Soundstream spl-170 User Manual

6 

Sealed bandpass enclosures enclose both sides of the woofer(s).  An 
airtight enclosure is built around the front and back of the woofer and 
one chamber is ported to a specific frequency. 

 

When constructing any type of enclosure, you must be aware that the 
outside dimensions DO NOT represent the true (Net) volume inside.  
Such things as woofers, ports, thickness of enclosure material, dividing 
walls, and any internal bracing will reduce the total amount of the 
actual air space available.  The following worksheet has been designed 
to provide you with the necessary steps to accurately calculate the 
absolute (Net) internal volume of any given enclosure. 
 
Calculating Cylindrical Port Volume 
 
1.

Measure the outside diameter of the port and divide by 2 for the 
radius. 

 
2.

Square the radius and multiply by 3.14 (

π

) to arrive at outside port 

area. 

 
3.

Multiply the area by the length of the port inside the enclosure for 
the port volume. 

 

      

Cons 

•

High power handling 
within the operating 
frequencies 

•

Very high output within 
the range of the oper-
ating frequencies 

•

Low power handling 
beyond the tuning 
frequency 

•

Poor to moderate 
transient response 

•

Poor low frequency 
extension 

7 

M ea sure m axim um po ssib le dim ensio ns

M ultiply wa ll thick nes s by 2

S ubtra ct this from e ach dim en sion to
a rrive at G ro ss In terna l Dim e nsion s

M u ltiply LxW xD to arrive at

G ross In tern al Volu m e

Ded uct Vf (volum e of the spe aker fram e )

from G ros s Inte rnal Volum e

B race s?

N o

Yes

C alcu late b race volum e and dedu ct

from G ross Internal Vo lum e

Ded uct Vf (volum e of the spe aker fram e )

from G ros s Inte rnal Volum e

You a re at N et Inte rnal Volum e

in cubic inch es (in )

3

To c onv ert to L ITERS :
Divide in

by 61 .03

To c onv ert to C UBIC FEET:
Divide in

by 17 28

3

3