Enclosure influence on the resonance frequency and quality factor
Acceleration response of the speaker can be calculated by analyzing presented equivalent scheme.
Volume velocity response is written
, where
(electrical + mechanical + acoustic radiation losses ),
(mechanical + acoustic radiation + discontinuity masses ),
.
If we compare this response to that of a screen-mounted loudspeaker, the term that differs is compliance
(assuming that the masses and radiation resistances are identical in both cases). Thus, the addition of an enclosure stiffness to the loudspeaker modifies its resonance frequency as well as its quality factor.
Table below gives the values of resonance frequencies and quality factors for the loudspeaker mounted in a screen and in a sealed enclosure.
System | Resonance frequency | Quality factor |
Speaker in a screen |
|
|
Speaker in a sealed enclosure |
|
|
where
.
