How exact must port sizes be?
The reason I as is this:
I am building a box that requires a 3" Round Port 7.6" Long.
I have converted that to a Rectangular Port with 7.065 square inches of surface area. The easiest way to get there (by my math), is a slot 1" Tall by 7.065" Long and then 7.6" Deep.
The length being 7.065 is really close to 7.0625 which would be 7 1/16. I do not know if I can be that dead-balls on accurate. Will it affect the port tuning by much to round it off to an even 7"?
KillJoy
That will be fine but remember you are going to need to add the extra surface area of the wood your going to be useing to the size of the box because the wood be it 1/2" or 3/4" is way biger than a flimsy pvc tube.
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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.
The precision of the port size depends on the tuning and the box.. often at one length very small changes in port length produce large changes in tuning frequency, but as the port gets longer, often it doesn't affect the freq. as much...
Same for the resulting response curve.. it might look identical with a port that is tuned to 25 - 35 hz.. but bump it up to 40hz and the curve suddenly gets *very* peaky.
But yea in that case 7" and 7 1/16 *will* be functionally identical.
JL Audio has an excellent tutorial on construction of slotted ports.. it might be worth a read before you start cutting wood 'eh?
https://www.jlaudio.com/tutorials/ports/index.html-------------
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