I designed a TL subwoofer and am in the process of building it. My concern is when it comes to stuffing the line is there a calculation I can to to determine the length of tube to be stuffed and at what density? On my last TL design I used Trial and Error. I designed to TL to be a 1/5 wave length tube assuming that if it stuffed enough to slow the air it will act like a 1/4 wave tube without the hollow sound from an unstuffed tube.
Stuff the entire tube, and no, it doesn't add enough to the effective length to amount to anything significant. Density depends on the material used.
hmmz.
i'm not very much into TL's.
i was just thinking: isn't it better not to stuff the cabinet, as then you know the exact volume and stuff? when you stuff, everything changes, without you knowing how and how much...
please say so when i'm wrong
i'm not very much into TL's.
i was just thinking: isn't it better not to stuff the cabinet, as then you know the exact volume and stuff? when you stuff, everything changes, without you knowing how and how much...
please say so when i'm wrong
TLs naturally have all sorts of resonant modes within the pipe that totally ruins the response unless you damp them out with stuffing. So do other alignments as well, but the long pipe of a TL makes them even more subject to resonances. Stuffing supresses midrange reflections back to the cone that mess up the midrange and also keep midrange from exiting the line terminus.
Thanks Bill that made sense. I have made a TL using the stuffed 1/5 theory that sounds pretty good but now I think I will make the full 1/4 wave and transfer the drivers from one speaker to the new cabinet and listen to see how much of a difference there is in sound. I am using dacron fiber to fill the tubes. Someone suggested that I would be better off with lambs wool?
Wool is a usable fiber but isn't any better than others. While the density required varies with the fiber used the end result isn't significantly different.
Wool requires some sort of support, like netting or dowel rods, to keep it from settling to the bottom of the enclosure.
A better choice than wool would be Acousta-Stuf, sold by Parts Express (Catalog # 260-317). It works much better in TL systems.
A better choice than wool would be Acousta-Stuf, sold by Parts Express (Catalog # 260-317). It works much better in TL systems.
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