Earl K

08-14-2003, 07:02 AM

Hi All

Originally posted by Giskard

Given a value for Fs of 35 Hz, Mms of 0.055 kilograms, and Sd of 0.090 square meters, Vas SHOULD be ~427.7 liters instead of 274.7.

This is given by:

Vas = (2 * pi * Fs)^2*Mms)^-1 * p0 * c^2 * Sd^2 * 10^3

Where Vas is in liters

Mms is in kilograms

p0 is 1.18 kilogram/cubic meter (mean density of air)

c is 345 meters/second (speed of sound)

Sd is in square meters

- I now have quite a few le14a & le10a with refurbished LansaLoy surrounds. The range of Fs is fairly broad ( 20 to 30 hz ) . I should derive new Vas figures for them. If I can avoid building a dedicated Vas test enclosure - then that's a route I'd like to examine.

- Does anyone know the origin/author of the above quoted Vas formula ?

- & How does it compare or correlate to deriving Vas from a test box ?

best regards <> Earl K

Originally posted by Giskard

Given a value for Fs of 35 Hz, Mms of 0.055 kilograms, and Sd of 0.090 square meters, Vas SHOULD be ~427.7 liters instead of 274.7.

This is given by:

Vas = (2 * pi * Fs)^2*Mms)^-1 * p0 * c^2 * Sd^2 * 10^3

Where Vas is in liters

Mms is in kilograms

p0 is 1.18 kilogram/cubic meter (mean density of air)

c is 345 meters/second (speed of sound)

Sd is in square meters

- I now have quite a few le14a & le10a with refurbished LansaLoy surrounds. The range of Fs is fairly broad ( 20 to 30 hz ) . I should derive new Vas figures for them. If I can avoid building a dedicated Vas test enclosure - then that's a route I'd like to examine.

- Does anyone know the origin/author of the above quoted Vas formula ?

- & How does it compare or correlate to deriving Vas from a test box ?

best regards <> Earl K