HI all ..... why is it that i am getting completely different prediction models from Isdcad WINisd and Bassbox pro 6 for a closed box with the same two drivers. I am not talking about 5 or 6 % . I set them all for golden ratio but i get 2.2 cuFT for Bassbox pro, 5.5 + and change from Winisd and 3 cuFT + for ISDcad.
I checked all the parameters and they are all the same on each programs database of that driver. Hi-Vi D10G woofer, 2 in a closed box. Is there something hidden i am missing ?
I checked all the parameters and they are all the same on each programs database of that driver. Hi-Vi D10G woofer, 2 in a closed box. Is there something hidden i am missing ?
Madmike2 said:
Depending on what assumptions you go with, you could say that for the parameters:
Fs=25
Qts=0.44
Qes=0.54
Vas=138L
All of the results below are for Qtc=0.707, and all are justifiable results - except perhaps for the ideal box, that is
Undamped ideal box
Vb=87Liters per woofer
Fc=F3=40.3Hz
Small Margolis undamped gamma=1 and Qa=10
Vb=69Liters per woofer
Fc=F3=43Hz
Small-Margolis damped gamma=1.2 Qa=5
Vb=46Liters per woofer
Fc=F3=46Hz
Benson formula (Like used in Bassbox 6+ and Unibox) lined, not stuffed, no adiabatic-isothermal assumption
Qa=20, Qp=0, Ql=20
Vb=71L per woofer
Fc=F3=43Hz
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The only way you can be certain of your model is to measure it after building a test box to see if the assumptions you used are correct. Interestingly enough, measurement at those frequencies can be difficult to interpret, and once you get out of the small-signal arena all bets are off anyway. Makes it seem amazing that anyones' boxes sound good, doesn't it?
So build your boxes somewhere between 46 and 87liters per woofer and you should be happy
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