[thymej]

I want a Qtc of .577 (or .6 if I it does not make much deference compared to .577) and use the Stryke AV15, but I don’t know what box size to use because the formula, the Stryke web site suggested sealed box size, and WinISP pro all have deferent box sizes.


What box size do I use for 0.577 and 0.6? I will be using a BFD for flattening the room for the sub.


The sealed box formula I am using is below:


A = (Qtc/Qts)^2-1

Vd = Vas/A


Example, for a Q of 0.577 I get these results:


For Qtc of .577

WinISDPro 339L

Formula 279L


For Qtc of .6

WinISDPro 264L

Formula 225L

Stryke Web Site 142L


Help!


ThymeJ

 

[bpape]

I'd call Stryke and verify their number. Who better to know than the driver manufacturer?

 

[RayL Jr.]

You should also try UniBox - it's free too & an excellent speaker design app. The Subwoofer DIY Page - Sealed Systems: Box Calculations should help you understand & recheck the parameters entered.


I do not know why Strykes recommendation is way off, even if they deducted for a large damping-stuffing factor. Of course, if all the parameters entered are identical with the correct formula you should get the same results - there has to be a discrepancy(ies) somewhere.


The only difference should be in real world results - where you can fine-tune them. There are also some real world discrepancies for the parameters given - even with "matched drivers".




PS - since you're just dealing with entering Vas, Qts & Fs TS parameters, it shouldn't be hard to single out. Methinks Stryke could have it configured for a .707 Q (or similar) which is more "common". IMO - I like your choice of .577-.6.


Also UniBox requires Excel spreadsheet program. I don't know if you can use OpenOffice - I go into some detail about that in my Audio/video data website.


There's also A LOT of useful information at the Adire Audio Tech Central website.