There isn't much data on it. It shouldn't be an issue if the port is large enough that the velocity stays reasonable.
A triangular cross-section of the same area as a circular one will have 20% more surface.
A vented box doesn't care what's driving it. BTW, technically, all speaker alignments are band-pass.
Anyway, according to A.B. Cohen's 1956 DIY book, need to work with area based on the pioneer's experience with bass horn terminations, so convert the pipe's CSA to whatever shape/size it equates to plus they concluded that rectangular should be limited to the short side = 1/4 WL and the other whatever length yields the pipe's CSA, which IIRC is a 1.0:1.273 ratio.
Length will be longer than round due to differing shape/end corrections, but never seen any charts and the appropriate wave equations are way beyond my basic math skills, though AkAbak may can sim them 'close enough'.
Easiest to partially insert a too long one, use putty/whatever to temporarily seal the joint and keep shortening it as required like I did for most of my building 'career'.
GM
Is the port diameter important? I have planned to build my speaker with triangular ports. Yet, the port area is limited by the cabinet dimension. My friend, who is professional in building car subwoofer, said it isn’t important. Many of his designs had the port diameter or port area for non-circular ports fixed because of the beauty. And he often played with the port length instead. He suggested that the port size be concern for only not to generate turbulence, it is simply keep it as big as possible or at least big enough. This is the only main concern. Is his statement true? Also, what will happen if the port size is too big?
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