Box Modeling please help

When using win ISD to calculate boxes,, are the given air volumes and port sizes good for car use too? if not, some advice on how to model up a car box please

1. question: if i can make a very small ported box with a very long port , and very l;arge box with a small port, and achieve the same tuning frequency, how does that affect the sound


I know sealed boxes have Q factor's
i know that .707 is the best possible mix between excursion,powerhandling and spl
i know wthat a Q below .707 just begins to create a really low tuning frequency,

and above will not get full output out of the driver with as litle watts,

QUESTION, If i reach full excuring with a q of .5
and if i reach full excurtion in a box wiht a Q of 1.2

which would be louder? or would they be equal

if they would be equal,, that just means a larger sealed box increases sensitivity right? if not what does it change?

Thanks for you time, any help is apprecaited, jaden\


Do ported boxes have Q factors? to keep you from going to small wiht to big of a port, or going to big wiht to small of a port,,

is there a perfect mix?
or is it just preference,.,

thanks again
jaden
 
if you displace the same amount of air, at the same frequency with two identical drivers in different sealed boxes, yes the sound pressure should be the same.

a larger sealed box increases sensitivity at low frequencys.
a smaller sealed box increases sensitivity at higher frequencys.

Like Ron E said... do some reading on the basics. www.diysubwoofers.org has some pretty simple explinations that should be a decent start. Once you've learned a bit more you might want to check out vance dickason's "the loudspeaker cookbook" or other similar texts. Reading the help file in WinISD would probably be helpful also.

We can answer your questions, but first try and figure things out yourself... if you still need help, ask away.
 
Hi,
I find that using a piece of someone else's software gives the answers without one understanding what is going on with the technicalities.
A good read on the subject before using software tools helps a lot and I thoroughly recommend "Bullock on Boxes" - Audio Amatuer Press. This is dedicated to vented enclosures.
Chap1 Thiel Small, C2 design parameters, C3 vented design, C4 alternative alignments, C5-C9 software, C10 q&a