Today I was trying to fit a port that is not of a convienient size into a small box. After trying to use a motley collection of elbow pieces I decided what I really needed was a flexible port, and then I had an idea. Flexible rubber or plastic tubing could be easily positioned and formed into shape. Since this is a really odd approach I would like to know if anyone can think of any objections or issues with this plan. I am planning on using 1.5 ID tubing with a length of about 11 inches.
After thinking about it I have a few other issues and points. The tubing may be somewhat elastic, but with some of the bend radii I have seen flexible seems to be a relative term. What the tube will do is provide a sealed air cavity, just like a stout PVC tube. The only issue here seems to be wether the pressure wave in the cabinet will be transmitted somewhat into the port cavity via deformation of the tube. If a very felxible tube is used which will readily deform then it seems to me that the port will appear to have a much larger back end than front end, I guess I need to look into the mathematical effect of this as well as some kind of factor to cover the new effect. Does anybody have experience with cone shaped ports?
One more factor to consider
Depending on the amount of bend, the stiffness of the tube material and the diameter of the tube, there will be a deformation of the tube that will affect the passage of the wave. The change in cross-sectional area will be quite dramatic for such a small distance and that will add a compressive effect to the out-going wave and changing the load on the driver. In essence, the port will have to be an even larger diameter than originally calculated. How much? Unfortunately, I don't know how that could be determined.
For an example, look in the S bend of a bicycle frame just behind the bottom bracket (the axle for the pedal cranks). There is often a big indent just to make the metal change directions so radically.
Can you just make the port stick out?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=15722&highlight=external+port
ensen
Depending on the amount of bend, the stiffness of the tube material and the diameter of the tube, there will be a deformation of the tube that will affect the passage of the wave. The change in cross-sectional area will be quite dramatic for such a small distance and that will add a compressive effect to the out-going wave and changing the load on the driver. In essence, the port will have to be an even larger diameter than originally calculated. How much? Unfortunately, I don't know how that could be determined.
For an example, look in the S bend of a bicycle frame just behind the bottom bracket (the axle for the pedal cranks). There is often a big indent just to make the metal change directions so radically.
Can you just make the port stick out?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=15722&highlight=external+port
ensen- Status
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