🚀 go-pugleaf

cyberF@siscor.bibnal.edu.ar wrote:
> 
> 1- about Enclosure Volume:
> Program give me a optimun volume acording to speaker specifications,
> question is. Volume filled by fiberglass that covers inside walls of box,
> must be added to software suggested volume, or not?
> 
The Fiberglass occupies near zero volume.  It looks like a lot but think
of the mass...it is GLASS.  As far as the programming is concerned, make
no adjustments for the volume of the fiberglass.

> 2-about Tuning Duct:
> Program determines duct parameters in terms of diameter and length
> acording to box volume (Vb) and box frecuency (Fb); question is:
> This given length includes the box front panel thickness, or it refers
> exclusivelly to the deep inside the box? in other words, if  suggested
> length is 3 inches and MDF thickness is 1 inch, the duct must go 2
> or 3 inches inside the box internal face?
> 
The duct length is measured from the inside surface from one end to the
other.  If the duct is to be 3 inches long, think of cutting a three
inch long tube and insert it into a mating faceboard hole.  The outside
edge of the tube will be flush with the outside face of the speaker
box.

GregVishey <GregVishey@prodigy.net> writes:
>cyberF@siscor.bibnal.edu.ar wrote:
>> 1- about Enclosure Volume:
>> Program give me a optimun volume acording to speaker specifications,
>> question is. Volume filled by fiberglass that covers inside walls of box,
>> must be added to software suggested volume, or not?
>> 
>The Fiberglass occupies near zero volume.  It looks like a lot but think
>of the mass...it is GLASS.  As far as the programming is concerned, make
>no adjustments for the volume of the fiberglass.

Er...pardon?  The amount of fiberglass used inside the enclosure will 
definitely make a difference in the alignment of the system.  (But yes, the 
occupied volume of the fiberglass is relatively small and insignificant...it 
is the action of the fibrous tangle on soundwaves that's important.)  A 
heavily filled box can add as much as 10% to the "effective" volume of the 
enclosure, which should be taken into consideration when designing.  For 
example:  You need 1cuft total.  Your driver takes up, say, 60cuin.  The port 
another 40cuin.  You plan on stuffing heavily (which isn't always the best 
idea).  Then your actual required volume is [ (1cuft = 1728cuin ) plus 60 cuin 
plus 40cuin = 1828cuin ] less 10%, or 1645cuin (0.95cuft).  Granted this isn't 
much, but it's worthwhile trying to take the stuffing into account. 

I base the 10% number on common practice of layering at least three walls with 
fiberglass.  This is a fairly simple method of thinking about the effects of 
stuffing, and doesn't take into account several other factors, but it is 
useful...

Cheers!
Todd Jenkins
Project Engineer - EV/Altec Pro
The opinions expressed herein do not represent those of my employer.