I need some help, comparing results WinISD vs BassBox vs WinISD Pro, why ??? - Toyota Yaris Forums

talnlnky · 12-24-2008, 05:24 PM

YES!... a fellow box modeler...

I started using ISD Pro, then got my hands on BBP 6.
TRUST BBP, ISD though fairly good, isn't as good as BBP. Though, BBP is much more technical.

On with your problem... I might get around to actually modeling this up myself... I dunno, can't promise anything. Its been awhile since i've done much box designing/modeling, but I believe the problem is the box size.

Focal is saying to go ported on that 15/16" sub with 40-60L. There are two big clues that state that the sub probably needs a bigger box tho. Check out the values for Vas, and Qts.

That Vas tends to say "decent sized box"... and generally the higher the Vas, the bigger the box you need.

The Qts kind of gives you a clue as to how big, or small of a box it needs, the lower the value, the smaller the box. Its most often used to determine what kind of box because it has to do with the suspension & movement properties... but generally the small the number the smaller the box (comparing ported to ported, and sealed to sealed of course). That Qts shows your sub as being boarderline ported/sealed box optimized. If you had a value closer to say .30-.35 i'd be more willing to believe that your sub is meant for small 40-60L boxes.

SO!.... what I want you to do, is to model those boxes up again, and then change one of the boxes to 100L/FB 35, and then do another to 150L/FB 35. See what happens to the frequency response. I bet the bottom end really fills out.

If it does, let me know, and i'll explain what most likely is going on.

EDIT: when I talk about "big box" or "decent sized box" I mean relative for a 15" sub. obviously any box for a 15" will be big, even a sealed box.

12-24-2008, 05:24 PM	#2
talnlnky Audio Junky Drives: 08 liftback Join Date: Oct 2008 Location: Spokane, Wa Posts: 1,412	YES!... a fellow box modeler... I started using ISD Pro, then got my hands on BBP 6. TRUST BBP, ISD though fairly good, isn't as good as BBP. Though, BBP is much more technical. On with your problem... I might get around to actually modeling this up myself... I dunno, can't promise anything. Its been awhile since i've done much box designing/modeling, but I believe the problem is the box size. Focal is saying to go ported on that 15/16" sub with 40-60L. There are two big clues that state that the sub probably needs a bigger box tho. Check out the values for Vas, and Qts. That Vas tends to say "decent sized box"... and generally the higher the Vas, the bigger the box you need. The Qts kind of gives you a clue as to how big, or small of a box it needs, the lower the value, the smaller the box. Its most often used to determine what kind of box because it has to do with the suspension & movement properties... but generally the small the number the smaller the box (comparing ported to ported, and sealed to sealed of course). That Qts shows your sub as being boarderline ported/sealed box optimized. If you had a value closer to say .30-.35 i'd be more willing to believe that your sub is meant for small 40-60L boxes. SO!.... what I want you to do, is to model those boxes up again, and then change one of the boxes to 100L/FB 35, and then do another to 150L/FB 35. See what happens to the frequency response. I bet the bottom end really fills out. If it does, let me know, and i'll explain what most likely is going on. EDIT: when I talk about "big box" or "decent sized box" I mean relative for a 15" sub. obviously any box for a 15" will be big, even a sealed box. __________________