from my understanding, I believe you need to subtract the port volume from the box volume to find the net volume... so the sub(s) are seeing 5cu.ft and thats what you enter in the program.

 

Correct, you enter the port displacement. The program runs dumb but it's what you have to do. It'll also be off about 5Hz over.

 

Are you possitive about the 5Hz over? Cause I just used it to design my own box. What I did is use it with a given volume and the freq I was after and after getting the port length I just added the port displacement onto the original Box volume I used. then I crunched the numbers to get a volume that was close. And then reinput the exact volume to be prcise on the tunning.

Here it is. I was hoping someone could verify this, cause now I am worried.

http://www.icixsound.com/vb/icixnati...ges/201_53.jpg

 

yah that worried me.i dunno if its for real. my box tuned to 41 but is really 36ish hz??? damn

 

ok to all you guys that think the program is not accurate...

I'll try to understand... you tune your box to 41 Hz but in your car plays 36 the loudest??
if this is the case check your impedance curves in the program...you may be playing the impedance curve to the liking of your amplifier instead of the output peak of the enclosure since at the peak of the enclosure it has high impedance rise and your amp will put out low power


hope this helps..I have also noticed this phenomenon and been using it to my advantage... my SS-NW is actually port tuned to 71 but I am playing 67Hz...


Richard.... in the progy the box volume you enter is air volume only... port is only your port volume...your final box will be AIR VOLUME+PORT VOLUME+SUB DISPLACEMENT as Im sure the subs you are using will be aprox .25-4 cu.ft. displacement each

 

or just get termlabs oldschool box program and it does all of those calculations for you...which of course is good because as you change tuning in winisd you would constantly need to be self adjusting the box volume to compensate which would of course be a gigantic pain in the butt

 

WIN ISD does not subtract port or driver displacement for you.

 

win isd also doesn't calculate for more than one port.

 

Yeah it does, you click on the box that says number of ports.
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