After several attempts by my wife, a deer, and f_____en UPS to destroy my crazy system plans I've finally made it to the box building phase.

If someone has the time I'd like them to double check my findings here.

I am designing two separated boxes for 2-Planet Audio FU 15-4's run parallel
I have done several box simulations with both Bassbox Pro 6 and WinISD and have come up with a best of 4.3cu.ft(Vb) tuned to 35hz.


Here is the spec. sheet.


I tried running PA's recomended boxes with poor results.(listed on bottom of specs. sheet)

 

hm. I like the shape of the curve but are you sure the box isn't too big? Does that program do excursion modelling? I ask because of the flat spot from 35hz to 65hz. That's often a tell tale that you've maxed out excursion which is usually due to an oversized enclosure. If the 4.3cuft is for each driver then it may well be too big for current generation drivers.

 

At 10.58mm peak Xmas I think you're right!



Drops only 1.5mm from the 4.3 to the recommended 3.3 at 35hz which still seems over displaced no?

 

Yes it does. Since the woofer has an Fs of a surprisingly high 39hz, your 35hz tuning is too low. Tuning below Fs is generally a no-no.

 

Even though 35hz is on the PA spec. sheet I think you're right and am working on 45hz now.

 

I ran a pair of these in my civic a couple years ago at 4.2 cufeet tuned to 35hz
It hammered had a Real 500 watts to each worked well

 

Being my FU15's have a daul spider system.
Does anyone see why I'd have a problem running them inverted?
Has anyone seen or heard an inverted stroker?

 

the spider configuration will not change anything whether they are inverted or not. you should have no problems, although i must say no to your 2nd question.

the dual spider system is simply to stiffen suspension, lower Fs, and increase mechanical power handling.